MajorTomski

Please, enlighten us, cite a reference for that. My -182 stalled at 51 MPH no power full flaps. My -182 full power, full flaps wouldn't stall at all. STOL conversion kit, No stall is a function of angle of attack, g loading and power.

dirtybird

My Feedback: (5)

If you change the configuration of the A/c of course it will change

invertmast

My Feedback: (23)

As a CFI with 1000hrs of dual given, i spent many hundreds of hours doing exactly what he stated. I remember one day i was with a student in a C152 at 8,000' msl. With a headwind at vso +5 we had a ground speed of negative 15kts. The lesson for the day was slow speed manuevering. 90* turns no problem, 180* turns didnt result in any indicated airspeed change, but a descent rate Would be noticed IF the student did not anticipate or correct with the application of More power.

Point being, indicated airspeed doesnt change if all things are kept equal throughout the turn, ground speed will increase as the turn to downwind is completed, rate of climb/descent will change.

Jaybird

May I assume the the banks were shallow and that every control input was done gently? That's how my CFI worked slow flight with me. I think RC pilots assume that they can continue to yank and bank regardless of how close they are to the critical angle of attack.

Jaybird

p.s. Slow flight is quite a challenge and fun with both full size and models especially when your reserve power is limited.

invertmast

My Feedback: (23)

mostly, depended on the plane, but smooth inputs and 20-25* bank angles were typical. . Later on when they became more proficient, bank angles increase to up to 45*

Sport_Pilot

Newton did not do all of his calculations from the center of the earth. He had a theory of relativity. But, you are several centuries out of date. Einstein took that and added so much more to his theory and made it his own with his "special" and "general" theories of relativity.

Lownverted

My Feedback: (4)

Because you are measuring GROUND SPEED, not air speed. The radar gun, (or doppler mic, or whatever) is stationary on the ground. You are measuring the aircraft speed relative to it, not to the surrounding air mass. If you were,with say a pitot/static system on board, you'd be measuring airspeed. Since you are in fact measuring ground speed, wind makes the upwind and downwind passes different, hence the need to average.

dirtybird

My Feedback: (5)

You are not making a 9g turn. Our models make more than 9g turns at times.

dirtybird

My Feedback: (5)

He added more theory but he did nothing to alter the basic concepts.Newtons work still stands.h
I am certain he never said acceleration depends on which way the wind blows

drac1

My Feedback: (4)

So you were going backwards? Interesting.

Jaybird

I believe he wrote 90* (degree) turn (as from going from directly North to going directly East) not 9G turn.

Jaybird

Jaybird

Relative to the ground.

Jaybird

Sport_Pilot

I don't think that you understand that Newton had his own theory of relativity that did not include the speed of light or space-time. His theory would explain why a plane flying a high g circle would make a circle when viewed from a balloon and an elapse when traced on the ground.

Sport_Pilot

Your explaination explains what he said better than what you are saying. The accelerated stalls of the high g turns is one of the things that get false explained with the downwind myth.

drac1

My Feedback: (4)

I know what he meant, but I doubt very much he was going backwards relative to anything.

Jaybird

Why not? I've seen model planes hold altitude in a strong wind and move backwards relative to where I'm standing. I've read stories in the flying magazines (AOPA, Flight Journal) of passengers in a Piper Cub watching the trees and ground moving forward on an especially windy day. If the wind is blowing 50 mph and the plane you are in can do slow flight at 45 mph then the airmass you are flying in will move you backwards at 5 mph.

Jaybird

drac1

My Feedback: (4)

It makes me laugh when some compare models to full size planes.

Even if he was right on the stall, he would need a 55 knot headwind to go backwards at 15 knots. That's a 63 MPH headwind at the very minimum without falling out of the sky.

Take everything you read with a grain of salt.

Jaybird

Good advice!

Jaybird

Sport_Pilot

Why 55 MPH my old Kadet would fly easily at 30, maybe less. Not near a stall either.

Snides

The most basic understanding of aerodynamics and performance dictates that airspeed does Not change with regard to the airmass in which it is flying unless pitch or power has been altered.

Jaybird

That was a full scale example not a model.

Jaybird

PacificNWSkyPilot

My Feedback: (19)

Hey, Jaybird!

How are things back home? I'm from Newport/Plymouth area. In fact, the cub I mentioned crashing due to a downwind turn crashed on Plymouth Pond in the middle of winter, I think the year was 1991.

Jim

cfircav8r

My Feedback: (1)

so the way I understand the argument is if you are traveling up wind going 60mph and the wind is 20mph you are traveling 40mph ground speed and you turn down wind and now have to have sufficient airspeed to allow the plane to accelerate up to the 80mph ground speed before you stall, due to the momentum. lets look at it logically. what causes the GS to be different than the AS? You are flying north at 60mph and the wind is moving south at 20mph. 60-20=40, therefore you are flying 40mph GS. now lets say you are flying south at 60 and the wind is moving south at 20. 60+20=80, therefore 80mph GS. so you can look at it this way, and any physics professor will agree, in relation to the ground you are traveling 20mph south all the time. this can be seen by the need to crab on cross wind. you are traveling 60mph AS the whole time as well. so we can agree that the airplane upwind has 60mph worth of momentum through the air northbound and 20mph worth of momentum southbound equaling 40mph of momentum. heading south the plane has 60mph of momentum to the south and the wind has 20mph of momentum to the south equaling 80mph of momentum to the south. do you see the constant here? the wind is always providing that 20mph worth of energy to the south and the plane is providing the 60mph worth of energy so if you add energy by throttling up you will have excess energy. there is no change in momentum due to the wind when changing direction. the only part that could account for that would be the turn and that, if flown the same, is identical with or without wind. anyone still doubting it run this by a physics professor and see what they say.

dirtybird

My Feedback: (5)

The error of that hypothesis as I see it is you are relating momentum to the wind. Momentum is related to the earth not the wind.
I don't know any Physics profs but I know some fellow aerodynamic engineers at Boeing. I will run it by them

cfircav8r

My Feedback: (1)

no i'm relating it to the ground, hence the ground speed. i am just pointing out where the energy is coming from, IE: the plane and the wind separately.