Top Letters And Comments, December 14, 2018


Fuel Strainer Lottery

A significant omission from Jeff Parnau’s very interesting article is the Decathlon’s fourth fuel drain point under the rear fuselage aft of the rear seat that is easily overlooked. It is there because the gascolator is not the lowest point in the fuel system when the aircraft is parked.

The plumbing to this drain can hold a lot of water and this moves forward to the gascolator when the tail is raised on takeoff.

This all fits with the description of this accident.

Australian regulations require sump drains before the first flight of the day and after refueling.

Dick Gower

Autonomous Anything

My answer to your question is all of the above:

  • Yes, autonomous cars would be a sensible alternative for a short hop.
  • But realistically they are a long way off before we see WALL-E like performance.
  • For now, they are a promoters/hedge fund manager’s pipe dream. It will take a trillion-dollar investment in infrastructure alteration to make this into something other than a wet dream.
  • Until that happens, they’ll have to rip the stick/wheel out of my cold dead hands.

Jack Aubrey

Sleep is Underrated

Thanks for the ‘ode to the freightdogs’ in Paul Berge’s “Sleep is Underrated” article. It’s nice to hear it from the other side. The feeling is mutual.

I’m sure I speak for the majority (of freightdogs) when I say ‘thanks’ for all the great treatment by nighttime ATC-ers around the country. We could always tell when a dayshift-regular was working graveyard. No self-respecting nighttime controller would ever put an airliner in front of a check hauling MU2 on approach! 250 to the marker was never a problem.

Reading the article brought back many great memories. Do I miss it? What the author said.

Paul J.

I do miss the night flying I used to do. I never worked a job with rotating shifts but did work 6 years on 3rd shift at my precious career so my first flying job flying on demand night freight was not a problem for me. Sometimes it hits you around 5:30 am but for the most part I did not have problems staying awake or sleeping during the day. I have to credit ATC for being helpful when flying in middle of the night dodging thunderstorms or setting me up to dive bomb a glide slope avoiding ice buildups or that short vector to join the localizer at the FAF on the ILS. Most night flying avoids a lot of the traffic issues that are common during the day (except the New York area). And no turbulence due to thermals. And when you are a medavac flight you get even more help. When I started to fly passengers during the day on my then fractional job it was a struggle to get used to what most people call normal daytime shift. I still have no trouble staying up late but about 3am is my limit now. And I still hate those 6am departures!

Matthew Wagner

Killer Gas

Please convey my heartfelt thanks to Rick Durden for penning “The Pilot’s Lounge #141: Killer Gas.” I’ve been flying with what I consider the best passive “dark spot” CO detector available. Immediately after reading Rick’s column, I ordered a small, light, easy to use active detector from Sporty’s. On behalf of myself and my family, thank you for sharing, Rick. Much obliged.

Joe Corrao

Nice article on CO detects, Rick! I have subscribed to AVIATION CONSUMER and generally followed its guidance for 15 years now. I installed in my Bonanza the CO detector you recommended well over a decade ago. It finally “died” – “After 10 years this unit will self-destruct!” But then I thought, I climb LOP and cruise LOP, with no CO produced, so I didn’t bother replacing my CO unit. So two points to be made.

There is minimal risk of CO if you fly LOP exclusively.

Surely the proactive pilot will heavily insist on his/her mechanic thoroughly inspecting the exhaust, heater box, and cabin heat source (in a twin) at least at every Annual Inspection. Heck, why not be present during that inspection? Further, Shouldn’t every pilot learn to do the inspection him/herself, in order to be confident throughout the year and be sure any unfamiliar plane (rental?) is not ingesting CO in the first place?

Attacking the root cause is usually better than addressing symptoms. And “belt & suspenders” might be the best of all worlds in this case!

Jim Herd

Bernoulli Had It All Wrong

Yes, when I was a kid, the first explanation I read for lift used exactly the “straw man” explanation: the camber of the wing means the air going over the top has to take a longer path, so it has to move faster, and then Bernoulli says the pressure drops and holds the wing up. In fact, some versions of the “explanation” went so far as to say that since the bottom of most wings is fairly flat, the pressure there didn’t change much, so “most” of the lift was from the “top of the wing”. This “explanation” was bunk. But, Bernoulli was entirely right. Starting with the Newtonian explanation, we observe that the wing does, in fact, deflect air downward. Now, for the air to be deflected downward as it passes the wing, the pressure above the wing has to be lower than atmospheric pressure, so that air going over the top is deflected downward, toward the lower pressure. And, below the wing, the pressure has to be higher than atmospheric pressure, so that air going below the wing is deflected downward, away from the higher pressure. But, this means the pressure above the wing (lower than atmospheric) is lower than the pressure below the wing (higher than atmospheric), so air approaching the space above the wing will accelerate toward it, while air approaching the space below the wing will slow down – exactly consistent with Bernoulli’s rules. And, the velocity difference is often much bigger than could be explained by the wing camber. Everyone is right, and everyone gets a medal – like Physics Theory Self Esteem Week!

Thomas Boyle

Water. Boats. Wakes. Air. Wings. Wakes. If, through forward motion through the fluid, you evacuate a fraction of the air that occupies the space ABOVE a wing (as occurs with any POSITIVE angle of attack, right out to 90 degrees), the evacuated (“wake”) area will exhibit a lower pressure than exists elsewhere locally – as in the space BELOW the wing, for example. Higher pressure below; lower pressure above; wing in between. In which direction will the wing want to migrate? “Lift.” Satisfies most pilots; works for all airfoil cross-sections. Compatible with drag, acceleration/stagnation, laminar-flow/separation, Coanda, etc. This reminds me of the sections that I taught at a local community college, where the most common question was: “why should we care?” The dominant attitude was: “I don’t need to know how an automobile engine works, in order to drive a car. Why should I NEED to know how an airplane engine works, in order to fly a plane?” Good question.

Tom Yarsley