Revised stall procedures

[Planechaser]

It's the old addage in a light plane; if you are about to put yourself in a situation, have your hand on the throttle, and if you have to take your eyes away from front and center, be moving it smartly to the firewall!

 

 

[djpacro]

This new Safety Notice from the UK CAA (40 kb pdf) is definitely relevant to G.A.

 

Recent observations by CAA Training Inspectors have raised concerns that some instructors ... have been teaching inappropriate stall recovery techniques...The standard stall recovery technique should therefore always emphasize the requirement to reduce the angle of attack ....

[kaz3g]

This new Safety Notice from the UK CAA (40 kb pdf) is definitely relevant to G.A.

Hi DJP

 

Point taken...

 

I guess what Pat was telling me was he didn't like me relying on the slower return to flying speed and loss of height that accompanies the lowering of the nose below the horizon alone when the combination of a much smaller reduction in AoA and full power is an available option.

 

On the other hand, my RA instructor was pretty keen on me getting the nose down below the horizon - and very promptly, too - no doubt because of the low inertia. Once the power was off the speed came off very quickly as well. This was in a Texan and my instructor also demonstrated a power-on stall in a climbing turn... spectacular doesn't describe it!

 

Cheers

 

kaz

 

 

[eightyknots]

"Round eyes", such as French, for instance?The squeeze between stall and Vne depends on wind loading and the Vne for a particular plane. For instance, gliders up to 100,000' have no problem. On the other hand the US U-2 aircraft has about 10 knots between the two at 75,000'.

Try as I might, I have not yet found the glider that ascended up to 100,000 feet with "no problem".

 

 

[djpacro]

.... I guess what Pat was telling me ..

I am sure that Pat was right (been nearly 40 years since I flew with him).With a nose high recovery the natural thing to do results in a reduction in the angle of attack. Aeroplanes behave pretty much normally if not stalled, regardless of airspeed and how high the nose is.

Instinct may result in a different outcome from a stall in a descending turn.

 

 

[Bill Hamilton]

This stuff relates totally to airliners operating at high altitudes. The margin above stall is only about 9 knots., depending on how close you are to "coffin corner". With airplanes that have underwing engines, ( the majority) applying extra thrust will cause a pitch up which may not be able to be controlled by the elevators, so the plane, if it isn't already, will become well and truly stalled. In this instance. It's not a question of proficiency at anything like normal stall recovery, but analysis and recognition of a situation that has only recently been assessed and understood. In search for efficiency, the limits are visited more and more. The air is very thin up there. At 18,000 feet half of the molecules of the atmosphere are below you. at about 40, 000 feet it would be around 80%.. You're talking of true airspeeds of 480 knots and a stall speed about 6% or less, below your cruise speed. You are in an environment where the plane could not do a 5 degree banked turn without getting a stall burble. You get a bit fast and you get high speed buffet. (Separation because of the airflow over part of the wing becoming supersonic). Nev

[Bill Hamilton]

------ which may not be able to be controlled by the elevators, so the plane, if it isn't already, will become well and truly stalled.

Facthunter,

Don't know where you got this "fact" from, it just ain't so, any certified aircraft must be controllable throughout it flight envelope, and then some, to the criteria laid down in the certification standards, in this case FAR/JAR 25.

 

There are a lot of other comments on this thread that don't have much to do with actual behavior of aircraft in high altitude, high subsonic speed flight.

 

In fact, the "recover" techniques employed by the AF 447 crew were those for low speed, low altitude recovery.

 

Indeed, CASA "policy" ( but not the law) in an IFR renewal requires you to demonstrate a recover with power with zero loss of height, any height loss is a fail, at at least one district office. The poor bastards on AF 447 had some other "unhelpful" issues to contend with, peculiar to Airbus. Reading the latest accident update, and thinking about "policy" for recovery from a stall leads to some really scary thoughts about what would happen here, in identical or similar circumstances of low speed, "normal" indicated attitude (v. angle of attack in a high rate of descent) and a badly out of trim (nose up) aircraft.

 

Cheers,

 

 

[kaz3g]

1. I am sure that Pat was right (been nearly 40 years since I flew with him).2. Instinct may result in a different outcome from a stall in a descending turn.

1. Close to that for me, too... are you that old?

 

2. Fortunately, instinct for me remains a prompt lowering of the nose... the gliding stuff is heavily imprinted (even though I have trouble remembering what happened yesterday) and a bit of speed close to the ground while still in control is good insurance. I can hear Mike V's voice from the right seat of the Kookaburra saying quite calmly, "stick forward, ailerons neutral, opposite rudder until the spin stops, and recover from the dive."

 

kaz

 

 

[kaz3g]

Mike V!!.....good memories!!

Yup...

 

 

[farri]

On the other hand, my RA instructor was pretty keen on me getting the nose down below the horizon - and very promptly, too - no doubt because of the low inertia.

:thumb_up: = !!!!!!

 

Frank.

 

 

[Exadios]

Facthunter,Don't know where you got this "fact" from, it just ain't so, any certified aircraft must be controllable throughout it flight envelope, and then some, to the criteria laid down in the certification standards, in this case FAR/JAR 25.

There are a lot of other comments on this thread that don't have much to do with actual behavior of aircraft in high altitude, high subsonic speed flight.

 

In fact, the "recover" techniques employed by the AF 447 crew were those for low speed, low altitude recovery.

 

Indeed, CASA "policy" ( but not the law) in an IFR renewal requires you to demonstrate a recover with power with zero loss of height, any height loss is a fail, at at least one district office. The poor bastards on AF 447 had some other "unhelpful" issues to contend with, peculiar to Airbus. Reading the latest accident update, and thinking about "policy" for recovery from a stall leads to some really scary thoughts about what would happen here, in identical or similar circumstances of low speed, "normal" indicated attitude (v. angle of attack in a high rate of descent) and a badly out of trim (nose up) aircraft.

 

Cheers,

After they fell in a stall from 370 they were at low speed, low altitude. The real problem seems to be that they did not realize that they were in a stall. If so this would have to be a serious training problem.