Minimum height for practice stall recovery in C172
Question: Traditionally most flying schools mandate that the minimum height above terrain by which to recover to level flight for stall recovery practice is 3000 feet - meaning the pilot must be above that height on commencement of the practice.
There appears to be no CASA regulation nominating that restriction. What is the rationalisation for that stall limitation? From where did that "tradition" start and is it a valid requirement considering the POH for the Cessna 172 states "Altitude loss during stall recovery may be as much as 230 feet" This would suggest a recovery policy by 3000 ft is grossly exaggerated and not cost efficient to the student. Stall recoveries are not aerobatics where there is a 3000 ft min height restriction. |
I wouldn't like to face the legal argument that a stall is not an aerobatic manoeuvre. It is a manoeuvre where you don't have full control over the aircraft. There is no clear definition of aerobatic flight (ask John Quadrio who lost is licence over a technical point about aerobatics that CASA won in the AAT). However, the FAA definition is widely accepted:
Any manoeuvre involving an abrubt change in an aircraft’s attitude, an abnormal attitude, or abnormal acceleration, not necessary for normal flight Remember that the Cessna height loss figure comes from a perfect aircraft. Add in some mis-rigging developing over the years, a cofg at the back of the envelope, wrong initial control inputs from a student and the answer will be completely different. And I have a mate who is dead after giving a potential purchaser a test flight who stalled the aircraft then messed up the recovery without sufficient height for my mate to recover it. You know the saying about useless things in aviation.... |
I have always understood it to be "recovered by 3000'" - although I would have to admit to doing stalls much lower than that, with a highly experienced instructor. :E
Dr :8 |
It was explained to me during that part of my training that although stalls were not considered aerobatics, in the absence of a set rule it made sense to follow the requirements for aerobatics just to be safe (recovery by 3000' being one of them).
I'm not sure how much a student would save by doing stalls below 3000. Not much compared to the price of a new aircraft after you have a prang in this one, I'm guessing. Out of all the things you could complain about the cost of flight training this would have to be low on the list. Although... Maybe it's a big conspiracy by the flight school to get an extra $10 out of students? :rolleyes: |
Wing at 16 deg AOA, stalled, wing at 15 deg AOA, unstalled. Height loss about 10ft at most, as you move the stick fwd a fraction to effect the 1 deg pitch change. :ok:
Now going from 16 deg AOA stalled to 0 deg AOA nose at 20 deg negative pitch dive while pushing full power, then you will lose far to much height than actually needed to recover.. :ugh: What method is taught the most and why? And which method of stall recovery would you prefer if you stall on mid or short final? (Yes, final, not finals, you can only fly 1 final at a time) bury the nose into the ground recovering, or just releasing enough back pressure to get the wing from 16 to about 15 or 14 deg AOA, where it will still fly happily, unstalled. Even in a turn....:ok: assuming you know how to use a rudder and the ball is centered. |
As I understand it there is no legal requirement to begin or end your stall at 3,000ft however it has long been considered best practice in training circles.
As I understand it you would be free to stall an aircraft at 1,000ft. |
It's the school's plane and the school's instructor, if they say recover by 3000' (which by the way is usually written in the ops manual so I suggest you check it), then end of story, that's it.
Your own plane, the safety of the flight is your responsibility, and if there is no regulations regarding it, it's your call. Keep in mind that an inadvertent spin can take 1000'+ to recover! |
Those who don't think stalls are an aerobatic manoeuvre should read the thread on John Quadrio. He was hung out to dry by CASA for a more benign manoeuvre on the basis of a passengers video.
Also remember that schools teach 1g level flight stalls. As a previous poster correctly identified you can achieve 15 deg AOA at nearly any speed in nearly any attitude |
And which method of stall recovery would you prefer if you stall on mid or short final? (Yes, final, not finals, you can only fly 1 final at a time) bury the nose into the ground recovering, or just releasing enough back pressure to get the wing from 16 to about 15 or 14 deg AOA, where it will still fly happily, unstalled. Even in a turn....http://images.ibsrv.net/ibsrv/res/sr...ies/thumbs.gif assuming you know how to use a rudder and the ball is centered. Have you ever stalled a C150, PA38..............or even a BE35 with 20o flaps and 1800 rpm ? I used to instruct in a PA38 that would promptly roll onto its back every time! Dr :E |
Do not forget that the aircraft is not the only threat during stall practice. I know of at least three instructors who have had a student lock up on the controls with full back pressure during stall practice and lost 1000-2000 feet during the recovery. One of these was in a PA28 which suprised the student with a wing drop in a straight and level power off stall.
Whilst a straight and level stall may not constitute an aerobatic manuevre it can very quickly turn into one without much warning when inexperienced pilots are involved. |
Hmmmmm, I regularly stall aircraft at zot feet. It's how we land.......
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Hmmmmm, I regularly stall aircraft at zot feet. It's how we land....... |
So what's the suggestion .... I clearly recall an inverted spin in a PA38 with a 1500ft recovery, with a highly experienced (22 hour) student. I live today as a result of having 4000 ft to play with on the way down .... happy to pay the extra 3 minutes of climb time for that myself ... :ugh:
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The C172 G1000 POH states that slow deceleration stalls are not considered aerobatic (excluding whip stalls). Refer section 2 of POH.
The recovery by 3000ft is an arbitary figure that is unneccessarily linked to aerobatics practice and carried through by generations of Instructors. I've seen Ops manuals that approve straight and level stall practice below 3000ft with CFI approval. I'm not aware of any CASA height rule regarding straight and level stalls, only aeros. |
happy to pay the extra 3 minutes of climb time for that myself |
Excuse My Limited Aerobatic Experience
Avgas172
an inverted spin |
A large bunch of precious pansies in this thread.
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The C172 G1000 POH states that slow deceleration stalls are not considered aerobatic Height itself is not necessarily an issue. I used to do flick rolls below 1000 ft in competition. Its all about the context. |
What is the rationalisation for that stall limitation? From where did that "tradition" start and is it a valid requirement considering the POH for the Cessna 172 states "Altitude loss during stall recovery may be as much as 230 feet" Have lost 500 in a deliberate stall in a J160 in go round mode (full flap full power). Stall was deliberate spin was not. I do have the upright spin bit in the logbook so not so bad when you start at 3,500. No more stalls till I have had an session in a 152 Aerobat with instructor with me in the RHS (L Hand on throttle R hand on stick-wheel). Now think of student recognizing the problem and trying to remember theory or even the G3 200 hr instructor also headed down - needs time = feet. |
CAR 155
(2) For the purposes of subregulation (1), straight and steady stalls or turns in which the angle of bank does not exceed 60 degrees shall be deemed not to be acrobatic flight.
(3) A person must not engage in acrobatic flight in an aircraft: (a) at a height lower than 3,000 feet above the highest point of the terrain, or any obstacle thereon, within a radius of 600 metres of a line extending vertically below the aircraft; or (b) over a city, town, populous area, regatta, race meeting or meeting for public games or sports. Therefore there is no height requirement for stalling except for the requirements in CAR 157. |
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