Gordon: Can you elaborate on what causes the air to go faster along the upper surface of the wing rather than the bottom? The explanation I usually hear that the air travelling along the top must move faster in order to meet the air travelling along the bottom doesn’t sound convincing. (why should the two arrive at the trailing edge of the wing at them same time?) If the story is too long, can you give a reference?
Eugene

The article on the small airplanes, personally is upsetting. I am no pilot, and I happen to stumble upon this article. However, i knew the people on that plane as I am a family member…and what you wrote was rude. You didn’t know these “rich” people and how charitable they were. The “tycoon” you speak of was a silent donater and a silent hero. If you did your research you would find that he was honored in the base of the Intrepid Sea Air Space Museum by thousands. I hope that you realize he was taking his daughter to the same highschool he went to, and she was very excited to be going there. The daughter, who survived if you researched this crash, also has read this article and was very disturbed by your assumptians about her lifestyle. The plane happened to be a friend’s that was offered as a ride because it was convenient. That event was life altering for that girl, and I hope you are happy with your analysis of rich people and your stereo-type. Bob, the pilot also happened to be a great guy, so maybe you should reconsider what you type and keep it on a professional analysis!

A few brief comments from an aerospace engineer:
1. The lift is produced by Bernoulli’s Law (total pressure (dynamic + static) remaining roughly constant), not Newton’s Third Law (action & reaction, how rockets work), which is a common misperception, and results from the differences in pressures between the upper (faster-flowing & so lesser static pressure) surface and the lower.
2. The wing (airfoil) can be either symmetric or asymmetric (cambered). The flow changes based on angle of attack.
3. The lift required increases in a turn based on the reciprocal of the cosine of the bank angle (e.g. 2 g’s are pulled at 60 degrees bank).
4. The FAA recently announced a program to (eventually) replace many non-precision approaches with “virtual” (so to speak) ILS approaches. Hopefully this will progress faster than many of the FAA’s other projects have.

A great item on flying safety! It doesn’t motivate my IFR training, but it sure accentuates the factors of weather, flying physics, and critical transitions between visual and instruments. I would propose that going to bigger or better airports gets dangerously close to suggesting that wealthy people fly commercial airlines when the weather is bad!

The comments on aerodynamics are interesting. The lift controversy marches on, thanks to our education system. I always give credit to Kutta, and a nice sharp trailing edge on the wing. Bernoulli is a minor-league guy who got the press.

Gregory: I’m not a pilot, but a former Air Force weather officer. We weather guys get exposed to a lot of trivia. Airplanes use two mechanisms to fly: (1) Bernoulli effect from the asymmetric wing and (2) Angle of attack. Different airplanes use these two mechanisms in differing degrees due to the design constraints of each aircraft and whatever the pilot is attempting (e.g., inverted flight). For example, a T-38 trainer (and presumably the F-5 figher equivalent of the same craft) has an extremely tiny and absolutely symmetric wing. It’s mounted on an axle so that the pilot can angle it up or down at will. This airplane flies completely on brute force, with no appeal to Bernoulli!

Civil aviation grew up on non-precision approaches but I believe most pilots fail to practise the circle-to-land maneuver that accompanies nearly every one of those approaches. The mental shift required to transition from inside the cockpit flying instruments to outside the cockpit flying visual references is challenging. Add to that challenge the probability that clouds are possibly wispy and you have the prospect of a pilot flying too low for a normal contact traffic pattern. In those conditions, some people try pylon turns. But low-level acrobatics don’t always result in smooth landings when part of this kind of a mix. That’s my experience over 3000 flying hours on six continents.

Doug: You’re probably a more experienced pilot than I, so I’m not going to presume to preach to you. But personally I limit myself to ILS approaches if the weather is remotely bad because I want the extra layer of redundancy afforded by ATC. If I were up in Alaska and the nearest ILS were 2 hours away and the ceiling was 1000′ I’d probably do the non-precision approach. But here in the crowded Northeast there is almost always an ILS within a 30-minute drive from my destination.

Hallo from Germany, Philip.

Thankyou for an article well written and understandable to the layman.

I’ve been teaching people to fly for over 20 years. Despite all modern technology, ILS,GPS, whatever, it is still pilot-error that kills the most.
And going-too-slow is the major one. Continued-flight-in-bad-weather is major for VFR pilots, some of whom RELY on a GPS they can barely interpret, in really marginal scud-running conditions.
Generally, the killer-disease is known here as “Get-Home-itis”

Stu Savory, CFII

Philip,

Many handheld GPS units store track information, but I have yet to see an IFR certified panel mounted GPS store that information.

Philip, You might want to clarify whether your condemnation is for all non-precision approaches or just the circle-to-land maneuver? Sure, I love an easy ILS (particularly with my GNS430 coupled to the S-Tec 60-2 autopilot through my GPSS interface), but my home field only has a GPS approach due to terrain. No ILS. I don’t consider that non-precision approach to be significantly more dangerous than the ILS at a nearby airport, >>>so long as I can land straight in -OR- the ceilings are such that I have to maneuver at less than VFR pattern altitude.<<< To my mind, there’s a discontinuity in the risk curve if I have to perform a circle-to-land at low altitude, but not just because the approach isn’t an ILS. And don’t forget that there are cirlce-to-land terminations for most ILSs as well, and those are (in my mind) even more dangerous, since they can often be done at even lower AGL altitudes.

The only time I’ve scared myself on an approach was on a straight-in ILS to minimums where I got distracted and lost the localizer needle completely at minimums. The first thing I saw through the fog was a hangar at 12 o’clock. Oops!