Stalls

[motzartmerv]

Yea, good post turbo..

 

I only have one point of contention.. The stalling speed with angle of bank.. I really wish more RAA instructors would use the lift formula when discussing stalls (and other things)..

 

In a 60 deg bank LEVEL turn, the wing loading is doulbled, it has to to keep lift sufficent to overcome the weight (which is essentially now doubled).. As we all know, the stall speed increases by the sqaure root of the G loading.. At 2 g's the VS increases by 1.4 ishh..

 

But....

 

If you just bank the wings over to 60 deg and let the acft descend, ie, not a level turn, a descending turn, the g loading is still only 1+ . The lift force acting perpendicular to the wing is tilted and the verical component is not enough to overcome the weight so the acft descends.. That has no affect on the stalling speed..

 

BUT here's the clincha... In a descending turn ie turning final, the stalling speed (or the speed at which the stalling angle is reached) is unchanged, but if you overshoot the turn and increase the bank angle and THEN come back heavily on the stick to try and reallign, you can stall but because the wings are banked, the lower wing will stall before the outside wing, and the outside wing will keep flying..

 

The results are obvious..

 

Its prescicely this scenario that leads me to think that useing opposite rudder instead of aileron could be a lifesaving descision..

 

cheers

 

 

[turboplanner]

Thanks Merv

 

 

[Mazda]

Mozart is spot on about the descending turn. People always think in terms of level turn because that's what the books talk about. The stall speed is not doubled in a descending 60 degree angle of bank turn.

 

That's why I say sure, go ahead and get the books, but you won't know for real until you are up there doing it, so get some decent training. For example everyone knows that if you are inverted and pull back, you'll pull into the ground. All the books say so. But I can assure you that many pilots without real life EMT/aeros training who somehow end up beyond 90 degrees angle of bank will pull as an initial reaction, even if they have read the books.

 

Turboplanner I sure hope I don't have the Airtourer you were doing that in, because the manual is specific about what you can and can't do to avoid a 20 times shorter spar life, and tail slides are not approved! Stall turns are of course, but not tail slides.

 

Actually here's an interesting point. "Stall speed" is for slow deceleration level stalls and has no bearing on some real world situations. You can be pointing up in a stall turn, with the airspeed reading zero, and depending on the type you can count a bit and still keep going up (and not stalled). So you can be at zero indicated airspeed and not stalled. Or you can stall at a speed much higher than the published "stall speed."

 

But I'm getting off the track.

 

You CAN fly a stall, I've done so many times, you can do falling leaf type things, fully stalled, not spinning. You will be descending, but still flying.

 

Or you can put in some rudder and spin, still a controlled state of flight in an aircraft approved for spinning. Aerobatic pilots do that all the time - upright, inverted, flat, with aileron, with power etc. Stalling doesn't mean uncontrolled flight or falling out of the sky. A flick/snap is a stalled state of flight too, and the aircraft can be flying horizontally.

 

 

[Guest Maj Millard]

Big topic of course,which I won't wade into. Flew a Slepcev Storch a couple of days ago, and they just don't !. I'll offer a rant I came up with sometime in the past....

 

"The wing is King, airspeed you need, you stall you fall"...............The Major...........................

 

 

[farri]

When i first sarted flying in 99 i was told to never use Aileron to pick up the wing after the stall. now i was reading the Jim davis PPL book and he says its ok to use the Aileron to help recover from a stall?shafs64

I`ve never read the Jim Davis PPL book but I have read quite a bit of discussion on this thread and my question is this, "With only the information that`s been given how can we come to an accurate conclusion on weather it`s ok or not to use the aileron to help recover from the stall".

 

The make of aircraft is required, because ,they don`t all behave in the same manner due to their design, some have ailerons that are fully effective throughout the stall and others do not, and also,at what point in the stall is the AC and how much use of aileron are we talking about.

 

Talking generaly isn`t going to shed much light on on what Jim Davis may be saying, is ok.

 

Cheers,

 

Frank.

 

 

[shafs64]

Well most of my trainning has been on C172s witch can have a nasty stall. all my stalls have been power off.

 

Shafs

 

 

[turboplanner]

Thanks Frank, you are spot on.

 

Shafs, if you've only stalled power off, you ain't seen nuthin as they say in show business, and I would have to ask what the hell your Instructor thinks he's doing. I can only repeat my earlier advice to do some serious study using professional reference material, and if necessary get an instructor who knows what he is doing before you have a serious accident.

 

 

[shafs64]

Well i dont fly 172s anymore i fly tecnams p2002. i will be getting my instructor to teach me some power on stalls.

 

Paul.

 

 

[turboplanner]

OK, then that's the time to ask him/her when and how much to use aileron, and when and how much to use rudder, and then it will all come naturally, and don't forget to buy the book.

 

 

[Guest pelorus32]

Interesting - just went to the Ops Manual and had a look at the stalls requirements for High Performance which would cover the P2002. Rotten document is password protected so here's a picture of the requirements:

 

[ATTACH]7444.vB[/ATTACH]

 

Regards

 

Mike