Understanding Aerodynamics

If you’ve been reading this blog and especially the ones written about aerodynamics and how it’s being taught, you know I feel like there’s a lot of disinformation that’s being taught by people who purport to know better. Understanding aerodynamics is not as easy as it might first appear, and I’ve been re-examining what I know about it and especially wresting with how to write about and teach it. I consider it crucial to teach it at the most basic level I can while keeping it technically correct. I am unhappy to report that many organizations I have approached about incorrect technical educational issues have shown me nothing but apathy. This needs to change, especially in this age of immediate and widespread information dissemination. The Internet is a great thing; but a lot of stuff you see out on it, especially dealing with aerospace education and aerodynamics in particular, is incorrect. It’s one thing to just be wrong; it’s another thing to line your pockets while doing it.

One of the people stepping up to discuss some of this is Doug McLean, a retired aerodynamicist and physicist from Boeing. (Thanks, Doug, for restoring my faith in physicists.) He has written a book entitled: “Understanding Aerodynamics: Arguing for the Real Physics”. I have seen a different (and I believe original) subtitle that said something like “Common Misconceptions in Understanding Aerodynamics”. Frankly, I wished it had stayed that way to call a spade a spade and raise a flag about what’s going on. Anyway, it’s a good read for anyone really wanting a better understanding of aerodynamics and helps fill in many educational holes even at the college aero class level, since the explanations there often take you through the math..but not the physicality. While that did the job, it often left me with a lot of questions; I’m the kind of person who needs to link the abstract to the real to get it. (And I feel that connection is especially important when you’re trying to teach this stuff to general audiences.) That said, the book is a bit heavy for the layman, so you gotta be really wanting to get into the science to stick with it. You can get a good and somewhat lighter preview of what the book says by looking at the first 29 minutes or so of this video, which is a capture of a lecture he gave an engineering class about the book: https://www.youtube.com/watch?v=QKCK4lJLQHU.

This whole controversy (and it really shouldn’t be one) has been good for me in that it has forced me to re-examine what I learned, find the places where I had misconceptions, drill down into the various technical explanations for lift and drag and see where they were right or wrong. I am even revisiting the technical foundations of my education (physics, calculus, and differential equations) when necessary, and it’s a process I’m still continuing. I’ve got a ways to go before I’m going to feel like I’ve got it down; it’s a lot more work than I thought it would be, and there are days when I ask myself why I’m doing it. But I like both learning and teaching, the latter most of all. At my age, I take a strong look at anything I’m putting a lot of time into since the long term payoff for me isn’t clear; but if it helps me be a better pilot, engineer, or educator…helps me teach the right thing to one pilot or STEM student..then I am convinced it will be worth it, which is why I soldier on.

Spin Training

Author’s Note: This was originally written back in 2011 when I was working on my Light Sport CFI. For another way to get some spin training than the old fashioned “strap your tail into an airplane and then hurl it at the ground”, see the blog “Flying For Flyquest (Part 2 of 3)” dated Nov 27, 2016.)

The requirements for it were not really clear. Both me and my CFI, Dave, had looked at the regulations and they seemed to be saying that even for a Light Sport Flight Instructor, a spin training endorsement was necessary. Regardless, it had been a while since I had an excuse for any kind of flying that turned the world on end, so I agreed to it. On a Monday morning with a cloud-filled sky, Dave rented a Citabria and we launched in it to do some spins.

The cloud deck was a bit of surprise as it hadn’t been in any of the weather forecasts I had looked at. It started moving in from the south, the direction of the Gulf of Mexico, as we were preflighting the Citabria together. We decided to launch because we could see some breaks in the clouds to the east over Galveston Bay, and that was where we were going to do our training. Dave slid into the fabric airplane’s back seat as I tried to remember how to get into the front. Pulling myself up, twisting one leg in and around the stick, and sliding into the seat, I finally sandwiched in. I reached back and grabbed the shoulder harnesses, pulling them over to my waist to attach them to my waist buckle. Once in, I connected my headset to the intercom jacks and pulled the headset over my head, resting it on my shoulders until we got ready to start. My habit was (and is) not to put them on until after the engine and intercom are on in case some reason comes up we need to exit quickly.

I’d gotten a little big in the past decade (I’ve gotten back to “fighting weight” since) and felt scrunched up against the instrument panel, though the control stick still was in a good place and I had plenty of room for my feet in between the rudder pedals when I didn’t need to be on them. The metal stick began moving around on its own; Dave was checking out his control throw. He couldn’t get the stick all the way back up against my seat because it was hitting me, and he felt that we would need to do a wheel landing because of it. While I felt I had enough stick throw to do a three-point landing from the front, I had not flown any taildragger in several years and Dave flew a Pitts as well as this airplane fairly frequently, so I deferred to him and said he needed to do the takeoff and landing instead of me as we had briefed. He acknowledged the call and we started through the prestart checklist, with me controlling the engine start since I was in the front. The engine started on the first try, and I told him he had the airplane. He acknowledged and taxied us forward.

We crossed La Porte’s runway 12/30, heading for 12, though the windsock was showing a little bit of life out of the west. I informed him that the terminal forecasts had shown by ten a.m. that the winds would be two-two-zero at ten gusting to sixteen. That was a little less than two hours away, and he was confident we would be down by then. Still, we talked about the proper control inputs for a crosswind to the right, i.e. , full right stick at the beginning of the takeoff declining toward the center as we gained speed but enough to keep the wind from picking up a wing. We performed our pre-takeoff checklist at the hold-short for 12 and Dave then made a radio call announcing our departure. We rolled onto the runway, aligned with white stripe centerline, the control stick “magically” full right. Dave slid the throttle forward, the engine roared, and we advanced down the runway. The stick came back fairly quickly and we were airborne. The airspeed seemed kinda slow to me, i.e., 45 mph, and I said something to Dave and he thought it was, too, even though the nose attitude looked correct. I looked to my right to make sure the little metal bug cover over the pitot tube was retracted and it was and then looked back at the airspeed indicator and it was showing 60. We both felt the airplane was performing okay and Dave asked me to take the airplane and I did. I continued a shallow climb straight ahead toward an oil tanker sailing into the Houston ship channel while I looked for holes to get us on top of the cloud deck, being also mindful that the floors of the Class B airspace were at 2000 and 4000 feet MSL over the bay, depending on where we were.

Dave asked me to turn to the south to align with some islands he wanted us to use as visual landmarks during the spins. The cloud base was at about 2000 feet and looked to be only a couple of hundred feet thick, but we both discussed our location and concurred we had crossed into the shelf where the Class B floor was at four thousand. I climbed us up through a couple of breaks in the deck, flying east and then south, and as we got glimpses of the shoreline to our east we could tell where we were. Dave asked me to climb to thirty-five hundred to give us some room above our imaginary three thousand foot recommended recovery height. So, I did as we continued cruising south toward what I thought might be a break in the clouds. We found a clearing in the clouds above one of the small islands Dave wanted to use.

“Hey let’s do them here,” he said. “Let me know when you’re ready and give me the airplane.”

“I’m ready,” I said. “You’ve got the airplane.”

He acknowledged he had control and immediately brought the throttle back and the carb heat on.

“I’m going to demo a spin to the right,” he said, as he held the nose where it was and let our airspeed bled off. The airplane didn’t have a stall warning horn; but as we slowed down and I started feeling like we were close to the stall, Dave said he was pulling the stick full back, ailerons neutral, and kicking in full right rudder. He did and the nose rotated right and down; I was suddenly looking straight down at the island below as it whipped around in a blur! As we rotated into the heading we gad started on, the rotation stopped, leaving us diving straight-nose down! As Dave pulled us out, the G-meter needle rolled to 3 g’s; the power came up and we moved back into a climb and I heard: “Your airplane!”.

“I’ve got the airplane,” I said, taking the stick back and continuing the climb. I had noticed as we were spinning down that there was more of a hole to the north than to the south, and that hole gave me more ground reference to work with. So, as we climbed, I turned us back to the north and steadied up in the direction.

“Your turn,” Dave said. “I want you to demo a one turn spin and recovery.”

“Ok,” I said, just as we hit our altitude. I immediately throttled back and brought the carb heat on while slowly bringing the stick back to hold the nose in a level flight attitude, telling Dave what I was doing as as I did it. We slid slower, slower, and NOW! Stick full back, I kicked full right rudder and held it in; the airplane rolled over like a dying hippo and spun, heading straight down! About a quarter turn before I hit my entry heading, I kicked full opposite rudder, quickly kicking it back to neutral as the rotation stopped while I simultaneously came forward on the stick, a bit too aggressively. We kicked into a very slight zero-g dive, which I quickly negated by beginning the pullout, shoving the throttle to full as the nose came up through the horizon.

“Nice job!” Dave said.

“Except for the part of floating you a little bit,” I laughed.

“I’d rather see you recover aggressively than not aggressive enough,” he countered.

Well, it was, as flying often is, a matter of “how much”. It had been just a small float, and I had essentially just “unloaded” the airplane which amounted to giving Dave a free, one-to-two second weightless ride he probably hadn’t anticipated. But a harder negative g recovery in another airplane, like the Pitts Dave often flew, could flip the airplane into an inverted spin. Ok, so it would take a LOT to get there; but still, it was a matter of degree.

We climbed back up and Dave took the airplane to demo a spin to the left. The nose did the same familiar slice and roll, and again tucked into a fast, rotating, near-vertical dive. Propeller driven airplanes often spin faster to the left than to the right because the engine torque adds to the rotational force with a leftward spin, but I didn’t really notice any difference. All I knew was that once it broke loose, the nose attitude down ad the rotational rate was steeper and faster than I remembered it. Despite my anxiety at not having done anything like this for quite a while, I was enjoying the hell out of it!

Dave gave the airplane back to me and as I set up, he emphasized that in this airplane the rudder force to get full left rudder was much higher than it was to go right. I acknowledged that as I immediately throttled back (initially forgetting the carb heat until reminded) and slowed us down and down, until we hit the stall and I kicked full left rudder. Again, the airplane rolled over and spun down; and again, as I neutralized the controls and stopped the spin, I floated us for a second before beginning the pullout and bringing us back up into a climb. During both his set of spins and mine, we were averaging five to six hundred feet altitude losses. We climbed back up toward thirty-five hundred feet as Dave talked to me about doing “incipient spins” next.

“I’m going to pretend I’m a student doing stalls and then do something wrong that starts us into a spin,” he said. “I want you to take the airplane and recover it.”

I acknowledged I was ready and watched as he leveled us back at thirty-five and began slowing the airplane down. Everything was going fine as we slowed into a stall but at the break, the airplane began rolling right, the nose slicing into the now ever-familiar signature of an upcoming spin. I called “My airplane!” as the bank hit about forty or fifty degrees, taking the stick and pulling the power back, rolling wings level, and then executing a pullout, adding power to get us back into a climb. Dave complimented me on the recovery and then took it and did it again, this time getting the airplane to break left. I took control of the airplane and got us righted again, losing only a couple of hundred feet…if that. Again, Dave complimented me on the recovery.

“Well, that’s all the training we have to do,” he said. “Is there anything else you want to do?”

“Yeah!” I answered. “Let’s go do another spin!!”

I started climbing for our altitude, looking forward to doing a spin for fun!

Dave asked me how much gas had in my left wing. I leveled the wings and the gauge needle was bouncing around close to a quarter of a tank, but the right wing gas gauge was bouncing between quarter and zero. While we didn’t think we really had a gas feed problem, we both agreed that the prudent thing was to knock it off and head back to the field where we could check it out on the ground. I dived us northward toward home field through a hole in the clouds; and once the airspeed and attitude was stable, the right wing showed about half a tank, closer to what we had been expecting. By that point, we were closer to home than not, so I decided to call it a day anyway. I felt good about what we had done.

I leveled us at a thousand feet about six or seven miles out from the airport and turned the airplane back over to Dave since he was performing the landing. We initially set up for a crosswind landing on 12 but then changed to runway 23 once we saw the windsock and that the winds had changed. Dave couldn’t see the airspeed indicator, so like I had done in my F-14 RIO days, I called airspeed for the pilot as he brought us down the approach. With just a slight “clunk”, Dave did a really nice wheel landing, brought the nose down once we had slowed, and taxied us back in.

I have to say that even though I had been an aerobatic pilot in my past, taking spin training for my Light Sport CFI was well worth it, required or not, and something I recommend to anyone going for their Light Sport rating, whether as a pilot or CFI. You probably will have to look elsewhere than where you are training in your Light Sport to find a spin certified airplane, though light sport aerobatic planes are hitting the market now, so who knows? No matter, have your favorite flight instructor or one he/she recommends to conduct this training and go with tim to spin around. It’s one or two hour of flight training that can save your life.

Eyeballs Out!

I saw the yellow J-3 Cub fly into the downwind and then, when abeam the threshold of runway 14, turn left and nose down onto base leg. The airplane was close aboard and arcing quickly over to intercept the final approach to the runway. It was approaching the threshold and only about one hundred feet in the air when a Cessna 152 sitting at the hold short pulled out onto the runway in front of it. I couldn’t hear the Cub’s engine, but its pilot reacted immediately; the Cub leveled off, flying over the top of the Cessna. The Cessna sat frozen, its pilots made aware by the Cub’s shadow and its presence overhead that they had almost caused a collision.

I didn’t have my handheld radio with me, so I was uncertain if the Cub had broadcast its position in the pattern. If it had a radio at all, that is. It was probably not equipped with one. Even if it had been, the fact that the pilot didn’t use it was irrelevant. No one is required to make any radio transmissions in the pattern at a non-towered field, something many pilots either aren’t aware of, forget, or ignore.

When you’re engaged in a dogfight, you quickly learn the only thing that’s going to keep you alive is your visual lookout, no matter what technology is onboard. I call that being “EYEBALLS OUT”! (Yes, the term is used more routinely to describe the direction of g-forces one is experiencing in the cockpit; but it’s appropriate to use it here to distinguish where one is looking.)

Yes, the Airman’s Information Manual and other aviation safety materials recommend radio protocols for pilots to use to stay informed of each other’s position in the traffic pattern. That communication is very helpful and certainly best practice. But I’ve often heard comments that make it clear we EXPECT other pilots to use the radio and often consider it poor form when they don’t. Well, it is, but that expectation is OURS and can be and often is unrealistic. Your best advice in this matter comes from the movie “The Princess Bride” where the Dread Pirate Roberts tells Montoya, “Get used to disappointment”. If you have become dependent on radio calls to keep you safe in the pattern, the problem is yours and you are likely to find out the hard way when your belief and your practice is badly placed.

The only thing that’s going to keep you safe in the pattern…or in flight…is your EYES! If you’re taxing around the airport or flying the pattern convinced that the radio is going to keep you safe, you have, as we also used to say in fighters: “your head up and locked”.

I was taught when checking traffic at a non-towered field to do a 360 on the taxiway before pulling forward toward the runway for takeoff. I teach this to my students. That said, my CTSW has a very wide turning radius and some taxiways at smaller airports don’t support it, so I’d be lying to say I always perform it. What I always do, however, is make sure I visually sweep the entire downwind and then turn my airplane enough to ensure I can see all the way down the final approach and about twenty to the thirty degrees to the side opposite the pattern before pulling forward toward the hold short. This ensures I not only see anyone coming down the final approach but anyone who has overshot final and is correcting back or is approaching the final from the other side. This is especially critical at airports where there is helicopter activity, where they may be flying downwinds on the opposite side of the pattern to the fixed-wings. (This is a strong reason to take the time to perform the 360 sweep, as long as you’re really paying attention to it and not just going through the motions assuming no one is there.) And anything you choose to do to assist your visual lookout MUST take into consideration the blind spots in your aircraft; it’s up to you to know where they are and do what you need to in order to work around them.

It’s no less critical to stay “eyeballs out” at towered fields. Most mid-air collisions happen within 5 miles of an airport; and whether the field is towered or non-towered seems to make no statistical difference. The radios can help you get or maintain situational awareness for things you can’t necessarily see; but, in the end, it’s your eyes and your reactions that are going to keep you safe. The regs require you to “see and avoid” even if you are flying IFR (as unfair as that might sometimes seem.). Additionally, today’s technology laden cockpits lure us all to be “eyeballs in”, a problem that’s going to be made worse by ADS-B. It’s great to see that target you can’t see on your iPad and maneuver early to avoid it, but if you smash into the airplane not displayed while doing so, you haven’t gained a thing.

Instructors have to work twice as hard at keeping a lookout; trying to keep tabs on what their students are doing pulls their eyeballs in; so, if you’re flying with one, keep your eyes moving and help make sure you both come back from the flight alive and unhurt. And, Instructors, all of us get engaged with something they are doing and keep our eyes too much inside; but we are also supposed to be setting an example and keeping things in perspective. During many flights, we are the Pilot in Command; so, if anything unfortunate happens, it can be ultimately on us.

There were two people in that Cessna 152.

Safety Standdowns for General Aviation

After a significant accident or incident involving flight operations, my Navy squadron would halt all flying to conduct a day-long review of various safety subjects as closely related to the accident or incident as prudence allowed. This break in our operational routine was called a “safety standdown”; and it was designed to make sure we had our heads screwed on right about taking risks. It was one thing to lose aircraft and aircrew due to combat; it’s quite another to lose them to preventable accidents. It was an effort to reinforce “better dead than look bad” or “it can’t happen to me” really doesn’t work, something some folks in aviation just don’t get.

We all have accidents, sometimes minor and sometimes, serious, happen at our airports. I don’t know about you but all that often happens afterwards is I pick up gossip about what went wrong, at least until the NTSB report comes out…if there is one. Too often, though, even when an accident reaches Part 830 thresholds to become reportable, unless it makes the evening news, we pilots hear nothing. (And that’s even MORE true for accidents that don’t trip the 830 threshold.) That’s exactly the opposite of what would make for a safer community. Over and over, in the safety world, we learn that open and honest communication about what went wrong is what helps the world become safer, though it still only occurs when the practitioners of whatever dark art we’re talking about take the lesson provided to heart.

Just before the holidays, we had four significant accidents associated with operations at our airport within about six weeks. Two of them were fatal and one involved significant injuries. Three of them occurred during or shortly after takeoff and one during the landing phase (the most risky parts of the flight profile). The latter was the only one not involving an injury or fatality but did disable the aircraft. The accidents involved both flying clubs on the field and one private individual not based there. Though these were certainly not the first fatal accidents that had occurred out there, the number and severity of the accidents within the short timeframe got lots of folks’ attention, including mine. The initial lack of response from anyone appeared deafening to me, and I brought up the subject with some of my compatriot instructors, some of whom also have military and/or safety backgrounds. Everyone thought a safety standdown was a good idea. Eventually, one did happen…almost. A FAAST event was put together at one of the flying clubs, though the notification announcing it was not widespread or much in advance. The flying club involved in one of the fatal accidents had an instructor give a brief review of stall/spin factors (though it was too rushed for my liking); a pilot’s organization rep gave a brief on airport pattern operations that was, unfortunately, tainted with incorrect gouge (something another flight instructor next to me agreed with me on); a helicopter training school gave a helpful brief on helicopter operations (they were fairly new at the airport so the fixed wing guys were adjusting to their presence); and a group of formation flyers introduced themselves. I felt some of it was helpful, some of it was better than nothing, but the whole experience could have been improved with more focus. A “safety standdown” is different from a safety seminar in that the latter may cover related accident causes (or suspected accident causes if the probable cause has not been established) but a safety standdown is aimed right at them. That does not exclude it from including other safety related material that might be relevant, but its primary focus is aimed at the events that triggered it.

Because we’re talking about this in relation to general aviation and not a centralized authority (like a military command), someone has to take the bull by the horns and get it going. Any flight school or flying club can decide to do it, and it will achieve maximum impact if associated flight operations are halted during it. This would have to last long enough to send a strong signal that safety is being taken seriously, i.e., a minimum of two to four hours, depending on the quantity of relevant material and the significance of the trigger event(s). In the event there are multiple clubs or schools, the airport FBO or management could call for the standdown and act as the focal point for putting it together and hosting the activities. Each flight school or flying cub could provide safety officers, CFI’s, or other knowledgeable pilots to a working group that would discuss the events and trends they have been seeing and then decide on the content, timing, and location of the event. FAAST/FAA Wings credit for attendance should go without saying; FAAST subjects that might relate to the events could well be prime candidates for inclusion, even when the probable cause of the trigger events are only suspected and not known. This is not the same as speculating on the probable causes; that needs to be avoided; but there is little new in the causes of most general aviation accidents. Related safety information will be available.

So, okay, that’s the ideal. Not every airport manager, FBO, flight school, or flying club is going to be willing to stop all flight operations. While doing so will provide maximum benefit, you can still make it work by letting flying continue and making attendance at it totally voluntary. The other logistics of it need to remain the same, i.e., the agenda needs to be matched up with the events being targeted. Take video of the presentations and make them available for those who wanted to come but couldn’t for whatever the reason. If you have a newsletter, either electronic or paper, you can include information about the highlights of the events, including any lessons learned or changes to operations that might come out of them.

Additionally, maximum benefit can be gained by making the event, as much as possible, an interactive exchange between the presenters and the pilots in the room. It’s an opportunity to not only impart wisdom from the podium but gain some from the folks in the room. Almost every gathering of this type will be filled with pilots from a myriad of backgrounds…some military, some general aviation, some from the business aviation community, and some from the airlines or some with parts of them all. Encourage those with experiences that relate to the topic to share them; it not only helps us get to know each other better but it opens the door to tapping the wealth of experiences whose depth we would otherwise have no knowledge of. It also reinforces the idea that anything can happen to any of us; and, if it does, knowing how someone else handled it, good or bad, might help us make the outcome go our way.

(Author’s Note: Thanks to Jim Gardner,ATP/CFI and Russell Lewey, Educational Director for FlyQuest, for their input to this article.)

Flying the Circular Pattern: Thoughts from a former F-14 RIO and current Light Sport CFI

The University of North Dakota and AOPA’s Air Safety Institute is performing a study of the use of the circular traffic pattern at general aviation airports. This type of pattern has been in long use by the U.S. military, with the Air Force and Navy using it as the emergency approach pattern and the Navy using it as the pattern of choice…at least since the British pioneered its use to get the F-4U aboard ship. I’ve flown the pattern as both a pilot and a RIO and use it today when flying simulated engine out approaches in my Light Sport Flight Design CTSW. I also work as a part-time safety analyst for the Flight Safety Office at Jonson Space Center, so I‘m content to wait for the study’s results and seeing their recommendations before formulating aa position. What I’m going to do here is detail some caveats centering around the Navy’s operating environment that affect its use and how that translates into the environment at a non-towered airport. Hopefully, the students conducting the study have some ex-Naval Aviators and USAF pilots at their disposal; not sure if the Army uses it, but if they do, then some insight from some Army pilots cold be helpful as well.

The Navy’s primary use of the pattern is to safely get aircraft aboard ship. It provides enhanced visibility of the landing environment (i.e., the ship and its position) and allows for smaller, more gradual, and continuous adjustments of your position to arrive on a final approach with consistency, something critical to the tight requirements needed to get aboard. Crews can and do use altitude gouges to judge glideslope at the 90 degree degree “to go” turn point (450 ft AGL) from downwind pattern altitudes in the same basic range as general aviation patterns (slightly lower than most actually; the F-14 NATOPS pattern was at 600 feet AGL). The pattern is intended to provide a stabilized approach beginning at the downwind abeam point. The aircraft hits that target “on speed” (green chevron on the AOA indicator, 15 units Angle of Attack for the Tomcat) and in the final landing configuration. That is gear down, flaps down, speedbrakes out (if applicable); no other major changes in aircraft configuration are made after that point since any changes in aircraft configuration can cause a major upset to an otherwise stabilized approach. Variables for the Navy pilot to deal with are therefore narrowed to controlling altitude and angle of attack and judging the rollout onto final (which will be slightly to the right of the ship’s wake to line up with the angled deck), followed by “Meatball; Lineup: Angle of Attack” until touchdown or bolter. The aircraft’s “locked down” configuration MUST be taken into account when discussing the stability and precision of the circular approach and before applying it to general aviation where that is often NOT the case. The FAA Flying Handbook instructs pilots not to go to full flaps until established on final and some preceding amount of flaps are applied sometime after the downwind abeam point, not ahead of it. While this is to give you the best glide possible in case of an engine out, it still means you’re going to make one of the most significant configuration changes you can make while also trying to get into an airspeed and descent rate stabilized approach. While the impact is more a function of the aircraft being flown than the type of pattern, but understanding the impact of configuration changes is a necessary part of evaluating the overall use of the circular approach and its for stability. You could decide to put the airplane in its final config and then count on the power being there as the Navy does and get all the benefit; but it’s unlikely that would be the case, even if the probabilities were to tell you that protecting for an engine out in the pattern might not be a good trade considering the safety gains of approach stability. This must be considered by the team conducting the study.

Likewise, the team needs to consider the fact that few Naval aviation operations take place in a nontowered environment. The closest thing to it are operations at Navy Outlying Fields (NOLF) used primarily for pattern training and that often have someone on duty and on the radios. While they are primarily there to make sure no one lands gear up, they also act as a traffic advisory service. Operations at other Navy airfields (and some NOLF’s and aux fields) are run by Navy air traffic control towers; aboard ship. the Air Boss and his staff take on the roll of an ATC tower. This significantly limits the opportunity for traffic conflicts due to someone making an unexpected/unannounced straight in or unorthodox pattern entry. When applying the circular pattern to nontowered genreal aviation operations, then, this means a very big question is, for the pilot in the pattern as well as anyone approaching the pattern, whether it introduces more risk to “see and avoid” than the rectangular pattern does.

For pilot in the pattern, since the transitions to each leg are performed in a constant turn, visibility of incoming traffic will be directly affected by whether the aircraft is high wing or low and the amount of bank used. Belly checks (rolling wing down in the direction of possible incoming threat…uh….traffic) may be employed to look for traffic blocked by the upturned wing; and, if used, become a factor that can destabilize the approach. (Scanning for someone on final approaching from the outside is done by just turning your head in a rectangular pattern.) This can be mitigated by using shallower angles of bank, which would be more necessary in a low or mid wing than a high but can mitigate the issue. Of course, the shallower the bank, the more stretched out from the runway the pattern becomes; but my guess is it would probably still be significantly less than the stretched out rectangular patterns I see too often at nontowered fields. For the pilot approaching the pattern, the additional turning of the aircraft in the pattern may them a bit easier to spot; in a rectangular pattern, there are large portions of it where the airplanes in the pattern may be climbing or descending but are wings level and not the easiest to spot.

These are things I expect the study to evaluate. Personally, I like the circular pattern; and as I’ve said, I will often fly it when performing simulated engine out approaches in my CTSW. I have also demonstrated it to students and friends who are curious about how the Navy does things. I don’t tend to use it when flying a Remos GX; its higher approach speed and less effective flaps make flying a rectangular pattern a more comfortable thing to do and what I need to teach my students to do. While I’m content to wait and see what the study arrives at, with the investment the community has in both training and operations in the rectangular pattern, I think it’s going to be a “hard sell” to move us to a circular pattern. There must be a very significant benefit not otherwise achievable to make it happen. I also think there are bigger fish to fry; the factors that drive loss of control in the pattern aren’t things that this protocol are going to affect. The collision risk may be another story; but it seems to me that could go either way. If we were to switch to a circular pattern, you could probably expect accident statistics to initially get worse until pilots got trained and comfortable with the new way of doing business.

No matter what pattern we ultimately fly, good headwork, situational awareness, and skill are what we need to determine whether flying on any particular day goes well or goes bad. When those things fail, all you’ve got left is a little luck. Hopefully, it goes your way…

Flying a CTSW with Flat Plate Wings: Analyzing “Impact Lift”

I wrote a blog a little while ago entitled “One Form of Lift” which talked about the generation of lift and how there was, from an engineering standpoint, no such thing as “impact lift”. Classical engineering analysis only uses lift (which is primarily generated by pressure flows around the wing) and drag. My assertion is that most or all of the force people are calling “impact lift” is really drag, but was there a way to prove it by using a real world example? To take a look at that, I decided to analyze what happens if I stick a set of flat plate wings on my light sport aircraft, a Flight Design CTSW.

We will assume that the wings on the CTSW are mounted so that they are at zero degrees angle of attack (and angle of incidence) when the airplane is sitting level. The wing area of a CTSW is 107.4 square feet and the airplane’s max gross weight is 1320 pounds.

The equation for lift is: Lift = ½ D V2 S CL where D= air density, S = wing area, V2= the velocity squared, and CL = the coefficient of lift.

The equation for drag is of the same form, i.e., Drag = ½ V2 S CD where = air density, S = area being analyzed for drag, and CD = coefficient of drag.

For these formulas, lift=weight, the density of air at sea level is used, and S= 107.4 sq ft.

A flat plate has a lift coefficient, and the curve maximum hits a CL = 0.7 at an angle of attack of approximately 12 degrees.

SOURCE:http://home.planet.nl/~kpt9/The%20boundary%20layer.htm

At twelve degrees’ angle of attack, then:
Lift = ½ (.002378 slugs/ft3) V2 (107.4) (0.7)

For the airplane to fly, lift must equal to weight, so:
1320 = ½ (.002378) V2 (107.4) (0.7)

2640/(.002378*107.4*.7) = V2

2640/0.17877804 = V2

14,767 = V2

121.5 = V (feet per second) or 72 knots

This would get my CTSW with a flat plate wing off the ground at 72 knots while nibbling at the stall. Let’s say you understand this will be the case and elect to back off on the liftoff a bit, flying off at approximately 8 degrees angle of attack. (I believe you will either strike the tail of the CTSW at 12 degrees or be very much at risk of it.) So, when would you want to rotate? At that 8 degrees, you have a lift coefficient of 0.6. That gives you:

2640/.153238 = V2

17,228.1 = V2

131.25 =V (fps) or 77 knots

Since the CT actually gets airborne as low as 42 knots with flaps and about 50 without, you get an idea of the work a good airfoil design (using Bernoulli’s) is doing for you. You can “reverse engineer” the lift coefficient at those speeds by substituting them in for V and solving for CL.

Doing so for the no flap configuration and 50 knots yields a CL = 1.45; in other words, the shaping of the airfoil increases the “flat plate” lift coefficient by slightly over 100%. (The use of flaps yields a lift coefficient of 2.06…which is part of the reason why it leaps off the runway and feels like you’re in an elevator going straight up…)

But, let’s go back to flying by the flat plate alone since our real target is to examine the idea of “impact lift”. As I said in an earlier blog, the only way to do this from an engineering standpoint is to use drag as the “impact lift” force. There is no accounting for such a thing in conventional performance analysis (which should tell you something in and of itself about the rigor of the idea, despite some folks trying to discount how engineers do it).

Let’s see how we might be able to generate enough “impact lift” (drag) to fly. A flat plate has a drag coefficient of 1.28. Since the equations for lift and drag are the same and we’re considering the same area in both equation sets (i.e., only the area of the wings), then we can shortcut the calculation of the total drag force the wings can generate by simply taking a ratio of 1.28/0.7 = 1.83. Then, that same 1320 lbs of total force…now as drag instead of lift…would be generated at 72/1.83 = 39 knots. But this would be for a CTSW wing deflected at 90 degrees to the windstream (and the fuselage). Since we’re just trying to use “impact lift” (i.e., drag) to get airborne, the max lift would occur at a wing inclined 45 degrees to the windstream. The “lift” would be equal to the sine of 45 degrees times the total force. The sine of 45 degrees is 0.707. So, then the speed at which you’d have just enough drag acting vertically to lift off would be: 39 knots/0.707 = 56 knots.

However, for this to occur, the drag acting in the horizontal direction would also be 1320 lbs (sine and cosine of 45 degrees…the horizontal and vertical force components would be the same). Let’s see if the Rotax 912 can get there.

Using Thrust = (HP*efficiency*326)/KTAS and assuming we have a 0.8 propeller efficiency:

1320 = (100*.8*326)/KTS

1320 KTS = 26,080

KTS = 19.75

This is the speed the Rotax could attain in this “lift/drag” configuration. This is a conservative answer since the airplane will have more drag area than this, i.e., we did not account for the frontal area of the fuselage or other components. This puts us well short of the approximate 56 knots it would take to get airborne. To see how big an engine it would take, let’s use the same formula and solve for HP.

1320= (HP*.8*326) / (56)

1320 = (260.8HP)/ (56)

1320*56 = 260.8 HP

73920 = 260.8 HP

283.4 = HP

So, it would take an engine producing almost three times the horsepower the CT has available which would increase the weight and cause us to do all these calculations over again. Keep in mind, too, that we are only talking about the power it would take to get the CT into the air since climb rate is a function of excess horsepower. The engine would have to be bigger still. (At least a 300HP IO-540…) What the numbers are telling you is that the idea of impact lift doesn’t work, and that’s before we try to consider the flying characteristics and design of the flight controls for such a beast. We know that increasing camber (curvature) of an airfoil causes an increase in lift and that’s what makes ailerons and elevators work; how do you explain what’s happening if “impact lift” (drag) is the only force?

“Impact lift” is a misnomer and a popular myth, like saying you can discount Bernoulli’s principles and just use Newton’s laws to easily explain how airfoils work. Good luck with either. From both an engineering and piloting standpoint, it’s better and proper to see lift as a result of Bernoulli’s (i.e., pressure distributions) principles and drag as something that needs to be overcome and is not your friend (except when trying to slow down). You’ll not only stay safer that way but you’ll teach your kids the right concepts, making sure it is “as simple as possible but no simpler”.

AUTHOR’S NOTE: Many thanks to Dave Witwer, Jim Gardner, and Matt Zwack for their review of the drafts of this blog. They’re all pilots and aerospace engineers (Dave, Jim and I worked at Johnson Space Center and Matt works out at Marshall Spaceflight Center.) Great guys I’m honored to know as colleagues and friends!

Fuzzy Aerodynamics

A week or so ago in an aircraft owner’s forum, the exact thing I was concerned about happened, i.e., a pilot trying to explain how an airplane creates lift to a newer pilot started talking about “the downforce” under the wing that pushes an airplane up into the air (you know, because that’s how the reaction force…referred to in Newton’s Third Law is created…and the airplane reacts by going up!). I’d think it was funny but AOPA’s current iteration of “Essential Aerodynamics” also says that a wing pushes down on the air, creating a misperception that will probably take a decade to clear up. It’s not that Newton’s Laws are not involved; they are. The popular misunderstanding of what that means is fostered by the incorrect idea that somehow only Newton’s laws apply and Bernoulli’s laws are somehow incorrect and is all pure nonsense. So, I’m going to give you a technical explanation of why and do it without going into a lot of math. (I’m going to assume you’re not too dumb to follow what I’m saying, unlike some other folks who say we don’t need to teach aerodynamics like engineers do it because we’re not designing airplanes and then screw the whole thing. If you’re new to this controversy of befuddlement and want to get completely spun up, see the blog entitled “When Simpler Becomes Dumb”, another entitled “Only One Form of Lift”, go through AOPA’s “Essential Aerodynamics” presentation, and come back here. Otherwise, just read on; I’ll explain it in enough detail where you can grasp the core issue.)

The text we used in my aerospace engineering classes discussing aircraft performance was “Airplane Aerodynamics” by Dommasch, Sherby, and Connoly. Section 2:4 “Development of the Bernoulli Equation” explains how,by analyzing a small packet of air as it moves using Newton’s Second Law (F=ma) (Spoiler alert: Newton’s Third Law is not involved here) and assuming no mechanical or thermodynamic losses (conservation of momentum and conservation of energy),one derives Bernoulli’s equation. For incompressible flow (a good assumption for flows less than 200 knots or 230 mph), Bernoulli’s equation is:

p+(D(V2))/2=constant

where p=Pressure, D = air density, and V2=velocity of the airstream squared. P is the “static pressure” term and “D(V2)/2” is the “dynamic pressure” term. So, as the velocity of the airflow increases, the dynamic pressure (pressure in the direction of the airstream flow) increases and the static pressure (pressure of the mass of air and measured perpendicular to the flow) decreases.

Section 4.3 of that text is entitled “Development of the Lift, Drag, and Moment Equation”. It starts out with this: “…the only forces that can act on an object moving through a fluid are those produced by friction (shearing stress in a fluid) or those produced by pressure. Except for when minimum drag is considered, the pressure forces are by far the most important and completely responsible for the production of lift”. (NOTE: I know the reference to “minimum drag” creates a question; I’m researching that and will post an answer here once I have it.) It then goes on to discuss the generation of the force equations associated with deflecting a small packet of air using Newton’s Second Law (F=ma) to calculate the force produced. After showing you the answer, it states: “An airfoil..produces lift by changing the momentum of a given stream tube of air and is capable of producing a force greater than that predicted by the use of simple energy solutions.” In other words, an airfoil produces more force than can be attributed to this simple calculation (F=ma) alone.

So, the blind use of Newton’s second law doesn’t account for the total amount of force generated by an airfoil (or a wing). Notice, too, this analytical approach uses a “microscopic” viewpoint to derive the equations, a common practice when starting at the bottom of an engineering or scientific analysis. How can you figure out what the lift is practically? By stepping back and examining the pressure distributions around the airfoil and calculating the forces they generate. This is easily done, which is why it’s routinely used. (This is using Bernoulli’s principle, folks.)

Have we disregarded Newton’s laws? Not at all! And in doing so, we have generated Bernoulli’s principle, which gives us a more practical and easier to understand approach to working with many aerodynamic problems. Not only does its use make engineering solutions easier, but using Bernoulli’s principle makes for an accurate and easier to understand explanation for the layman. How Newton’s laws apply to aerodynamics is not intuitive; and as we’ve already discussed, often leads to misperceptions, especially when understanding of the subject is incomplete. It’s easy to jump to incorrect conclusions based on what we are familiar with, and most people seem to latch onto Newton’s Third Law, which we see in common thrust/acceleration relationships. Because of that, it jumps into the forefront of thought much more than Newton’s first (i.e., an object at rest tends to stay at rest or continue moving until acted on by an outside force) or second (F=ma).

There’s a more important reason to talk about Bernoulli’s principles when teaching aerodynamics to pilots. When I use Bernoulli’s to explain what’s happening with lift, I not only stick to a technically accurate explanation; but I continue to make a linkage back to airflow around the wing, which for a pilot is the critical thing to control. It’s easy to see the case surrounding controlling the angle of attack to keep from disrupting the airflow controlling the lift. If you try to explain how a wing works using Newton’s Third Law, you will probably think the wing creates a downward jet of air as our wayward pilot did. It does in the form of downwash around a wing but its primary effect on lift is to create induced drag by canting the lift vector rearward and decrease the effective lift the wing produces; to use Newton’s Law second and third laws to find the lift you have to calculate the TOTAL change in momentum of the flow field around the aircraft (and not all of that is going to be in the vertical plane). Want to teach that in your pilot information classes? Better be ready for calculus and lots and lots of work!) If you have a pilot thinking he can create more lift by increasing the wing’s “upward” reaction, you also just created the potential for having a pilot INCREASE back pressure when he encounters a stall to increase the downward force of the “jet” or create “impact lift” (if you teach that concept, too). Poo-poo that possibility if you want; but you can never predict how someone with the wrong idea will react or when you plant the wrong information on their head. I believe it’s a very bad idea to teach anything that is technically incorrect or that can be easily misconstrued into a bad result.

So, the next time you hear that only Newton’s laws apply to aerodynamics and Bernoulli’s don’t, hopefully you’ll understand there’s no way that can be true. Explain that Bernoulli’s equations COME FROM an analysis of the behavior of an airstream using Newton’s laws (Newton’s second, mainly), and you CAN’T DISCOUNT ONE WITHOUT DISCOUNTING THE OTHER. In fact, trying to make the case that “only” Newton’s laws apply can only be correctly understood by PERFORMING a very in depth technical analysis as I have discussed; and that makes understanding the subject harder, not easier. As Einstein said: “Make things as simple as possible. not simpler.”

Because when you take it past that point, you make it wrong.

Flying for FlyQuest (Part 3 of 3)

Guillermo and I manned up the CT the next morning at a little before eight a.m., started her up, and then taxied out to KMDQ’s runway 18. There were very few clouds and the visibility was great as I took us into the skies and turned us west toward Athens, our first checkpoint on Guillermo’s flight plan. I switched us up to the frequency for Huntsville Approach but didn’t check in since we were staying north of the Class C airspace. Ahead of us, a Boeing 737 was climbing out from Huntsville International airport and turning west, climbing up and away. I gave the airplane over to Guillermo at about two thousand as we headed for forty-five hundred. As we did, I spotted another light plane flying toward us at about a thousand feet below; Approach wasn’t talking to him. I puzzled over what type of airplane it was until I recognized it as a T-34 Mentor, one of my favorite airplanes to fly. I had gotten a fair amount of time in them while in Navy flying clubs in San Diego and Corpus Christi, including one flight with my then-wife into Spaceland airport south of Johnson Space Center (JSC) in Houston. I had met an intern working there who sponsored a tour for us which resulted into me flying a forward cockpit Space Shuttle simulator, a precursor to what I would spend a decade doing about eight years later. (Spaceland would later be called “Houston Gulf airport” when I was working at JSC, and I flew out of it for many years before it was sold and turned into a housing development. It was sold shortly after 9/11; it was a private, public-use airport reportedly owned by a brother of Osama Ben Laden (Salem bin Laden) who had been killed in 1988 while flying an ultralight north of San Antonio.)

The T-34 passed well clear below and slightly to our right and underneath while we continued on to our checkpoint and leveled off at our cruising attitude before turning south-southwest. There was a bit of mist in the air that lowered visibilities a little but I still thought we had around ten miles and not a problem. The ride was smooth as we passed over Wheeler Lake and the outlines of Decatur, pointing the nose toward Walker County-Bevill (KJFX) where we had landed on the way up. Guillermo was tracking a bit west of his course line and wasn’t picking up on it until I pointed it out; we corrected as we got close to JFX and then tracked true as we turned slightly more westward toward Downer (You gotta hope the airport is named after somebody and doesn’t reflect the experience there.). We passed under the Meridian East Military Operations Area (MOA); and though it was active, its floor was at 8000 feet so we were well underneath it. Soon, Aliceville, Alabama, the last town we would see before crossing the western Alabama border, was passing beneath us with Downer’s single runway beyond. After I made the customary traffic alerts (i.e., call sign, position, intentions) on 122.8, we crossed over Downer and headed into the flat, green lands of Mississippi, continuing on a southwest line that took us just north of Meridian. We tracked toward Easom (M23), a small airport just southeast of Newton, Mississippi and west of Meridian, while passing within sight of an untowered auxiliary field belonging to Columbus AFB, a towered Navy Outlying Landing Field (NOLF) to our north, and Naval Air Station (NAS) Meridian and Key Field to our south. Pressing on underneath both Meridian 2 East and West MOA’s, we motored on to Prentiss-Jefferson Davis, our last airport/checkpoint before reaching McComb.

Cumulus clouds were staring to dot the horizon ahead, so we knew were moving toward more moist and less stable conditions. There were scattered clouds at our altitude as we approached McComb, and we navigated around them as we pressed toward the airport. I had Guillermo start our descent when the GPS showed we were hitting our descent profile of 500 feet per minute, and the chop picked up a bit as we descended. About ten miles out, I took the airplane back to give myself time to get the airplane set up the way I liked it for downwind to runway 15. We made our approach and landed with fifteen degrees of flap slightly past the first and only turnoff before the end; I braked us to a near stop before making a radio call and back-taxiing on the runway to the FBO.

After our customary break for drinks, bathroom, and fuel, we manned back up and launched out toward Houston with me flying my regular GPS course.
mcbry15to
Taking off from KMCB’s Runway 15

The clouds started thickening up, but I still wanted to get above them, so I climbed the CT up to 6500 feet to reach a smoother, cooler ride. But as I got us there, I realized the tops were building rapidly and the bases were slightly descending; that plus a weather report showing broken layers at thirty-three hundred feet over Beaumont made me reverse my plans and head back down. We would make our way underneath to maintain legality under Light Sport rules at 2500 feet.
wxeval
Making the decision to descend back down.

As we pressed toward the Mississippi river, the air turned a more milky white, the visibilities dropped a bit, and the clouds started closing up the spaces above us.
msriver
Approaching the Mississippi River

We spotted some ground fires from what looked like controlled burns we knew were responsible for smoke that was generating the milkiness; the air cleared slightly as we flew across the Mississippi, heading into western Louisiana the NEXRAD weather on the GPS was showing dotted with showers. None of them were on the immediate courseline but some were fairly close, so we decided to watch them for movement and growth but defer any diverts (unless we saw “red” on the NEXRAD) until we could see them out the window. We heard a jet calling as it approached Eunice (4R7) for landing as we were just west passing over St. Landry Parish-Ahart (KOPL) about ten miles away. As we approached Eunice ourselves, we heard the jet’s pilot calling that he was taxiing for takeoff and I responded by announcing we were about to pass over at 2500 feet headed southwest. We watched him taxi out and flew right over him, calling we were overhead and then again when we were a few miles west. He headed south and posed no conflict.
lakecharles
The weather as we approached Lake Charles, LA.

The clouds thinned out as we passed Lake Charles. We monitored the radio for departures out of both Chennault International and Lake Charles Regional, hearing nothing leaving out of the first but there were two out of the second;they seemed to be south of us far enough where we didn’t see them. We continued west, paralleling I-10 toward Beaumont. The lighting of that time of day, our lower altitude, light traffic, and me flying from the right seat let me observe that highway through the city in a way I never had. I saw all the places I knew from my travels along it as I headed to and from Alabama both during family visits and my volunteer work on the Tomcat.

After we passed over Beaumont (KBMT), we turned south-southwest toward Chambers County (T00), our last checkpoint before hitting the Houston area. I made sure I knew where the two thousand foot radio towers were and kept us above them; as we passed over Chambers County, I used the sectional on my iPad to review Houston’s Class B floor configurations to make sure I wouldn’t fly into them while still holding us as high as I dared over Galveston Bay to keep engine out glide capability to its northern shoreline. As we approached the Bay’s northwestern corner, I descended us down to 1700 feet to get under the Class B floor over La Porte and Clear Lake.
galvestonbay
Over Chambers County and heading into Galveston Bay

Once we had passed the Kemah restaurant cluster guarding the entrance to Clear Lake, I descended to 1300 feet and turned us west, passing just south of JSC and Webster. Staying south of NASA Road 1 will always keep you out of Ellington’s Class D airspace, so I obeyed that until just east of Polly Ranch and had Pearland in sight. The Pearland ASOS advised us that the winds were favoring runway 14, so I flew us into downwind, slowing to my normal pattern speed of 75 knots, before pulling the throttle back abeam my landing point, dropping the flaps to 15, and then making a successful if a bit firm landing on that runway.
ffr14lvj
A moment before touch down on Runway 14 at KLVJ

CONCLUSION

Somehow, it all seemed anti-climactic. There’s no way you can tell when whether you had any impact with the kids at all, especially when you live so far away and probably won’t see them again. All you can do is hope you made a positive…and, if you are lucky, inspirational…impact on some kid you talked to who never realized that aviation (or manned spaceflight) could be theirs…that it wasn’t something just for the rich and famous. There are ways to get there even if you don’t grow up in a household of advantage, and I am an example of that, though I was not subject to the additional difficulties that often arise because of one’s race. My family didn’t have the money to support me learning to fly or going to college, and things did not go well for the only other person in my family who tried to go into aviation. Still, I am grateful I had his example so I knew how not to let adversity drag you down all the way when I stumbled into it during my own aviation pursuits. You gotta keep pressing on and make the lemonade you can. I persevered, and while I didn’t get to where I wanted to go I got to places I would not have anticipated and were, in some ways, better for me as a human being. It led to quite a career, one that made me very happy and showed me just how talented I was. Love at its best…

About six weeks or so after Guillermo and I made this trip, Russell Lewey sent me a very nice card that included a note written by one of the students. She thanked me for traveling so far to teach her about airplanes and told me how much it meant to her to see one up close. That single note says that it was worth doing; and I can tell you I would not hesitate to do it again and again, as long as I have the chance. Whether it is her that presses on into aviation or spaceflight or one of her compatriots, I can’t say. I can only hope.

For there was someone who inspired me, though I am not sure he ever realized it. He wasn’t a pilot or an engineer but an Opelika High School social studies teacher named Andrew Lisman. When all my other classmates just thought I was weird, he always seemed eager to stand me up on Current Events day and explain to the class, with my model spacecrafts in hand, what was going on with any ongoing US manned spaceflight mission. It was the heyday of Apollo, so there were several. They were enough to form my only real validation of my love for flight; and to this day I am extremely grateful for it…and to him. Without it, it’s hard to say whether I might have ever pushed forward to chase my dreams; and they are what led me and still lead me to take flight in whatever way I can.

Flying for FlyQuest (Part 2 of 3)

Guillermo and I spent the night in a La Quinta in Madison and met the next morning for its complimentary breakfast before heading out for the FlyQuest shop over at Hunstville International. I was looking forward to meeting Russell Lewey for the first time as we plugged in the destination into the iPhone and started toward the airport. The iPhone GPS decided that the shortest route was one that took us into a cargo gate; we were staring at a TSA shack we knew we weren’t going to get past when we figured it out. I turned us around and headed us toward the main gate to the airport when Russell called, and he confirmed I was now headed the right way and told us how to get there. A few minutes later, we had wound our way past the main terminal and found the FlyQuest shop, which was collocated with a new flight school, Revolution Aviation.

Inside the door, we met Russell and the manager of the flight school, Chris Burns. Russell led us back to the simulator. It is a 6 degree of freedom motion base simulator by Precision Flight. Russell told us they had acquired it as a prototype, even though the company now had them in production. Saying it was ready go, he opened the rear door and we stepped up into the cab. Guillermo went first; he was going to fly left seat as the pilot in command. I dropped into the right seat to find that only the left had the controls; but since the worst that could happen was we could crash the sim, I was okay with it. Russell was at the instructor’s station which was outside the cab; we talked back and forth via headset. We were sitting on the long runway, i.e., the twelve thousand feet of runway 36 Left in a simulated Cessna 172. Since Guillermo had only flown airplanes with a Rotax engine, I talked him through the start up sequence. The engine sprang to life. No takeoff checks necessary; we pushed the throttle forward and the airplane followed. We rotated at about 50 knots, and we were off!

We continued pressing north, climbing to 6500. Once there, we leveled off and then I told Guillermo to hold his altitude and pull the throttle to idle. We got slower, and slower, and slower, creeping up on a stall.

“Keep it going….keep it going!” I urged. “All the way into the stall!”

The stall horn started going off. We felt the airplane shudder.

“Keep the stick back. NOW! FULL LEFT RUDDER!”

The nose dropped, the airplane rolled and whipped to the left, corkscrewing the nose straight down. I noted what the ground looked like and what was directly “up” as we twiseted left and around.

“One…two….three! Neutral stick! Right rudder!”

The airplane came to an abrupt stop, fishtailing a little back and forth as Guillermo figured out how much rudder he needed.

“Look at your airspeed! We’re really FAST; start pulling back on the stick but NOT TOO FAST!”

The nose came up fairly quickly. Guillermo stopped it at the horizon.

“Power back on,” I said. “Take us to cruise!”

“Nice job, “ I continued.

“Let’s do that again!” Guillermo exclaimed.

And we did! Spin after spin, some right, some left; and one that started left, went flat, bobbed, and broke right as Guillermo danced on the rudders, reversing them to see what it would do.

With only a few minutes to go, I broke off the spin training and Russell reset us into the pattern for Cullman, a small airport south of HSV. We made three practice runs, working to get consistent stabilized approaches and, hopefully, a simulated landing. Unfortunately, we didn’t get there; Guillermo had a tendency to hang high so getting to a landing could only be done if one was a Kamikaze. That was something we were going to have to fix in the real world. The hour of time we had paid for was up.

We chatted for a few minutes about the session, confirmed the schedule for the rest of the day, and then left while Russell took a young man back to the simulator. Guillermo went back to our rental car, made our way out of the airport to I-565 East, flying down the highway to Exit 15, the exit to the US Space and Rocket Center. At the top of the exit, I turned right toward the Center and immediately left to take us down to Aviation Challenge. Left turn, right turn, and one hill and down another until the road was intersected by a fence separating us from the sharp, finned form of the F-14 Tomcat standing beyond.

After parking the car, we made our way through the gate at the sidewalk, and I walked Guillermo around my F-14 as he photographed her using his phone.
tomcatussrc
A picture of the F-14 as she sits at Aviation Challenge.

When I had known the Tomcat in our youth, she had been the Navy’s premiere fighter/interceptor, launching off carrier decks, intercepting real bogies inbound toward the task force as it sailed over the world’s oceans; shooting missiles at drones; rolling in for simulated kills against everything from A-4’s to F-4’s, F-5’s, other F-14’s and even Omani Jaguar’s; and jinking away from simulated missiles. She was quiet now, standing there kneeled for the catapult with her wings swept back, something you’d never really see. She looked in really good shape. Very little dirt covered her paint still shiny from the refresh we had given her a year before. I didn’t think she would look that good. The only thing I noticed untoward was a single bird’s nest stuffed into a wheel well. You had to admire a bird that could pull that off since we had closed up most of the Tomcat’s landing gear doors to try to keep the critters out. It was just another lesson on how resilient and resourceful life really is.

To see the rest of Aviation Challenge, Guillermo and I walked around the building used for classes, simulations, and bunk rooms to the stands, hoists, and aircraft hulls positioned in the water egress training area. I explained the purpose of the the “helo dunker” (a helicopter version of the Dilbert Dunker) and the water slide (parachute harness egress training) before taking him to a nearby F-4 whose history included a MIG kill during the Vietnam War. Next we visited a Navy A-7, an Air Force F-111 and F-16, a Navy Seasprite helicopter, a T-38, and a MIG-17 before making our way back past the F-14, said goodbye, and returned to our car in the parking lot.

After a lunch at Chick-Fil-A, we returned to our hotel for a break and to get ready for the afternoon. I was really looking forward to delivering a presentation on Aircraft Systems to FlyQuest students from Mae Jemison High School. Afterwards, we were going to let the kids go out to the CTSW to see and touch an actual aircraft, though you gotta’ be careful they don’t touch too much…!

For a little “show”, I put on what I call my “Fancy Bag”, a royal blue and Navy blue flight suit styled somewhat like a uniform from Star Trek: The Next Generation. It sports a set of gold NFO wings on the left chest, a Flight Design CTSW patch I designed and had made on the right one, a 1000 Hour Tomcat patch on the left shoulder, and another CTSW-centric patch on the right. I combined that with a black and red “VF-51 Tomcat Project” ball cap whose logo I also designed, and then met Guillermo downstairs in the La Quinta where we were staying before driving back out to Huntsville Executive. When we arrived, Russell was already there with his wife Diane and set up in the airport’s conference room. After we all met each other, Russell and I chatted about how I was going to present; I had brought a MacBook Pro I was going to use if needed but Russell had one ready. I practiced with the pointer/slide controller, making sure I knew how to make my slideshow work as we heard the school bus containing my audience pull up in front of the building.

The kids and their advisers piled out of the bus and into the room, filling it with noise and activity. Russell had mentioned it was an unusual class in that the students were mostly female. They were also mostly African-American and from Mae Jemison High Schoo. Many if not all of its members were from the Air Force Junior Reserve Officers Training Corp (ROTC) there. While I was ex-Navy, I had been in Army JROTC while at Opelika High School few hundred miles south; in addition to an interest in aviation, I had some Alabama high school experiences in common with them.

Russell had a big bag of candy at the top of the table, motivation to keep the young crowd engaged and motivated. I sat down in chairs along the side of the long table that formed the center of the room as the kids filled it in on all sides except for the very front where Russell stood. Russell reminded them what we were her to cover and tossed candy to the students who successfully answered his questions. He introduced me and I moved to the front of the room, told the kids a little bit about myself, and then proceeded into the presentation.

Edward Tufte makes his living talking about how using PowerPoint makes people stupid; and though I had practiced with the material, I quickly learned that when you are talking to kids, that’s close to the truth. A more accurate description of what happens is the kids find it BORING, no matter how enthusiastic the presenter is. And I was. Russell jumped in to rescue me with candy and a Jeopardy game show approach that kept things alive until we had covered the parts of an airplane and what they do. Then, the adult advisors and Russell led the group outside onto the ramp, stressing how important it was to both stay together and pay attention to taxiing airplanes.

Out at the CTSW, we split the kids into two groups with Russell taking one and me the other.
russell_empenange
Russell Lewey and his kids at the CTSW.

We opened the aircraft’s doors to let the kids see inside the cockpit, and I started at the nose of the aircraft showing the kids the aircraft systems we had just discussed, going down the aircraft’s left side as Russell and his group started at the tail and went up the right.
andy_wing
Yours truly with my group of kids at the front of the aircraft;

The kids were surprised the airplane was so small and to learn that it had an emergency parachute that lower could it to the ground. Even as small as it was, I pointed out, Guillermo and I could take off from KMDQ and be in Houston only 6 hours later while costing only 30 gallons of gas.

For many of these kids, it was the first time they had been that close to any airplane. One young woman was shocked to discover she didn’t need an academic degree to become a civilian pilot; it just took learning the skills and passing written and flight tests. I could see her wheels turning as she pondered the possibilities she might not have known were there.
student_cockpit
One of the students looking into the cockpit of the CTSW.

After a little over a half hour out at the airplane, we gathered as a group just outside the FBO and Russell’s and the teachers took photos of us all. Then, we returned into the building while the kids piled back onto their bus.

I spent a few minutes thanking Russell for rescuing me and discussing how to approach kids in that age group. Russell felt I had done fine, though I wasn’t sure of that since I had seen a kid or two nodding off. Nothing like coming in from out of town and leaving with a reputation intact. I usually put at least twice that many adults asleep….

That evening, Guillermo, Russell, Matt Zwack, and I met at a local restaurant Russell had suggested named “1892 East”. (See http://www.1892east.com.). It was a great little place with good food and ambiance. Matt was a friend of mine, a fellow volunteer on the Tomcat Project as well as a fellow pilot and aerospace engineer, and a colleague in manned space flight. We all listened as Russell shared with us many of his experiences as an Air Force B-52 and instructor pilot. We talked about Flyquest since Matt was coming to talk to the same kids in a few weeks to share his experiences as an aerospace engineer. We were joined briefly by Ed Steward, the Director of Exhibits at USSRC, who couldn’t join us for dinner but take a few minutes to say “hello” and let us talk about the Tomcat as well as the other space related projects I was curious about. For dinner, I had a pan roasted North Carolina stuffed trout, with fingerling potatoes, and broccoli. Nothing like a good dinner to top off the evening talking with good men and fellow pilots. A great way to top off a very satisfying day.

Flying for FlyQuest (Part 1 of 3)

One of my great passions right now is to inspire kids to get involved with aviation and space. I’ve done quite a few Young Eagle flights, and the Experimental Aircraft Association’s dedication to that program is the prime reason I stay a member since I’m not building an airplane and don’t have any immediate plans to do so. I’ve looked into getting involved with other programs in Houston; but, so far, having found anything I could participate in as a Light Sport instructor. As I’ve said before in this blog, the aviation education community is missing opportunities to get and keep kids engaged by not getting them into their Light Sport rating vice soloing them as Private Pilot students and then dropping them off. I’m working on getting an Advanced Ground Instructor (AGI) rating to see what doors it might open; and I’m always looking for more opportunities to engage youth with aviation and space in some way. Sadly, the opportunities in Houston seem a bit limited, even though it’s Space City.

For about a two-year period, I was the volunteer leader of a team restoring a F-14A on display at the US Space and Rocket Center in Huntsville, Alabama. I was shuffling from my Rocket City to the other in the CTSW, flying into Huntsville Executive Airport because of their great hospitality and absence of landing fees. The particular F-14 we were working on had been in my fighter squadron, the Screaming Eagles of VF-51, and I had flown in her 28 times as a Radar Intercept Officer (26 times in VF-51 and twice in VF-124), mostly while we were on an “around-the-world cruise” aboard the USS Carl Vinson in 1983. While I was in Huntsville on one of my trips, I learned about FlyQuest, an educational non-profit whose goal was to bring kids into the aviation fold and enhance STEM (Science, technology, and math) education. They conducted programs that engaged homeschoolers, middle school, and high schoolers and sponsored or participated in local events. I don’t remember now how I first heard about the; but, as I looked into them, I thought that what they were doing was the best thing since sliced bread, and I wanted in. My first attempt to engage with them was during a Women In Aviation event; one of the volunteers on the Tomcat team, Clarissa, and I planned to attend to encourage anyone interested to join us on the Tomcat team. I printed up brochures and flyers and Clarissa made a large and wonderful photo collage. I planned to fly the CTSW up not only as personal transportation but to throw in with a Young Eagle rally being conducted by EAA Chapter 190 in conjunction with the event. Unfortunately, snow and ice clobbered the runway at KMDQ on day before the event when I needed to fly in; and despite several conversations with the FBO on the phone, I couldn’t get any solid estimates for when the runway would be usable. Runways at KHSV were in use, but there were still NOTAMS about ice on the taxiways. Staring at those conditions, I just couldn’t see committing to that trip in the CT and the prospect of a 13 hour drive solo one way wasn’t attractive either, so I backed out.

I tried later to meet up with them at an AOPA fly-in up in Tennessee; but weather once again became an issue and I couldn’t figure out a good plan to work around it. I didn’t see an opportunity to get engaged with them again until the summer of 2016 when they asked for volunteers to teach classes in an aviation summer camp. I signed up to teach a class in aerodynamics and was really looking forward to it, especially after discovering some issues with material they had borrowed from a Rod Machado text that I wanted to correct (See my blog about “Only One Form of Lift”). But, sometimes, life has its own plans; my mother-in-law’s health started rapidly deteriorating and my wife was diagnosed with a life-threatening form of bladder cancer, and I wound up with more important priorities. A few months later, I learned they were going to hold some afternoon high school classes and inquired about teaching the aerodynamics class, but the aero class was taken and the classes that were open required me to move a doctor’s appointment that was ridiculously hard to get. I figured I was done. But Providence stepped in. A few weeks before that class, the doctor’s office called and asked me to reschedule; so, after checking with my wife about whether she was okay with the trip (and getting a “yes”), I immediately contacted FlyQuest’s Educational Director, Russell Lewey, and asked if there were still classes open and could I come up? He was happy to oblige. He had an aircraft systems class open that was being taught at KMDQ; and, if I flew up in the CTSW, the kids could go out and see the systems we were teaching them about. I signed up with glee! Now, all I needed was for the Gods of Weather to cooperate, as fickle as they are.

As the time approached, the Gods smiled, and it was looking like a flight in the CTSW was going to be possible. Connie would not be going with me, so I had an open seat in CT and a Light Sport student whose dream was and is to make the long cross-country from Houston to South Carolina. I invited him to accompany me. Guillermo was thrilled to go, so I told him to pick two legs of the four leg trip to flight plan and fly using only the Sectional (How archaic!); we would fly the other two legs using GPS and routes I already had put together. The overall plan would be to fly from Pearland (KLVJ) to McComb, Mississippi (KMCB) and from there to Huntsville Executive (KMDQ), about a six hour flight, and then return home using reverse legs a few days later.

Guillermo is an architect who does very detailed planning for a living, and his flight planning reflected it. I had never seen such details fleshed out of a flight plan since training in the Navy for low level missions. He did a very thorough, detailed job; but there were still some details to tweak and it would be difficult to sustain his approach once he was on the road. He had included reproductions of the sectionals cut and assembled into a booklet, great for handling in the cockpit but taking lots of printing and construction time, something you were not going to have sitting in an FBO and replanning your next leg due to weather. Additionally, he had used some Class D airfields as checkpoints, no sweat as long as you know you can fly over the top of them but something never guaranteed due to Light Sport rules (no overflight of a cloud layer that cuts off contact with the ground). I prefer to form plans that don’t have a high probability of being forced to change on the fly; so I pointed out to him that he would have to deviate or get permission to go through if the ceiling was lower than the top of the Class D. He moved his checkpoints to accommodate those comments, and I deemed us ready to go.

On the Tuesday morning of September 20th, we manned up under clear but hazy skies. The weather brief had said we’d have 10 miles visibility, but the haze and blazing morning sun cut effective visibility down to about half that once we were in the air. The winds were out of the east and would get higher the closer to Alabama we got, but we had something less than a ten knot headwind when we took off and headed east. I performed the takeoff on runway 14, climbed us out toward the southeast, then east, and leveled us off at 1500 feet AGL. I gave the airplane to Guillermo. Flying his flight plan, he cut us across Galveston Bay; and once we moved from under the 2000 foot floor to the 4000 foot Class B floor, he climbed us up to 3500 feet and leveled us off, heading us northeast toward Beaumont. Since were dependent on the sectional for navigation, I pressed Guillermo frequently to show me where we were, and he did an admirable job of putting us right where we needed to be and was always on top of it. His preflight prep really paid off.

ATIS broadcasts for Beaumont were still calling it clear; but as we pressed to the north of it while traveling east, I noticed an thickening band of clouds ahead at our altitude. It was a layer of cumulus clouds with bases right where we were and tops two thousand feet higher. While they weren’t impossible to get over, their coverage was going to make it difficult to wind our way through them, and I wasn’t ready to try to climb over them until I understood conditions beyond. The Lake Charles ATIS was also calling “clear”; but we could see clouds down to the coast and continuing east, and there were much larger build ups over the Gulf to our south. I pulled in the latest report for McComb using XM Satellite weather on our GPS display; it was saying the airport was clear with at least six miles viz. METARS only give you the conditions at the airport and only hint at what might be beyond, but I still felt there was a good chance what we were seeing would not last. It was a safer bet to go low, so I told Guillermo to drop down to three thousand and fly there.
gamntomccomb
The view at 3000 with Guillermo flying to McComb

The clouds plagued us until we were passing Lafayette and then cleared out as I had hoped. The rest of the flight to McComb was in the clear with almost no clouds at all and only light chop that increased a bit as we approached the airport. Guillermo performed the descent to the forty-five degree entry for left traffic on runway 33; I took over a couple of miles from the airport and flew the downwind to a landing.
mccombfbo
The McComb Mississippi(KMCB)FBO

After fueling up and taking a bathroom and snack break, we manned up and departed northeast. Optimal winds were still a thirty-five hundred, so I leveled us there and then let the autopilot fly the GPS course. Guillermo was content to rest and look around.
ottoflying
“Otto” Flying toward KMCB.

However, as we approached Alabama, the turbulence began to increase until I couldn’t stand the dives and climbs the autopilot was doing and I took over for the rest of the trip. The closer we got to Huntsville, the more headwinds and turbulence increased. I was throttled up to handle the headwinds; and, at about an hour out of Huntsville near Jefferson County, I was having trouble telling visually how much fuel we had left. While I knew by fuel burn and time we probably had enough to get there without landing (and that when you’re bouncing around, fuel can appear to hide in the wings), I decided to land at Walker County to check it out. (Frankly, I get curious about airports I often fly over and my curiosity makes me want to land just to check them out.) I aborted the flight as we flew past Waklker County airport, teardropping into a left downwind for runway 9, and then performing a flaps up landing with the windsock standing out to the right as I taxied over to the fuel pumps to shut down. Once the airplane was stopped, not rocking, and level on thee ground, I could see we did have the fuel to get there with some reserve; but it only made sense to add some more fuel to increase our margin. We did, got back in, and taxied back out.

I let myself get faked out on the takeoff. I taxied out to 9 again as the ASOS was reporting calm and a limp windsock confirmed it. We did our takeoff checks and, since the winds seemed to have died down, I dropped the flaps to 15 and started the takeoff roll, rotating at a calm wind speed of 42 knots. As soon as the nosewheel came off the ground, the airplane started hard drifting right; I countered with more left rudder and got us airborne inputting a hard left crab as we passed the windsock standing out to the right again. Lesson learned. With the flaps down at 15 and the nose in the air, the airplane’s ability to counter drift ain’t very good; keep it on the ground until a slightly higher speed and then pop her off like I know to do.
flubbedtakeoff
What a Flubbed Crosswind Takeoff at Walker County Looks Like!

After bouncing through the air for about another twenty minutes, I called Huntsville approach about 25 miles out. They surprised me by clearing me direct to KMDQ at 3500 feet. From where we were, that would mean a direct overflight of Huntsville International just slightly offset from the US Space and Rocket Center and its full-scale Saturn V mock-up. Acknowledging the call, I turned us on heading as the turbulence started kicking us for all it was worth. I slowed us down to Va (98 knots) to keep my airplane in one piece. Once, the airplane dropped so violently we were sure the earth had to have moved; without seatbelts, we would have smashed our heads into the ceiling. earhmoves
What it Looks Like When The Earth Moves While Flying

Holding on, we continued toward Huntsville Executive as I edged the course a few degrees west to make sure I didn’t knick a restricted area. I assumed it was “cold” since approach had said nothing to us, but I figured there was no reason to test it out.

We already had Huntsville Executive in sight. The winds were out of the north meaning a landing on runway three-six. We had a very gusty ten knots of crosswind as I aligned us with the runway centerline and visually picked up the VASI (Visual Approach Slope Indicator). I left the flaps up due to both the magnitude of the crosswind and its gustiness and came in a bit too fast, trying to get her settled down as we crossed the threshold. Trying too hard to get a smooth touchdown, I bobbled the airplane in pitch; on the third bobble, I had hit my personal safety criteria (three tries to get down), eaten up more runway than desired, so I cobbed the throttle to go around. I saw the linemen, who had come out on the ramp to show me where to park, throw their hands up in frustration as they heard the engine gun and saw me go. Nothing like the roar of the crowd..! And they weren’t even serving peanuts…

I flew a right downwind for three-six, making sure I got a good setup abeam, and then flew a right base and final to complete the landing with a solid thump. That was good enough. I taxied us down and off the runway and over to the parking spot where the linemen were waiting with our rental car, happy just to be where we needed to be safe and sound.shutdownkmdq
The CTSW shut down and empty at KMDQ. The FBO building can be seen out the right window.