shdw

This is a question I ask almost everyone I fly with. "So if I want to do a 60 degree bank, level turn, at Vne, will I over stress the aircraft?" As plasticpi said, no you will not. Speed is irrelevant for g forces, in a level turn, it is nothing more than simple trig [1/cos (bank angle)]. Do it in your calculator and you can find out the g's for any turn.

Me personally, in demonstrations, I have sustained a 75 degree bank turn or their about, at 110 knots in a 172SP. The demonstration was to give an introduction, that I could gauge for structural safety without a g-meter, into how g-forces can effect ones body in unusual attitude recovery. Yes, we were in utility category.

snippercr

I guess I should check the regs but I dont have one in front of me... I thought 60 degrees was the max bank angle you could fly in a normal category aircraft.

fatmike69

60 degree bank in level flight at Vne? Better be pretty smooth on the controls, have smooth air, and hope you don't have to maneuver suddenly for traffic or whatever reason. Any correction for altitude loss in the turn will load the wings further, and at that speed the airplane will allow you to exceed the g-limit, probably pretty considerably.

plasticpi

If I may, I'd like to defend shdw, saying this:

Nobody is advocating doing extreme banked turns, whether below, at, or above Va. The point is just that bank angle alone does not equal excessive Gs. You can roll the aircraft through 90 degrees, inverted, and level again without exceeding the load factor limit for any aircraft. Can you do it without exceeding speed limits? I don't know. Can you do it, keeping the speed within limits, without exceeding load factor limits? I don't know. The point is purely academic. Airspeed has nothing to do with the load factor in a level, banked turn, all other factors aside.

watchyouralt

Well hypothetically sure but that would be in a perfectly level turn condition. Any small acceleration, which is more than likely when flying, could cause a significant load. So yea you're right, in level flight speed doesn't matter, but the higher the airspeed the higher the load once that airplane is accelerated.

Twin Wasp

All y'all must be young, the old FAA standard for steep turns on checkrides WAS 60 degrees.

And why would having a CFI onboard make a difference about wearing a parachute? Is there a 70 degree bank maneuver required for a rating?

rickair7777

That's kind of vague and not literally spelled out in the regs. You cannot conduct "acrobatic maneuvers" in a normal category. Acrobatic flight is defined to include "abnormal attitudes" so I think the FAA would probably consider 70 degrees as acrobatic but hard to say for sure.

Also if you intentionally exceed 60 degrees, you need parachutes. The 91.307 exemption does not apply since 70 degree steep turns are not required for a rating.

shdw

The 60 degrees at Vne was completely hypothetical. It's only purpose is to find out if the student understands g-load. Many people, including instructors, believe you need to be at Va to safely fly steep banks. This is a complete myth.

In my Cap10 flying days, Va was 127. Want to know what we flew an immelman at? 130. Outside loop (inverted loop)? 145. Aerobatics are routinely done well above maneuvering speed. Watch patty do a 200 knot pass and pull vertical, Va in her aircraft is 130s or there about.

Also, Va has absolutely nothing to do with rolling the aircraft. You can be at 90 degrees with no load on the aircraft (knife edge). G-load is directly related to the elevator and the actions made with that control.

Let's take this one step further:

Scenario 1: If you are in a 60 degree bank turn, at Va, and you smoothly, but quickly, pull (not snap, discussed next) the controls all the way back to cause a stall, do you over stress the aircraft? Surprise, yes you do. But wait, I was at Va? Yes, you were, but not within the design of Va.

Scenario 2: If you are at Va, in level flight, grab the controls with both hands and yank the elevator to your lap, are you within load limits when you stall? Again, no you are not. Consider a scale, with a max weight of 150 pounds and you have 150 pound weight. If you set the weight on the scale, all is well. What if you drop the weight on the scale? Yup, it breaks.

Many people will likely question this one. So here, right from the Cap10B manual. Snap maneuvers: The maximum authorized speed for snap maneuvers are: Positive = 95 kts and Negative = 105 kts. Pretty far below Va of 127, don't you think?

Have you ever noticed, in some aircraft, they have a speed for heavy turbulence penetration. Ask yourself this, next time you see one of these speeds, why is this speed below the designed Va? Maybe someone here has an example they can post.



Va is designed with 2 factors in mind when tested:

1) The maneuver is symmetrical, meaning not in a turn.
2) The maneuver is progressive, IE, NOT sudden, full deflection, of the controls.



I hope that wasn't too much rambling for anyone.

USMCFLYR

shdw -

Did you mistype the Vne in the sentence above from your post?

USMCFLYR

shdw

Yes, corrected. Thanks.