You will DIE if you fly a steep turn in the circuit

Flight Training and topics related to getting your licence or ratings.
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Colonel
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Ask your flight instructor to explain how the load factor goes infinite
at 90 degrees of bank. For a few nanoseconds, this creates a "Bermuda
Black Hole" causing the 172 to wink out of existence at the event horizon
with a giant sucking sound and a blinding flash due to the incontinuities
in the space-time fabric.

Happened three times last week.

Got that? It's all in the Flight Instructor Guide, under "slow flight" which
as far as I can tell, no one has ever read.


As God as my witness, I thought turkeys could fly.
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Colonel
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a 3,000+ hour pilot that lost his life in a low altitude steep turn. He was a wonderful person and a highly skilled pilot.
Evidence might suggest otherwise.
As God as my witness, I thought turkeys could fly.
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Colonel
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I'd like to point out that incompetent instructors, who tell their students not
to exceed some magical and arbitrary X angle of bank in the circuit (that the
instructor makes up) are killing their students.

What happens is that the student is trying to turn final. But he's got a tailwind
on base, so X degrees of bank isn't doing it - he's overshooting.

So the student pushes on the inside rudder to increase the rate of turn. This
increases the AOA on the inside wing.

Good Job!

Question for incompetent instructors:

What the the stall speed of any aircraft at 80 degrees of bank, if I unload the
wing and the accelerometer shows zero G?

Message to incompetent instructors: Bank is not evil, or even particularly
interesting. AOA is interesting and often asymmetrical.

It staggers the mind, how little many instructors know about flying. For example,
I take off, accelerate level and pull vertical at the end of the runway. Most instructors
would think I'm a BAD PILOT™ for doing that, and I'm ok with that judgement.

But what is my AOA, as I drive away in that vertical upline?
As God as my witness, I thought turkeys could fly.
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Colonel
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For the really dense instructors out there - most of them, I guess - I'd
like to point out that bank angle can only be used as a proxy for AOA
IF AND ONLY IF:

1) the ball is in the center
2) the aircraft is maintaining altitude

After 25 years of flight instruction, I can assure you that rarely are either
of the above necessary assumptions true when a student is flying.

Ask him to do a steep turn in the practice area. The ball won't be
centered and the altitude will be all over the place.

Clearly the dogma that bank angle is a proxy for AOA is completely false.
As God as my witness, I thought turkeys could fly.
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Colonel
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Pop Quiz:

What is a FAR better proxy for AOA, than bank angle?

You would be amazed at how few pilots know the answer to this,
despite the fact that they've spent a lifetime not stalling airplanes.

Boggles the mind.

Hint: It's not airspeed. It's not bank or pitch attitude. Far simpler.
No, it's not G, either.

(Speak up, Photofly!)
As God as my witness, I thought turkeys could fly.
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Colonel
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I haven't yet found or been shown a use for (a slipping turn)
You can see why morons that fly airplanes, struggle with forced approaches.

This guy - feel free to shit all over him - knew how to slip. In a Boeing.

https://en.wikipedia.org/wiki/Gimli_Gli ... g_at_Gimli
As the plane drew near the runway, it became apparent that the aircraft was coming in too high and fast, raising the danger of the 767 running off the runway before it could be stopped.

Pearson decided to execute a forward slip to increase drag and lose altitude. This manoeuvre, performed by "crossing the controls" (applying rudder in one direction and ailerons in the other direction)
Every solo approach I make in a biplane in the pattern, starts with the throttle
idle on downwind abeam the numbers. I carry a little excess energy, which I
dissipate during a continuous slipping 180 degree turn onto final. Remember,
I have no flaps, and the power is already all the way off.

That's a required maneuver for the CPL flight test, morons. That's how you
fly a successful forced approach - with a little excess energy.

The morons need to remember that they will never fly through a flock of
birds (Sully) and they will never, ever encounter volcanic ash, so they don't
need to worry about ever flying a forced approach.
As God as my witness, I thought turkeys could fly.
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Tailwind W10
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Colonel wrote:
Thu Oct 22, 2020 9:56 pm
Pop Quiz:

What is a FAR better proxy for AOA, than bank angle?

You would be amazed at how few pilots know the answer to this,
despite the fact that they've spent a lifetime not stalling airplanes.

Boggles the mind.

Hint: It's not airspeed. It's not bank or pitch attitude. Far simpler.
No, it's not G, either.

(Speak up, Photofly!)
How about the position of the horizon over the cowl?
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Colonel
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position of the horizon over the cowl?
AOA is completely decoupled from bank and pitch attitude.

It's really simple!
As God as my witness, I thought turkeys could fly.
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Colonel
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Pilots like to think that aircraft handling is only relevant to little
aircraft, but that's simply not the case. Let's look at Colgan 3407.

The aircraft stalled, and the four-bar pulled back on the column
so hard - and kept it there - that they did +2G snap rolls into the
ground and everyone died.

Now, AF 447. Pitot tube iced over, so that airline pilot held the
sidestick all the way back for 3.5 minutes until they all died.

Airspeed is clearly a proxy for AOA, but it's only valid at +1G (eg
straight and level flight). As soon as you are in a turn (and any G
comes on) airspeed (ie the colored bands on your ASI) is no longer
a good proxy for AOA.

The best proxy for AOA is stick position.

If the stick is all the way back, you're at high alpha.

If the pilot LETS GO OF THE STICK the nose will drop and it will
naturally seek it's trimmed airspeed at low alpha. Also allows the
ailerons to trail and get rid of disastrous adverse yaw.

Both Colgan 3407 and AF 447 would have done far better if the
pilots had let go of the stick, instead of pulling it back as hard as
humanly possible.
As God as my witness, I thought turkeys could fly.
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Colonel
Posts: 2424
Joined: Wed Jan 15, 2020 10:02 pm
Location: Over The Runway

I might mention that the best conventional proxy for AOA (airspeed)
in straight and level flight is actually a really shitty one.

Proof by example. Your aircraft is sitting on the ramp, and you turn
on the master. The airspeed is indicating zero, but the stall warning
horn doesn't come on. Why is that? According to the best proxy that
pilots use for AOA (airspeed) you are stalled. But yet, you aren't.

Note the disaster that occurred to AF 447 when they lost their best
proxy for AOA (ie pitot tube iced over). They instantly went to CLmax
and stayed there until impact.

https://en.wikipedia.org/wiki/Air_Franc ... indication
In a July 2011 article in Aviation Week, Chesley "Sully" Sullenberger was quoted as saying the crash was a "seminal accident" and suggested that pilots would be able to better handle upsets of this type if they had an indication of the wing's angle of attack (AoA)
I remember the Chief Test Pilot of the NRC asking me how I got into flying
tactical jets, which admittedly was a bit of a weird thing for a civilian to do.

I replied, "all airplanes have wings that push air down, and engines that push air back".

If you want to competently operate an aircraft, you need to learn about some
of the details of the production of lift and thrust.

Pilots have very little interest in Cl and Cd curves. I have very little interest
in anything but them.

Image

Compare that sweet, gentle flat-bottom wing curve to a symmetrical wing.

Or a thin, nasty NLF wing with max camber 'way back (eg P-51, Glasair III).
As God as my witness, I thought turkeys could fly.
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