Power On Stalls, what's the point?

[MLS-12D]

A couple of links that may be helpful:

Power-On Stalls defined and explained, and recovery practice discussed

I'm scared of departure stalls (Rod Machado Q & A)

[BEagle]

So they even expect these things to be demonstrated in turning flight, with full power until the point of stall...

This reminds me of 'Spinning 2' which we used to do in the RAF - reognise and recover from an incipient spin at any stage of flight. It was simple, really - if it buffets, relax the back pressure and keep the ball in the middle.

I tried one of these full power stalls in a Cherokee 140C yesterday in straight flight; the attitude needed to induce a stall in the clean configuration was quite steep and extremely unlikely ever to be selected inadvertantly. To me it seems a rather pointless and inherently dangerous manoeuvre; if correctly trimmed to an initial climb attitude corresponding to 85mph, the control forces needed to increase pitch until the a/c stalled are not something that any properly trained pilot would ever be likely to use in practice.

[High Wing Drifter]

Smile posted 11th January 2005 00:20 Click Here to See the Profile for MLS-12D Click here to Send MLS-12D a Private Message Edit/Delete Message

A couple of links that may be helpful:

Power-On Stalls defined and explained, and recovery practice discussed

I'm scared of departure stalls (Rod Machado Q & A)

I guess the FAA deems the PoS relevant to PPL training because of the existence of 6000' airports in that coutry.

[Final 3 Greens]

I guess the FAA deems the PoS relevant to PPL training because of the existence of 6000' airports in that coutry.

That's a fair point, HWD. I have flown out of a 6,700' airfield and you have to monitor the airspeed (as a surrogate for AoA)carefully, especially as the groundspeed looks a lot higher than normal, for a given airspeed. (Because it is!)

However, the pitch of the aeroplane looks quite shallow in the climbout and as Slim Slag said it is easy to get near the stall without realising, if only relying on the "normal" visual cues from departing out of airports at lower altitude.

BEagle, I believe that your comments are fair and show why this manouevre is relatively meaningless if executed at lowish altitude.

The attitude is less steep if you do the stall at 7,000', but the lack of ground references make it less experiential than departing from a mountain airport, which is what grabbed my attention ... along with a well extended take off run.

That could make a pilot who hadn't planned tend to rotate and climb over aggressively (i.e. fear of obstacles on track) and I could see how that could cause a fatal stall/spin accident.

[Sensible]

BEagle, try flying at 7,000ft msl at 65kts, alpply full power, trim the aircraft in a climb to simulate a take off at a high altitude airport, trim the aircraft for the climb and then pull back the yoke slightly or overtrim to simulate clearance over rapidly aproaching pine trees at the end of the runway so that your airspeed gradualy decays and the aircraft stalls. That is I believe the intended practice scenario.

[slim_slag]

..... and then when you have got off the ground at the high altitude airport and think you are going to hit the approaching pine trees and turn to avoid, you are at increased risk of a turning power on stall.....

[englishal]

Well I think that anyone who doesn't want to become confident at recovering from all manner of stalls is kidding themselves. An aeroplane can stall at any airspeed, any configuration, any attitude and any altitude......

A PPL student should be confident at recovering from the basic stalls (full power and no power) as a minimum before being allowed solo.

[Croqueteer]

Englishal, spot on!

[Sensible]

My opinion exactly!

[2Donkeys]

Go on then -- me too!

[Genghis the Engineer]

And a qualified pilot should maintain at-least that level of ability.

G

[Chuck Ellsworth]

Can anyone here guess what my opinion is on this subject?

Chuck E.

[2Donkeys]

It would be good to hear it

[Final 3 Greens]

So how do you all feel about the preference of some US instructors to recover at the stall warner, by adding power and maintaining level flight?

I scared the "@@@@" out of one US CFI on my first BFR (different story) by using letting the stall develop to the break and then using the UK recovery of pitching slightly down as I added power ... the height loss was only about 100'. CRM broke down, since we agreed to do stalls, but never discussed the recovery technique, both of us assuming that we knew what the other was expecting - I was his first UK stude and vice versa - that was a useful learning point in itself.

He did explain that he was concerned that recovering in this fashion was dangerous, since the critical stalls would be enountered at low level and there was a risk of hitting the gound unless level flight was maintained. He quoted an FAA advisory, but it was back in 1996 and I can't remember the reference to be honest. He also explained that is why they are so keen on stall recognition and prevention in the US ... i.e recovering at the warner, not the actual break.

BTW, I do agree with Englishal's view.

[2Donkeys]

So how do you all feel about the preference of some US instructors to recover at the stall warner, by adding power and maintaining level flight?

I am not sure that you can pin a nationality on that recovery. What you have described is, more-or-less, the standard recovery taught for jets. The technique is standard FlightSafety fare for types like the Citation.

It works remarkably well in the more powerful GA types too, but is arguably less applicable when talking about C152s and the like. It certainly works very nicely in underpowered bone-shakers like the Seminole.

Would it be a safe bet that you regard this as thinly disguised assisted suicide?

2D

[Final 3 Greens]

2 Donks

You are being very silly now.

I asked an open question, because I am genuinely interested in what the forum thinks - maybe not so much in your case, as you are filtering your replies through a pre-expectation.

I repeat that the instructor quoted FAA guidance, so in this context I can pin a nationality on the advice in this context.

There seems to be genuine merit in the instructors argument to me, but like an earlier poster said, it would be good to understand the FAA and CAA views and evaluate the differences in logic.

Also, it would be good to hear from people like Chuck or BEagle who are both very experienced pilots and instructors.

The comment about the Citation is not very interesting to me, since I won't ever fly one of those, but the Seminole is, as I have a little experience of underpowered twins.

The only "jet" experience I have is in a sim and I seem to recall that the recovery on that type (swept wing) was a fairly aggressive push forward at the stick shaker. Mind you, that was an early generation type, with super stall vices and no doubt the technique is type specific.

[MLS-12D]

Would it be a safe bet that you regard this as thinly disguised assisted suicide?

Please register my vote in the "yes" camp.

I know nothing at all about flying jets, but in my mind this recovery technique is unfortunately typical of the FAA's on-again, off-again confusion about which controls airspeed: pitch or power.

IMHO, "recover at the stall warner, by adding power and maintaining level flight" is simply muddleheaded (this comment is not intended as a criticism of F3G, who is just reporting the nonsense spouted by an "instructor"). Try it in a sailplane and see how well it works! See further here, and chapter 9 in Stick and Rudder.

Of course, I know that things are not quite as simple as my post implies. But essentially, any stall recovery technique that emphasizes power to the exclusion of pitch is, in my mind, fundamentally flawed.

[2Donkeys]

It is a shame that you have dismissed my posting as Silly.

The information within it is accurate. The reason that many instructors are keen on the technique (as are many flight schools - Lufthansa to name but one), is that they see it as offering a ready transition from the handling of small aircraft, to the handling of airliners.

It amounts to the same rationale as certain schools have for developing extensive MCC Challenge-response checklists for PA28s. It is not that they are necessary, but they offer a better transition into the cockpit of a commercial jet, once the basic training is set aside. To somebody like you with no ambitions beyond small GA types, the technique may seem irrelevant.

2D

[Final 3 Greens]

Would it be a safe bet that you regard this as thinly disguised assisted suicide?

The above quote is the silly part and it is not accurate, since it is ill informed speculation.

Do the words "genuine merit in the instructors argument" suggest a closed mind to his opinion?

And having experienced about 15 hours of LOFT in a sim, I am aware, at least to some degree, of the differences between light aircraft and airliner operating differences.

However, the context of my question was a generic PPL BFR, not Lufthansa's line oriented school, who may validly use MCC techniques in SEP as a lead in to the use of checklists for potential flight deck, or choose to teach stall recovery techniques that lead in to high performance aircraft.

The instructor specifically discussed the recovery technique in he context of GA SEPs, not as line oriented training.

To somebody like you with no ambitions beyond small GA types, the technique may seem irrelevant.

What point are you making here? MLS12D has already given a view based on referenced material, applicable to a PPL - I would be interesed if you could do the same, although if you prefer to make remarks as baseless as the quote heading this response, I could do without your input.

[2Donkeys]

You asked for input on a technique of stall recovery, you got it.

Since you have sought to pick fights throughout I'll leave it there.

2D