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View Full Version : Forcing benign aircraft to stall to make a point.


Tee Emm
13th Jul 2010, 13:54
The Australian Civil Aviation Safety Authority (CASA) Day VFR Syllabus flight test form requires a candidate for the General Flying Progress Test to be tested for competency at stall recoveries and also recovery from a stall with wing drop.

Many light training aircraft have benign stall characteristics and this includes no indication of a wing drop. Indeed to induce a wing drop at point of stall it takes gross control movements to the point where it would be doubtful if a student would ever be placed in such a situation. Some instructors therefore will artificially induce a wing drop by raising the nose sharply and applying firm rudder in the direction of the desired wing drop then hand over control for the student under test to recover.

My point is this: If the aircraft type on which the test is conducted does not stall in the classic manner (such as sudden nose drop?) because of modern design, is this sufficient to adequately assess the students ability to recover with minimum loss of height. Along the same argument, if the wing simply does not drop, then forcing a substantial wing drop artificially by aggressive rudder and asking the candidate to recover - is this a valid "solution" so a box is ticked that he is certified competent to recover from a wing drop at point of stall?

If at a later date the student is to convert to another aircraft type, should he be also tested by an instructor for stall recovery competency on that new type? This is because the stall characteristics may be different from the type he was originally tested on for his GFPT.

Some PPL syllabus require a student to demonstrate skill at stall recovery from a gliding descending turn. To get into that situation where a stall occurs requires significant or even gross mishandling which could overstress the airframe. Is it wise therefore to expect the candidate under test to try to obtain these gross atttitudes to force a stall?

In the "old" days some trainers such as the Chipmunk, Wirraway and even the Tiger Moth easily displayed the classic stall symptoms where the nose and one wing could drop sharply. Maybe the rigging was incorrect but it happened and it didn't take much to cause the aircraft to enter an incipient spin if stall recovery was botched. But some flying school syllabus of training today still assume all aircraft display the "old" stall characteristics. And if their aircraft are benign, instructors fix that minor problem by deliberately forcing these aircraft into impossibly unrealistic attitudes to tick the required boxes.

Your thoughts would be greatly appreciated because I for one, feel account should be taken of the much safer stalling characteristics of current flying school trainers and that forcing stalls is too artificial and simply wrong technique.

Pilot DAR
13th Jul 2010, 19:14
I suppose it's a matter of what you're really trying to accomplish. Over a range of types, and conditions, you will find everything from will hardly indicate a stall at all while decsending, to drops a wing, and goes 'round a turn no matter what you do.

I cannot speak for the training standards being applied, but the standards for stall handling of any plane certified since about 1948 will be fairly equal, and well described (have a read of FAR part 23). The standards for dropping a wing are pretty clear, and I have certainly flown some types which did not meet the requirement - one was brand new!

It's a good thing for all pilots to have a feel of getting in and out of a stall, and a spin, but they are distinct maneuvers, and should be treated as such. If a spin recovery is necessary for a well entered stall, I'd snag the plane for a rigging check.

If the instructor is aggravating a stall, because that is the standard to which he should train, so be it - but it sounds odd to me.

BOAC
18th Jul 2010, 07:28
Back in the days when I used to 'do it' on C150's etc, a trickle of power as you approach the stall was normally enough to produce quite realistic wing drop without any rudder input and was not too 'obvious' as a fix.