Return from Missouri (Part 2)

From the author: I apologize for the delay and the disjointedness of posting this. I’ve been dealing with a family medical issue and thought I still needed to write the second half, knew it would take a while, had the AOPA issue jump up which I thought was quicker to deal with, and then realized this part was done and I just needed to post it.

There was sign next to the self-serve fuel pump I hadn’t seen before. It mentioned a “SUPERUNICOM” operating on the same frequency as the Common Traffic Advisory Frequency (CTAF), 122.8 for this airport. I had never seen or heard of it and, since I was focusing on getting the CT refueled, I didn’t take the time to read it. I fueled up for the next leg, and then met Connie inside the FBO. We sat down to a lunch of peanut butter crackers and Diet Coke while I pulled out the iPad and plotted a new course for our next leg.

Our next fueling stop was to be in Mount Pleasant, Texas. It’s an airfield we typically use as a fuel stop on the trip to Missouri and back from Houston. A single but very nice six thousand foot runway, great facilities, great people, and airplanes from the Commemorative Air Force. To get to it down the west side of the mountains, we still needed just a small jog further west, so I planned to fly southwest to Grove near Lake of the Cherokees before turning almost due south toward Texas.

The winds were strongly out of the southwest when we taxied out for takeoff on runway 19. Three clicks on the CTAF frequency (and not by us) triggered off an automated voice telling us the wind direction and velocity, our SUPERUNICOM at work. Once we were ready, I gunned her up the hill for 19 using no flaps because of the strong, gusty crosswinds, and we hit the top of the gradient about the same time I got to flying speed. We got airborne with a little hop before starting to climb away and turning right almost immediately. I climbed around the scattered clouds at speed driven again more by the oil temperature gauge than anything else. We leveled off a forty-five hundred feet for this leg; the winds were better there, the clouds were below us, and the ride was fairly smooth. To our left, the deck looked fairly solid, the cumulonimbus clouds were still there and quite tall, and I was very glad I had made the decision I did. As we flew over the ridgelines to the south we would have to cross, the clouds looked like they were lower than I had initially thought.

As we motored south past Sallisaw and Fort Smith under the clouds to our east, we saw a regional airliner cross several miles in front of us in a descending left turn. We watched him arc toward the cloud deck and then disappear beneath it as we moved toward skies that were turning milky. The visibility was dropping below us. At first, I thought it was mist; but there was a whiteness to it I couldn’t reconcile. As the puffy clouds moved past us below, one of them was as black as the side of a heavy thunderstorm, even though it was only a hundred feet tall and wide. Then, we were suddenly flying over a wildfire, the source of the white smoke that was filling the sky. There was no one or any equipment down there; it was burning in a solid east-west line. We pressed on south beyond it, and the sky quickly began to clear.

Soon, we were swinging past the snake-like curves of the Red River and entering our home state of Texas. We were still about thirty minutes away from Mount Pleasant, three hours flying time away from home, and a six to seven-hour drive if we were to switch to a car. It was just before two p.m. in the afternoon, the sun was blazing, and the clouds were building, fired up by moisture from the Gulf of Mexico still hundreds of miles away. The visibility was good but not unlimited; there seemed to be some haze in the distance. The cloud bases were moving up but they were also growing vertically; I knew there was a good chance that the next leg of the trip south toward Houston would have to be flown lower, both because of a slight change in heading and because of the building clouds. Both the NEXRAD satellite weather being displayed on our Garmin 496 and the view out the window said there were building cumulonimbus clouds just east of our route; once I got on the ground at Mount Pleasant, I’d take some time to recheck forecasts and take a more leisurely look at them for development and movement. With the long day, we could wait out any convective activity if needed; there was often a two to three hour window late in the day after the thunderstorms had died down when you could fly in, and that was just enough time to get to Houston from there. Since we were flying Light Sport rules, we would have to turn into a pumpkin shortly after sunset; if we couldn’t touch down at Pearland by then, Mount Pleasant would be our stop for the night.

We started picking up KOSA’s AWOS; winds were light and out of the south-southwest, meaning we would be heading for a straight in on runway 17. As we approached, I heard a Bonanza also coming in from the west; but he was much closer so I expected him to be on the ground by the time we got there. I slowly descended the airplane down to about two thousand feet AGL, and we bounced toward the city of Mount Pleasant which we could see through the haze. The confines of the airport and then the black strip of its runway slowly materialized, and I let down to the pattern altitude of 1400 feet to pick up the red and white lights of the 4 light PAPI. They were all white, so I pulled the power back and started slowing down to eighty knots so I could drop to fifteen degree flaps. There was just a little bit of gustiness in the winds, so I slowed down to sixty knots instead of a calm wind fifty-four and flew the glide slope on the PAPI using power until I made the runway and I touched her down.

Turning right onto taxiway Charlie, I called clear of the runway over the radio and headed us toward the FBO and the self-serve gas pumps to the north side. Pulling up to the pump, I went through the Shutdown checklist, pinning the BRS to keep it from being inadvertently fired, shutting down my electronics and then the engine before pulling the circuit breakers that act as a Master switch. We opened the doors and slid out, and Connie headed toward the FBO while I got out and headed to the pumps to get us gassed up before taking my break.

Unlike the day before when a low pressure system in the Gulf had pumped lines of thunderstorms up from the south, the cells I was seeing on the radar seemed to be moving very little and the coverage was isolated to small pockets we could fly around if needed. The forecasts were calling for a chance of thunderstorms until six p.m., but our route (for the moment) was clear. As Connie and I took another Coke and Cracker break, I told her it looked good for pressing on. We had the option of stopping for the night at Nacodoches if Houston got socked in; there was bed and breakfast there I was interested in checking out if the need arose. So, after getting refreshed and briefed, we climbed back into the CT and took off to the south.

The cloud bases were at about forty-five but the tops were up at about eight thousand and rising in the fiery sun, so I leveled off at thirty-five where it was about eighty degrees and infected with a bumpy ride. Turbulence usually forces me to hand fly the airplane especially with Connie aboard; I do a better job smoothing out the bumps than my simple autopilot which has no filters and climbs and dives like a Kamikaze in them. We flew south past Longview, Nacodoches, and Lufkin before driving just east of the large Class B ring surrounding Houston, watching the rain from numerous cells fall in misty sheets just east of us. I held our altitude until we were approaching the east side of Galveston Bay, before letting down to 2500 and finally 1500 feet to scoot under the floors of Houston’s Class B. Hugging the coastline on the north to give us some option other than ditching if we suffered an engine out, we made our way past La Porte and the restaurants at Kemah before turning west just south of Clear Lake. The familiar haunts of Johnson Space Center and Webster slid down our right side; we could see the large expanse of runways that are Ellington Field just beyond. I dialed in Pearland airport’s ASOS; the winds were favoring runway 14. We entered the pattern on a forty-five from the southeast, put the flaps down at fifteen on the downwind abeam, and landed, glad to be home.

When “Simpler” Becomes Dumb

I’ve always loved to teach. That love has led me to multiple places within the realm of aviation and aerospace, starting with being the nerdy kid standing in front of his high school government class with his models of Gemini and Apollo spacecraft, to being a NATOPS instructor in the F-14, an astronaut trainer at NASA’s Johnson Space Center for a decade, and a Light Sport Flight Instructor and blogger (writer) today. Through it all, I’ve always strived to make difficult technical subjects accurate and understandable to my audiences.

I’ve also seen and experienced the other end of the scale, i.e., instructors who made technical content more complex that it needed to be in an apparent scheme to demonstrate their mental superiority to students, and instructors who “simplified” the material to the point it became technically inaccurate. Both approaches are a form of arrogance or ignorance; take your pick.

I’m a personal fan of Einstein’s admonition that “everything should be as simple as it can be, but no simpler”. About two weeks ago, I was in Edward Tufte’s class on presenting technical data where he stated that “dumbing down is pandering”. How true! The assumption behind any “dumbing down” is that the audience is not smart enough to understand the technical material but the presenters are. This is often not the case. As a good friend of mine used to say: “You can’t give away what you don’t have”; and that applies to the understanding of a subject as well as other things.

The latest unfortunate example of something dumbed down to the point of being technically incorrect is the current iteration of AOPA’s “Essential Aerodynamics” presentation. Frankly, there is nothing essential at all about it; I do, in fact, steer my students away from it. You know something is dreadfully wrong with their approach when they state that the “wing pushes down on the air”, something that simply does not happen. I say that as an aerospace engineer who, as a student, plotted the pressure distributions about a subsonic wing section in a wind tunnel. Once you see the large low pressure area above the wing which grossly outclasses the high pressure areas underneath, you can intuitively tell that the most accurate explanation for what is happening is that the wing is sucked up from above.

So where did AOPA get the idea that the wing pushes down on the air? I don’t know, but it could have been from someone taught by a teacher who bought into a poorly thought out push by the American Association of Physics Teachers (AAPT) in the early 2000’s to replace Bernoulli’s law, which does a good job explaining how a wing generates lift, with Newton’s laws. The best rebuke to that approach was written and published in their magazine, “The Physics Teacher, Volume 40 in 2002 by aerodynamicist Charles N. Eastlake and entitled “An Aerodynamicist’s View of Lift, Bernoulli, and Newton”. (Ask Google to find it.) In it, he explains how both sets of principles apply and then goes through a technical explanation of the airfoil and how lift is created. He emphasizes that the choice of which set of use depends on which one is simpler to use. Indeed, we did use both approaches (i.e., Bernoulli’s and Newton’s) in various aerodynamic problems to find the answers. But since most kids and many pilots are not going to know how to use calculus, I personally believe that using Bernoulli’s explanation is not only correct but intuitively easier to understand. Additionally, you can use it in a classroom with very simple models (i.e., wing sections and simple wind tunnels) and do the calculations to show the forces involved, something that is difficult to do when using Newton’s laws to calculate the change in momentum of the airflow. When you talk to most people about Newton’s laws, and especially about Newton’s third, they intuitively understand it when talking about the application of thrust, since that’s what we’re nearly all familiar with. But start trying to relate that to the change in momentum of the total airflow field (the Newtonian approach), and they’ll scratch their heads or come up with some off-the-wall and technically incorrect explanation that the wing on a fixed wing aircraft pushes down on the air. Using Newton is a more intuitively easier approach to use and understand when talking about how propellers, jet engines, or rotor blades create force (thrust or lift), even though Bernoulli’s principle is alive and well and at work in them, too.

The AOPA presentation also decides that explaining aerodynamics using a wing is too hard, so they use a surfboard generating “lift” as it races through the water as their example. This is truly baffling, since it ignores one of the major rules of communication (common symbols and experiences between the transmitter and receiver) and totally fails to account for the force of buoyancy, which airplanes other than seaplanes don’t have for long if they land in the water. There simply was no reason for it; it did nothing to simplify the explanations of relative wind or angle of attack and brought the confusing environment of the water in the picture. (Daddy, how come an airplane doesn’t float in the air? My surfboard does.)

The presentation excuses its approach by telling viewers they don’t need to use the common approaches used for a century to explain aerodynamics because they were used for designing airplanes and it only needs to educate pilots (i.e., pilots are not smart enough to understand it). I didn’t think anything of that at first, until I saw where they were going. After that, I felt it was a red flag that it was all about to go off the track. True enough, pilots don’t need to know how to use calculus and integrals or the power and drag required values to calculate what to do next. But they do need to have a proper understanding of how a wing works and that needs to tie intuitively with what’s going on in the cockpit. I can use Bernoulli’s and angle of attack to make it clear what a stall is and that reducing the angle of attack to break the stall is all that counts; I’m not even sure how you could approach it when trying to explain it using Newton’s laws using change of momentum. In fact, I could easily see how someone not grasping it might think you need to use the wing to throw more air at the ground and pull the stick back HARDER. (The same action can result by teaching someone to believe in “impact lift”, which is not lift at all but drag acting in a vertical or near vertical direction.)

I did contact AOPA about this and forwarded them a copy of Eastlake’s article. In response, I got some mealy mouthed excuses about the difficulty of presenting complex technical material. The lesson has remained unchanged. Additionally, a few months after I set my response, “Flight Training” magazine, when promoting this presentation asked its readers “Newton or Bernoulli?”, stepping into the same nonsensical environment the AAPT had created. It’s not an either or choice, except when you’re trying to explain it. To do that correctly, you need to know what you’re talking about. And better care.

There’s a reason why NASA websites and the FAA’s “Handbook of Aeronautical Knowledge” uses Bernoulli for their basic explanation of aerodynamics. Too bad you don’t get WINGS credit for going there; you should.

Return From Missouri (Part 2 of 2)

There was sign next to the self-serve fuel pump I hadn’t seen before. It mentioned a “SUPERUNICOM” operating on the same frequency as the Common Traffic Advisory Frequency (CTAF), 122.8 for this airport. I had never seen or heard of it and, since I was focusing on getting the CT refueled, I didn’t take the time to read it. I fueled up for the next leg, and then met Connie inside the FBO. We sat down to a lunch of peanut butter crackers and Diet Coke while I pulled out the iPad and plotted a new course for our next leg.

Our next fueling stop was to be in Mount Pleasant, Texas. It’s an airfield we typically use as a fuel stop on the trip to Missouri and back from Houston. A single but very nice six thousand foot runway, great facilities, great people, and airplanes from the Commemorative Air Force. To get to it down the west side of the mountains, we still needed just a small jog further west, so I planned to fly southwest to Grove near Lake of the Cherokees before turning almost due south toward Texas.

The winds were strongly out of the southwest when we taxied out for takeoff on runway 19. Three clicks on the CTAF frequency (and not by us) triggered off an automated voice telling us the wind direction and velocity, our SUPERUNICOM at work. Once we were ready, I gunned her up the hill for 19 using no flaps because of the strong, gusty crosswinds, and we hit the top of the gradient about the same time I got to flying speed. We got airborne with a little hop before starting to climb away and turning right almost immediately. I climbed around the scattered clouds at speed driven again more by the oil temperature gauge than anything else. We leveled off a forty-five hundred feet for this leg; the winds were better there, the clouds were below us, and the ride was fairly smooth. To our left, the deck looked fairly solid, the cumulonimbus clouds were still there and quite tall, and I was very glad I had made the decision I did. As we flew over the ridgelines to the south we would have to cross, the clouds looked like they were lower than I had initially thought.

As we motored south past Sallisaw and Fort Smith under the clouds to our east, we saw a regional airliner cross several miles in front of us in a descending left turn. We watched him arc toward the cloud deck and then disappear beneath it as we moved toward skies that were turning milky. The visibility was dropping below us. At first, I thought it was mist; but there was a whiteness to it I couldn’t reconcile. As the puffy clouds moved past us below, one of them was as black as the side of a heavy thunderstorm, even though it was only a hundred feet tall and wide. Then, we were suddenly flying over a wildfire, the source of the white smoke that was filling the sky. There was no one or any equipment down there; it was burning in a solid east-west line. We pressed on south beyond it, and the sky quickly began to clear.

Soon, we were swinging past the snake-like curves of the Red River and entering our home state of Texas. We were still about thirty minutes away from Mount Pleasant, three hours flying time away from home, and a six to seven-hour drive if we were to switch to a car. It was just before two p.m. in the afternoon, the sun was blazing, and the clouds were building, fired up by moisture from the Gulf of Mexico still hundreds of miles away. The visibility was good but not unlimited; there seemed to be some haze in the distance. The cloud bases were moving up but they were also growing vertically; I knew there was a good chance that the next leg of the trip south toward Houston would have to be flown lower, both because of a slight change in heading and because of the building clouds. Both the NEXRAD satellite weather being displayed on our Garmin 496 and the view out the window said there were building cumulonimbus clouds just east of our route; once I got on the ground at Mount Pleasant, I’d take some time to recheck forecasts and take a more leisurely look at them for development and movement. With the long day, we could wait out any convective activity if needed; there was often a two to three hour window late in the day after the thunderstorms had died down when you could fly in, and that was just enough time to get to Houston from there. Since we were flying Light Sport rules, we would have to turn into a pumpkin shortly after sunset; if we couldn’t touch down at Pearland by then, Mount Pleasant would be our stop for the night.

We started picking up KOSA’s AWOS; winds were light and out of the south-southwest, meaning we would be heading for a straight in on runway 17. As we approached, I heard a Bonanza also coming in from the west; but he was much closer so I expected him to be on the ground by the time we got there. I slowly descended the airplane down to about two thousand feet AGL, and we bounced toward the city of Mount Pleasant which we could see through the haze. The confines of the airport and then the black strip of its runway slowly materialized, and I let down to the pattern altitude of 1400 feet to pick up the red and white lights of the 4 light PAPI. They were all white, so I pulled the power back and started slowing down to eighty knots so I could drop to fifteen degree flaps. There was just a little bit of gustiness in the winds, so I slowed down to sixty knots instead of a calm wind fifty-four and flew the glide slope on the PAPI using power until I made the runway and I touched her down.

Turning right onto taxiway Charlie, I called clear of the runway over the radio and headed us toward the FBO and the self-serve gas pumps to the north side. Pulling up to the pump, I went through the Shutdown checklist, pinning the BRS to keep it from being inadvertently fired, shutting down my electronics and then the engine before pulling the circuit breakers that act as a Master switch. We opened the doors and slid out, and Connie headed toward the FBO while I got out and headed to the pumps to get us gassed up before taking my break.

Conclusion

Unlike the day before when a low pressure system in the Gulf had pumped lines of thunderstorms up from the south, the cells I was seeing on the radar today seemed to be moving very little and the coverage was isolated to small pockets we could fly around if needed. The forecasts were calling for a chance of thunderstorms until six p.m., but our route (for the moment) was clear. As Connie and I took another Coke and Cracker break, I told her it looked good for pressing on. We had the option of stopping for the night at Nacodoches if Houston got socked in; there was bed and breakfast there I was interested in checking out if the need arose. So, after getting refreshed and briefed, we climbed back into the CT and taook off to the south.

The cloud bases were at about forty-five but the tops were up at about eight thousand and rising in the fiery sun, so I leveled off at thirty-five where it was about eighty degrees and infected with a bumpy ride. Turbulence usually forces me to hand fly the airplane especially with Connie aboard; I do a better job smoothing out the bumps than my simple autopilot which has no filters and climbs and dives like a Kamikaze in them. We flew south past Longview, Nacodoches, and Lufkin before driving just east of the large Class B ring surrounding Houston, watching the rain from numerous cells fall in misty sheets just east of us. I held our altitude until we were approaching the east side of Galveston Bay, before letting down to 2500 and finally 1500 feet to scoot under the floors of Houston’s Class B. Hugging the coastline on the north to give us some option other than ditching if we suffered an engine out, we made our way past La Porte and the restaurants at Kemah before turning west just south of Clear Lake. The familiar haunts of Johnson Space Center and Webster slid down our right side; we could see the large expanse of runways that are Ellington Field just beyond. I dialed in Pearland airport’s ASOS; the winds were favoring runway 14. We entered the pattern on a forty-five from the southeast, put the flaps down at fifteen on the downwind abeam, and landed, glad to be home.

Return From Missouri (Part 1 of 2)

It’s been a tough summer for us. Connie, my wife, discovered she had a serious medical condition and, in the middle of us dealing with that, her mother, who had been suffering from failing health, died. Her dad, a Marine World war II veteran and 95 years old, was still adjusting to the loss of his only partner (as we all were), and Connie felt she both wanted and needed to spend some more time with him. The thought of driving that trip was too much for me; so we decided to fly the CTSW up over Labor Day weekend, when I had an extra day off. The weather for the trip looked pretty good for the trip up from Houston and it was; while it was too rough a ride for Connie down low, the bases of the scattered cumulus clouds were around five thousand, so I took us to 6500 feet where we found light headwinds and a smooth ride. We flew from Houston to Mt Pleasant, Texas (one of the most hospitable airports anywhere; I left my billfold there once and the airport manager flew it down to Conroe where I retrieved it with nothing lost.), and then on to Rogers at Bentonville Arkansas and finally to Kirksville, Missouri where we bedded the airplane down. We had originally scheduled our return for Labor Day; but we had known when we left that the weather might be problematic for a return. I got up early and started checking weather. The Terminal forecasts for Houston hobby were talking about thunderstorm activity but Convective SIGMET issuances were expected. The National Weather Service forecasts were talking about a system in the Gulf pumping bands of moisture up from the south…. thunderstorms and locally heavy rain were possible with the chance of rain was about 60%. It was still forecasted to be VFR outside the TRW activity, but when you see those kinds of rain chances in Houston you have to be concerned about whether you can work your way around even with a VFR forecast. The storms often move in bands south to north; and, if you’re coming down from the north, you’ll be forced to make her large deviations or divert to avoid them. I was certain from the forecasts we could get to Mount Pleasant before we ran into anything and maybe Nacogdoches if we were lucky, but I told Connie the odds were good we would have to spend the night north of Houston and scoot in the next morning. She didn’t want to “stage” an arrival; and, since our whole point in making the trip was to give her the most time possible with her dad, I made the decision to delay a day when the forecasts looked better.

“Better” does not mean perfect. No matter which day we went home, winds were going to be a big issue through Missouri. On the surface they were out of the south to southwest at sixteen gusting to 24, forecasted to be one knot below the recommended operating limit on the surface for the CT. (I had operated the CT in winds up to about 22 kt gusts, and the airplane buffeted around on the ground but was very manageable at zero or negative six flap settings.) Crosswinds were not going to be a big problem, but headwinds were and I was concerned turbulence might be. At three thousand, winds were forecasted to be out of the southwest at thirty knots plus, which would take a big chunk out of the CT’s 112 knot no-wind cruise speed. The winds actually got better as you went higher; forecasted winds at 6500 were down to 25 knots or so. That made the big question: could we get there or would the cloud decks force us below? Sometimes, the Gods of Class E airspace and Light Sport rules would force you to descend because the cumulus clouds would be building so high it was not possible or practical to go over them. So, down you’d go to maintain adequate ground contact…even with a perfectly functioning moving map GPS…into a turbulent ride. All we could do was get going and see where it led.

We took off from Kirksville’s runway one eight at about eight-thirty in the morning. The winds were blowing almost straight down the runway at ten knots, so we got off fast and were climbing right away into wind getting higher fast. By the time I was climbing through three thousand feet, the GPS groundspeed was showing only 25 knots, a number I had never seen before on my GPS even when playing with slow flight in a headwind. (Best rate…which I was climbing at…was 78.) I kept her climbing, using a cruise climb set more by my engine oil temperature than anything on the airspeed indicator. We slowly made our way up to 6500 feet, where I nosed her over, popped the flaps into their minus six degree, full-up position, and let the engine accelerate us to cruise. Our ground speed clocked up to 87 knots, exactly the 25 knot headwind component we were expecting. Thankfully, the ride was smooth, so I clicked on the autopilot and let it track the course in our GPS while I followed our progress on my iPad, tracking my emergency landing fields as we flew past them. Even when we were out of range of any, we were still in good shape; below; the green farm fields were flat and separated by crisscrossing, long dirt and paved roads, any of which would do to land the small CT on if her engine croaked.

We steered southwest, turning south just to the west of the huge expanse that was Whiteman AFB some ten miles or so away. We picked up some knots with the turn; our groundspeed climbing up to 93 knots. We were now running a few knots ahead of the flight plan, making me feel a little better about not having any problems getting there. Until I used XM satellite weather to pull down the latest METAR. Our destination was the Class D airfield at Rogers, Arkansas, the home of the Walmart FBO. The METAR reported the field was broken at 2700 feet, eight hundred feet lower than the forecast had predicted. While that was plenty for us to get in, it was below the three thousand feet I use for flight through that area. Rogers is at the north end of a mountain bowl full of airfields that included North Arkansas Regional, Springdale, Fayetteville, and Fort Smith. To get out, we had to cross a ridgeline south of Fort Smith that jutted up to 2700 feet MSL, leaving us 1400 feet to go over it. While that was workable, it was not desirable, and the winds over it would more than likely make it a jolting ride.

As we approached Monnet, Misssouri, I could see the broken layer ahead, an ever thickening lake of cumulus clouds only three or four hundred feet thick. It went as far south as I could see, completely covering the mountains I knew we were approaching. What really got my attention was a cluster of towering cumulonimbus clouds slightly off to the east, signaling to me that possible rain and even thunderstorm development that could happen here could be an issue. I was very concerned that the ceiling and developing weather could keep us trapped in the valley for the afternoon, delaying us to the point of not making it to Houston today. I started looking at the iPad, which had our current position displayed on a sectional, for possible divert fields. Joplin was the closest and had the best facilities, but I wanted something both further south and east to reduce fuel consumption on the next leg and give us some room to scoot down the mountain range on the east side. I checked the information for Neosho; it was in a better location and had a city run FBO with self-service 100 low lead. At that exact moment, my wife, seeing the same things out the window that was concerning me, said something about a divert. Disengaging the autopilot, I pointed the airplane at Neosho and told her we were headed there, rather than heading into an area where I had doubts that we could proceed on when we wanted.

We tracked past Joplin and as we approached Neosho, I throttled back a bit to begin a descent. The ride roughened considerably as we descended past Granby, angling toward Neosho and the single north/south runway of its airport beyond. I dropped us down to about two thousand feet, scooting beneath the dotted clouds, as I angled us right to align with the runway for a very long straight-in. Connie spotted an aircraft on our right side and low; it took me a minute to find it, thought it was a twin at first but realized it was a crop duster as I got a better look. He seemed to be slowly angling away from us even further right; I saw him turn across a highway and seemingly head toward a field I assumed he was going to work, so I told Connie to keep him in sight and let me know if he headed our way. I continued toward the runway looking for other traffic and making a couple of radio calls marking our position and our intentions, when Connie let me know he had turned and was headed toward the same runway we were. I picked him up and, sure enough, he seemed to be flying a lot faster and was bee-lining toward the approach end of the runway, seeming oblivious to our presence and the radio calls I was making.

We were approaching runway one-nine with a lot of turbulence and a gusty, ten knot crosswind. The crop duster was about a half mile in front of us, touching down on a slanted runway that looked like it was running up a cliff before folding over and running flat, hiding its far end. Connie thought we needed to wave it off, that the crop duster was going to turn around and back taxi, but I told her I was continuing, confident there was a turn off at the end of the runway if not before. The airplane did turn off before getting to the end, just as I touched down a little past the first third of the runway and about half way up the climbing hill.

We turned left just north of the FBO, taxiing toward the gas pump we could see and past the crop duster and its pilot, who was exiting the airplane. I shut the CT’s engine down, and we opened the airplane’s gull wing doors to the hot air the gusty wind was circulating.

“Hot as hell, isn’t it?” the crop duster pilot said, walking past us and wiping his brow.

“It sure is,” I agreed. Meanwhile, Connie exited the airplane to head for the FBO, its air conditioning, its vending machines, and its bathroom.

Only One Form of Lift

I was reviewing a presentation on aerodynamics for a great aviation educational non-profit (FlyQuest in Huntsville, AL) when I came across a slide using a page out of Rod Machos’ Private Pilot Handbook that discusses lift generation. It said there were two forms of lift. One was due to impact pressure and one was due to low pressure over the top of the wing. Since I have been recommending Machado’s Light Sport Handbook to several of my students, I thought I better check to see if that explanation had been carried across there, and I discovered it had. I totally disagree with this description. What he calls “impact lift” is really drag acting in a vertical direction. There is only one form of lift,and it’s created by the Bernoulli effect and a little ditty called “circulation”.

Let’s start at the beginning.

Newton and Bernoulli can be called the kings of aerodynamics, though there are other scientists whose discoveries also play a very important role. I’m going to center in on the biggest areas where each makes a contribution, i.e., the conservation of momentum and Bernoulli’s’ principle. I’m only going to to address subsonic aerodynamics since that’s where most educational efforts lie and the issue of discussing supersonic lift becomes much more complicated. In the subsonic regime, I maintain there is only one form of lift; further, I think it’s extremely problematic to teach beginning pilots that “impact pressure” is a form of lift since, in the worst case, it can cause a pilot to do the wrong thing. The importance of understanding lift in terms of its relationship to the wing’s critical angle of attack cannot be understated; if you’re stalled, you need to reduce the critical angle of attack to get the wing flying again, not increase it in the hope of using “impact pressure” to keep you airborne. Further, Machado’s reference to low pressure lift allowing flow greater than the actual engineered circumference of a wing is a reference to the effect of circulation, which is in play anytime a wing is producing lift. More on that in a minute.

Every text I used when learning aerodynamics (as an aerospace engineer) starts off with an explanation of the aerodynamic flow fields using Bernoulli’s principle. One of the first things you do as an early aero student is put a positively cambered wing section in a wind tunnel and then plot the pressure distribution around the wing. You wind up with a plot that looks like this:

presssured002
When you add up the positive pressure and negative pressure contributions, you find the the negative pressure contributions far exceed the positive; in other words, the wing is more accurately described as being sucked up from above rather than pushed up from below. This is very easy to see and explain when using Bernoulli’s principle and yields a practical and calculable result. The resultant force is what we call lift, the force acts through a point called the center of Pressure or CP. (This is opposed to Cp which is the coefficient of pressure, a dimensionless number engineers can plug into an equation and calculate the pressure at any point if they also have the air density and velocity. In the same manner, engineers define Cl (C sub L—can’t write that properly using this) as the coefficient of lift, a dimensionless number that describes the lifting force an airfoil section can generate that can be calculated in the same manner, using the airstream velocity and density).

Admittedly, when you look at the above diagram, you can see the free stream pressure at the nose of the airfoil has positive pressure. That can lead you to call that “impact pressure” and it is, but I can assure you it is never separated out and treated as a separate entity when calculating lift. In addition to the forces explained by using Bernoulli’s the movement of the airflow over the airfoil is influenced by a phenomena called “circulation”, which naturally occurs due to the presence of the airfoil in the flowfield. A good model of its effect can be made by spinning a cylinder in the direction of the airflow past the airfoil, and the velocities it induces (called the Magnus effect) along with the freestream velocities produces the overall flow field. (This helps explain why the airflow over the top of an airfoil moves faster than that underneath.)
Magnus

And, so now, you’ve got the story about how lift is generated for a 2 dimensional wing, i.e., a wing of infinite length. That is how engineers explain, understand, and examine the generation of lift due to an airfoil. But real airplanes have finite wings with a length and width. So what happens on them?

Well, we already saw that there is a high pressure area under the wing and a low pressure area on top. That high pressure air is going to move toward the low pressure; and at the wingtips, it then curls around over the top of the wing creating vortices. These vortices affect the flow field over the wing and create “downwash”. In the drawing below, the vector labeled “effective lift” is the lift before taking downwash into account; the lift vector after taking downwash into account instated slightly aft, and the force vector between the two shows the horizontal component of the real lift vector acting in a rearward direction, i.e., creating drag. That is induced drag. Induced drag is often termed the “drag due to lift”, and you can see why.
Ibnduceddrag

With this, you’ve got a pretty complete picture of how a wing generates lift. There is a lot more to it than I’ve put in this blog; but the reason I’ve done this is to try to capture a technically correct explanation of how an airfoil works. I’ve used “the Bernoulli” approach here because I think it’s the easiest to understand, and I could have used “the Newton” approach but I don’t think it’s as relevant to pilots. There is a lot of misconception and disinformation out there about how a wing works; and I’m seeing too many oversimplifications that are simply flat out wrong. (More than I’ve ever seen in my long flying and engineering career. I’ve discussed this more in two others blogs, i.e, “Fuzzy Aerodynamics” and “Flying a CTSW with Flat Plate Wings: Analyzing “Impact Lift””) I will caveat this discussion by saying that I have limited it to subsonic aerodynamics at low altitudes where most of us fly; all bets are off when talking high altitude and high Mach flight, which is a different horse indeed.

Regaining the Promise of Light Sport

The upcoming changes to the Light Sport rules (assuming the changes in NPRM Docket No. FAA-2016-6142: Notice No 16-02 go through; how’s that for a mouthful?) can do a great deal to restore some of the lost promise of Light Sport. I commented to the FAA on that NPRM and said (among other things) Light Sport’s great promise and its best purpose is to serve as a gateway to getting new people involved with aviation and allowing others who would normally be excluded to participate. It may not be what actually drove the FAA to establish the rating and the category (which primarily was motivated as a way to regulate two-place ultralights), but it is the purpose it can best serve and the vision that needs to be behind it now.

Like anything new introduced into an old system, it is to some, and more often to those with no experience with it, a threat. There seems to often be an assumption that Light Sport aircraft are somehow inferior, despite the fact that many of them can and do outperform the standard trainers that have been around for decades. (My CTSW at full gross has the same power to weight ratio as a 200HP Piper Arrow.) Anyone who’s flown a Light Sport in very gusty winds or crosswinds can testify that the stick and rudder skills are no less and are often more demanding than those of many general aviation aircraft. (One old airline pilot told me the bigger an airplane is, the easier it is to fly; I add, …and it does more damage if it gets way from you.) There is also a perception that because Light Sport is considered a “recreational” rating, it is not on the stairway to a career in aviation. It needs to be considered the first step; and it usually is not, even by flight schools that have a Light Sport aircraft in their inventories.

Worse, most non-profits geared around aerospace education and that perform flight training take students to solo in standard trainers aimed at the private pilot rating and drop them one–third to half-way to there. I have no doubt that getting a student pilot to solo does encourage them to continue; but I am unconvinced it improves student pilot completion rates if that’s all that happens. For many of those kids, often low income, solo is all they can do until they become adults. How many of them will still be so interested in flying a decade later? Think about what happens if…instead of dropping them at solo…you dropped them with a pilot’s rating? A student who solos in ten hours is only one quarter of the way toward his Private Pilot rating, but he could be half way to getting his Light Sport. A student with 15 total hours would be only 5 hours away from possibly getting his own pilot rating. If you invest 5 more hours and take them to their Light Sport rating, they can probably hobble together money to fly at least occasionally….and stay in the air.

Of course, the thing inhibiting this just as much as the lack of vision is the more practical problem of low availability of good Light Sport trainers and the high costs of the ones that are out there. I’m not talking about the cost of operation (low) but the cost of “buy in”, the overhead associated with insurance, the high cost and long downtimes of repairs (which drives the high cost of commercial insurance). There are more Flight Design CT’s in the United States than almost any other Light Sport airplane; yet, when we suffered a bird strike that punched a hole in our canopy, it took ten weeks and a total cost of $10K to get the canopy replaced. ($2K of that was due to transport costs to a repair site, costs I now consider unnecessary because I listened to someone who was supposed to know about the airplane’s airworthiness instead of trusting my own engineering instincts.) Paul Shuch recently told a similar story at an EAA webinar on near mid air-collisions when his canopy was fractured during evasive maneuvers. (He wound up shipping his canopy and frame back to the aircraft manufacturer overseas and lost 12 weeks.). When I first learned how much it was going to cost to get the canopy replaced, I thought the insurance company would balk, but the agent told me it was inline with other light sports.

When Light Sport was invented, folks were looking for the movement to bring the costs of flying down to the price point of automobiles. And they did…as long as you’re looking for a racecar thoroughbred and not the family SUV. (Or don’t mind competing with the cost of your house.) Instead, most manufacturers have driven the market toward glass cockpits and fuel injected engines whose costs and utility are truly questionable for a day VFR airplane with shrinking useful loads. What will drive the market upward isn’t the fascination with high technology (though that will always drive point sales) but more utility and lower costs of both purchase and repair. There’s still a lot of market to be had for those that go after it; otherwise, Light Sport aircraft of the ilk of the CT, the Remos, the Sportstar, or the RV-12 will remain a niche market, handicapping its full development.

All this can change. If we want our children and grandchildren to have their own opportunities to soar like we can, we need to make it happen.

This CFI-S is Taking Off!

If you’ve been reading my blog for any length of time (and I found out this past weekend I have at least one reader…and he’s not in my family!), then you know I’ve felt like the FAA, EAA, and AOPA have been disregarding Light Sport. In particular, the press for Third Class Medical Reform seemed to have buried two issues near and dear to my heart as a Light Sport Instructor. The biggest injustice was that dual instruction toward a light sport certificate given by a Light Sport instructor (Subpart K, Part 61) didn’t seem to count toward a private or recreational pilot certificate (and I say “seem” because that was the interpretation of an FAA legal office opinion not actually codified into law). This held the potential to handicap a CFI-S trying to get new students that knew they wanted to go on to a higher certificate and privileges. (It didn’t seem to impact us when we had our flight school going as about half our students were “new starts”.) It also wasn’t fair to the students; if they wanted to train in a particular Light Sport aircraft, why shouldn’t they be able to train with the instructor they wanted, especially if he/she had the most experience in that aircraft, without taking a penalty?

The other piece of the Part 61 regulations that was troublesome was the fact that a Light Sport instructor without any other pilot ratings couldn’t give the required instrument training for their student pilots to go solo cross-country as required by 61.93 (e)(12). The NPRM corrects this deficiency by allowing Light Sport instructors who wish to give that instruction to do so after getting one hour of ground instruction and three hours of flight instruction and a competency endorsement from a Subpart H instructor. The NPRM also allows the CFI-S who has the endorsement to act as “safety pilot” under these conditions, closing the other legal loophole created by today’s regs. (That said, I was convinced that the current regs allowed a CFI-S with at least a private pilot certificate rating to act as safety pilot in an LSA even using a “driver’s license medical. Ask me sometime and I’ll show you; but it’ still nice not to have any ambiguity left.)

As you might guess, I’m going to fully support this NPRM and hope you will, too. I do have one comment to make on the first part (the CFI-S training requirement) in that the rationale for training is that they assume the CFI-S has no instrument experience. I’m going to suggest that the training requirement as written is overkill for a CFI-S who holds private or commercial pilot certificates with an instrument rating and that a Subpart H instructor endorsement of competency should be adequate. I’d have no issue with an hour of ground and an hour of flight to get a refresher; my CFI and I did “hood” work as a normal part of me working up for my CFI-S. Why not, though, just let the Subpart H instructor decide what it’s going to take?

For me personally, the timing of all this could not be better. I’ve been moving toward getting more into instructing; I’m hoping to test out for my Advanced Ground Instructor rating in the next two months. I just had a chat with the folks over at Coastal Skies Flying Club about Light Sport in general, and they, like me, are interested in growing it. So, I’ll be joining up (a decision reinforced when I found out one of the pilots I flew with in VF-51…and my roommate on the Vinson cruise…is a member) and getting checked out in the Remos to start instructing there. Hope you’ll come join me! This’ll be fun!

Elephants in the Room: ATC Privatization

Since I live near Houston, I am directly impacted by the air traffic control system, whether I directly use the services or not. Houston has two interlocking sections of Class B airspace, one protecting Houston Hobby (which is only 8nm from my home airport at Pearland) and the other protecting Houston Intercontinental, also known as Bush. Additionally, I often have my airplane serviced up at the Denton, TX airport where a Flight Design approved mechanic resides; and, when I do, I use flight following from takeoff to landing to both speed up my trip (by avoiding a very large sidestep of Class B airspace around Dallas’ west side) and to keep it safer. I often travel to Huntsville AL for volunteer work primarily at the U.S. Space and Rocket Center and have a new grandson south of there and a granddaughter (on the way..three more weeks!) north of there in Fort Knox, Kentucky. I often use flight following on those trips as well, and nearly always use Class C services to get into Huntsville Executive. With only a few exceptions, I have found the air traffic controllers friendly and easy to work with and a great asset in protecting me and my aircraft. So, I have a stake in what happens to the air traffic control system; it directly affects my efficiency, my economies, and…most importantly…my safety.

The current FAA reauthorization bill has passed the Senate but is stalled in the House. It is being held hostage because the chairman of the Transportation Committee, Rep Bill Shuster, wants to hand over control of the ATC system to a private “non-profit” corporation. He says the FAA is not moving fast enough on Next Gen ATC improvements and, as we all know, private industry can always do things better than government (a line that never takes into account things like the big banks collapsing the economy, the big tobacco companies having to be reigned in to improve public health, or why we’re seeing all those millions of airbags in autos being recalled). While this whole thing smells like a dead fish to me, for reasons I’ll get into later, the thing I really love about the recent efforts to move the system to user fees or privatization is the total lack of safety studies that go along with them.

THE ATC SYSTEM IS PRIMARILY A SAFETY SYSTEM. SO, WHY DO WE NEVER SEE SAFETY STUDIES ADDRESSING THE INTEGRATED IMPACTS BEFORE WE START TRYING TO MESS WITH IT?

(And if government never does anything right, do we really want a piece of the government, i.e., the Congress, deciding what to do with ATC? Kind of a conundrum, isn’t it?)

Indeed, a report by the Government Accounting Office pointed out the risks and issues associated with the transition. The report, entitled “Federal Aviation Administration: Preliminary Observations of Potential Air Traffic Control Restructuring Transition Issues” can be found here. I’m going to center my discussion of it to the overall safety impact of the transition, whether as a result of the privatization or the imposition of user fees.
“Preliminary discussions with experts have raised several transition issues that would need to be considered when separating safety oversight from ATC operations, such as (1) challenges with delineating roles and responsibilities, (2) potential impacts to coordination, and (3) potential impacts to the remaining safety regulator.”

The FAA’s current structure allows integration of flight standards procedures and approval of new procedures, something that could be adversely affected by splitting off ATC. Even if it can be done, no work has been done to figure out how it can be done or the time necessary to make it work. (This needed to have been done as part of the process of preparing this legislation; the Transportation Committee could have asked for this instead of just trying to ram the bill down everyone’s throats.) Further: “according to experts, how decisions about safety criteria, standards, and processes (e.g., separation standards for runways) would be made and who should be involved in that decision-making process would need to be addressed. Some experts stated that a process will need to be put into place to address disagreements between the safety regulator and the ATC entity regarding safety decisions.”

(Not only that, but what are the legal aspects of pilots dealing with an ATC entity that is now a private corporation? If this change were to happen, it would take a Pilots Bill of Rights 3 to address them.)

Additionally, here’s what the report says about the impacts of user fees: “Currently an array of users access the U.S. airspace, and the costs of the system are paid by these users through a series of taxes and fees paid as described above. If a system of user fees were to replace the current financing structure, there may be differential effects of the new funding structure across these different users. As we previously noted, a transition issue identified through our preliminary discussions with experts is how any user fee structure might differentially affect varied users and, in turn, how this would impact the use of the airspace. For example, some of the experts we spoke with noted that, depending on how user fees are structured, it is possible that general and business aviation might see their contribution to the cost of ATC services rise and that this increase could reduce the use of the airspace by these users.”

(Might see their contribution rise? Might!? It’s a certainty…)

And, here, ladies and gentlemen, we see…or miss seeing..one of the elephants in the room, i.e., the one unexplored question that never gets asked when we hit this topic: What is the impact on general aviation safety when users avoid ATC system services, especially in airspace underneath the floors of Class B airspace that are already congested?

And there is another elephant: “In addition, another concern raised by experts during our interviews is that small and rural communities could be negatively affected by a restructured ATC. According to one expert whom we spoke to, rules need to be in place for the ATC entity to not restrict access so that only high value customers, such as commercial airlines are served; access should be maintained for small communities and other services, which are important but don’t make a lot of money.”

So, all this is being ignored while the current FAA reauthorization is being held up to try to shove it into it (and, btw, the GAO report said that privatizing ATC could DELAY Next Gen improvements, which contradicts Shuster’s reasoning for why it’s needed). I always look sideways at people trying to push things through in a hurry, because they’re usually trying to keep you from looking too closely at it. That, and the following report by Politico about Rep Bill Shuster’s personal ties to one of the prime organizations supporting this legislation, make it smell like a dead fish to me.

Read the reports before you let them force us to take this fish home. If it really is as smelly as I think, we might not ever get rid of it.

Runways, Hazard Avoidance, and Risk Management

On the first Saturday after a week of flooding, my wife and I manned up the CTSW for a one hour flight northwest to Brenham. A great hundred dollar burger restaurant named “The Southern Diner” hosts a 1950’s theme, complete with a sometimes seen pink Cadillac golf cart, always present waitresses in poodle skirts, and sometimes working juke box controls at the tables. In addition to being the first nice weather weekend since the flooding, it was spring, meaning there would be lots of flyers, motorcycle and car clubs, and tourists out to see how many bluebonnets might be pointing at the sky. Sure enough, when we got there, ramp space was getting tight but we found a place to park the CT on the ramp right at the entrance from the runway. There is always a crowd outside the FBO waiting for their seats underneath its awning, and I’m sure they thought the little CT pilot had lost it when I nosed it in and shut down facing the “wrong” way. While very nimble in the air, the CTSW is not so on the ground; its wide turning radius teaches you quickly that the best way to park is to face her in and then shut down, get out, push down on the tail, and spin her around on the mains.

The lunch was good and, though there were a few more bumps in the air than I had thought there would be, the flight was uneventful. Almost. As we flew the final approach to runway 14 at Pearland, a silver and yellow high wing taxied up to the hold short. Just before we crossed in front of it, the pilot called he was departing one four. The impatience of the call gave me a half second of pause before I got busy with landing my own airplane. We landed near the thousand foot markers and turned off at taxiway Bravo, which is roughly halfway down the four thousand, three hundred foot runway. As I started turning off the runway, my wife looked back. Obviously, she was also wondering where the impatient pilot was, too; she saw him airborne and climbing. He had taken off behind us while we were still on the runway.

There is no regulation preventing two aircraft from being on the runway at the same time at a non-towered field. (Yes, I have flown formation and do understand we are not talking about that case.) The question becomes what risk is involved in any particular operation. It also becomes a perfect example of the difference between using “hazard avoidance” or “risk management”.

I believe most pilots practice “hazard avoidance”, i.e., recognizing a hazard to the flight and then avoiding it if possible. For the pilot taking off, practicing “hazard avoidance” means waiting until the aircraft on the runway is completely clear before taking the runway. Doing so completely alleviates any risk to the other aircraft of some kind of aberration occurring during the takeoff run, making dealing with any emergency that could happen easier and more likely to have a good outcome for everyone involved. Using “risk management” means looking at what the risk might be (loss of control or systems failures like engine, flight control, landing gear, etc.), examining the outcome (collision, fire, injury or death) and then deciding whether to proceed based on likelihood. In this case, we assume the pilot figured he could be well above us by the time he crossed over us and the risk was acceptable. The problem I have with that, though, is that he was making a risk decision for BOTH of us. We’ll assume he at least thought it through enough to sidestep us as he went over. As I said in my earlier blog, the problem for most folks in estimating likelihood is that they are overconfident in their answer. It’s like running a stoplight; you get away with it until you don’t.

In prepping for this blog, I read through the latest runway incursion brochure from the FAA. It discusses runway incursions in the context of controlled field operations but says nothing about non-towered fields. Frankly, from what I’ve experienced, I’ve got more to worry about…especially with people pulling out in front of me on final (usually from being over-reliant on the radio for traffic control) at non-towered airfields than anywhere else. At fly-in’s or any kind of crowded aviation event, it may be difficult to avoid being on the runway at the same time as another aircraft and may seem like a time-waster when the runway is several thousand feet long. Just be sure you’re thinking about not only your safety but those you might endanger if things go wrong. Even if nothing bad happens, you also don’t want to be on the bad side of someone’s You Tube video or the FAA inspector who starts looking at you trying to figure out whether “careless”, “reckless” or both apply. Either of those will present arguments you are not going to win.