CFI task: Flight at minimum controllable airspeed (slow flight)

Only problem occurs when the trainee is so busy talking about it that he never gets around to doing it.
 
Areeda said:
And it is a survival technique to treat the talking part as the least important task when you're too busy to do everything.

Joe
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I wish I had a recorder running, it would have sounded something like:

Me: So now we're abeam the numbers on downwind, and we reduce power...
<sound of engine going to idle>
Me: When you have a loss of engine power, the first thing is to establish best glide speed. What is it for this aircraft?
Student: 73 knots
Me: I think it's less - 65, but in this model of airplane, there's a trick - trim the airplane to maintain the same slightly low attitude you get in cruise, and you'll be very close to best glide. While we're doing this we're also turning towards the runway, and we'll adjust our path to...

<silence while I fly the airplane on a fairly smooth curving path to touchdown, with occasional grunts when my trainer/student makes comments>

<sound of touchdown>

Me:..and on rollout we track centerline and use the brakes gently...


I've built systems that do just this sort of task-shedding in high workload situations, but it's still interesting to see it happen to me..
 
TMetzinger said:
What's interesting here is that there really can't be a "specified" speed in a number for this manuever. Your speed in the turns WILL be higher than in the level flight segments - it's probably within that 10 knot margin, though. And the "book" stall speed is only a sanity check, not a target, as individual airplanes can vary based on rigging and loading. I think that the specified speed is just above aerodynamic stall - and the envelope translates to "if you stall, you bust. If the stall warning stops - you bust".

Anyway, the lesson yesterday went pretty well. The first demonstration was rough on the right turns as I still don't have the feel for the rudder pressure quite right yet. The second one was better. Landings are improving too as I get used to the right seat sight picture. The interesting thing is how my mouth shuts down when I get task saturated. I was talking through the downwind leg of the pattern on our landing when my "student" pulled the power to idle. I did a pretty nice job establishing best glide and making the field but only spoke to respond to something he said, rather than trying to "teach" my way through it. Maslov's heirarchy taking over - survive first, socialize later.
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Exactly, you really can't just jump in any airplane and properly do the slow flight maneuver. You have to take it down to the aerodyamic stall speed and find out what that indicated value is before you can really do the Slow flight manuever properly.

As for turns I don't typically go over 15 degrees of bank, Acutally I usually recommend just a standard rate turn which is often less than 15 degrees of bank. I don't know off the top of my head how much this increased the stall speed other than not much.

Brian
 
Ron Levy said:
While load factor and stall speed increase in a level turn, the bank angles you use during the MCA task are so small (typically around 5 degrees) that the effect is smaller than the amount airspeed will vary due to atmospheric perturbations in anything other than absolutely still air.
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What Ron said. If my calculations are correct, for the training airplanes that we fly (stall around 50 KCAS), the increase in stall speed for a level 10-degree banked turn is only about 1/3 of a knot. And at those speeds, 10 degrees will give you about a standard rate turn, too.
 
Areeda said:
I agree.

One point though. It is much better to verbalize "I see this so now I'm doing that because I want this other thing to happen".

And it is a survival technique to treat the talking part as the least important task when you're too busy to do everything.

Joe
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Oh absolutely -- and depending on the airplane and the examiner, it helps you keep a step ahead.

The FAA Examiner on my checkride claimed to have never been in a Bonanza and was clearly uncomfortable with stalls. I explained everything and described what would happen before it happened - after about a minute of slow flight, a turn to the right, and the weakest incipient stall we were flying back to the airport.

We spent lots more time doing pattern work in a C172 with a CB just south of the field and wind gusting form everywhere but runway heading. he seemed much more comfortable in the Cessna.
 
Fearless Tower said:
Sad thing is that I have flown with wa few instructors who seemed scared to death of flying at actual MCA......
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What was your altitude above ground with these "few instructors"? At 500 feet I'd be concerned too, especially in the afternoon.
-- Pete
 
zaitcev said:
What was your altitude above ground with these "few instructors"? At 500 feet I'd be concerned too, especially in the afternoon.
-- Pete
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Oh say 4-5000 AGL....at least one instructor was with a 'pilot farm' so to speak with its own 'on staff' DPE and they simply preferred to show slow flight with an overly healthy safety margin. I was less than impressed.

Unfortunately, I suspect that sort of thing is all too frequent at places where the students barely have a mastery of the english language let alone the airplane.
 
brcase said:
Exactly, you really can't just jump in any airplane and properly do the slow flight maneuver. You have into take it down to the aerodyamic stall speed and find out what that indicated value is before you can really do the Slow flight manuever properly.
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If you know what the aerodynamic signs of impending stall are, you can get pretty close without actually stalling. Personally, I don't even look at airspeed during this maneuver -- it's all feel and sound for me. I want my eyes outside to pick up on any uncommanded yaw movement, not inside looking at the ASI.

As for turns I don't typically go over 15 degrees of bank, Acutally I usually recommend just a standard rate turn which is often less than 15 degrees of bank. I don't know off the top of my head how much this increased the stall speed other than not much.
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If you do a 15-degree bank at MCA in a typical light single, you're going to be seeing something like three times standard rate. At a typical 50 knots or so IAS at low altitude with enough power to maintain altitude, five degrees of bank will be quite enough for a good rate of turn, and anything more will just make the examiner concerned.
 
Fearless Tower said:
Oh say 4-5000 AGL....at least one instructor was with a 'pilot farm' so to speak with its own 'on staff' DPE and they simply preferred to show slow flight with an overly healthy safety margin. I was less than impressed.
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I asked because being a pre-solo student and an inept one at that, I can never recover from a power-on stall in less than 450 feet. Usually it's 500. Our practice area's ground is about 6200 ft MSL, usual altitude is 7500 to 8000 feet. I was unable to find any guidance in AIM. FAR only has generic minimums in 61.119. FAA-8083-3A says to practice maneuvers above 1500 ft AGL.
-- Pete
 
Ron Levy said:
If you know what the aerodynamic signs of impending stall are, you can get pretty close without actually stalling. Personally, I don't even look at airspeed during this maneuver -- it's all feel and sound for me. I want my eyes outside to pick up on any uncommanded yaw movement, not inside looking at the ASI.
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Absolutely. I never looked at the ASI. I listened to the sound of the wind over the windshield, and the venturi stall warning - which is better than the electric ones because it cries then SHRIEKS as the stall approaches - when it shrieks, you're approaching one limit, and when it's back to crying you're approaching the other limit.

And 5 degrees is about right, any more than that and it starts to increase rapidly.
 
zaitcev said:
I asked because being a pre-solo student and an inept one at that, I can never recover from a power-on stall in less than 450 feet. Usually it's 500. Our practice area's ground is about 6200 ft MSL, usual altitude is 7500 to 8000 feet. I was unable to find any guidance in AIM. FAR only has generic minimums in 61.119. FAA-8083-3A says to practice maneuvers above 1500 ft AGL.
-- Pete
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PTS says that the manuever must go no lower than 1500 AGL. So I'm planning on doing mine at 2500 AGL or higher for first timers, then lowering it down a bit for more experienced. I did a power-off stall and lost 400 feet, but to be honest I lost 100 before the stall by not maintaining altitude, and I let the nose fall too much by releasing more back pressure than needed to get the airplane flying again.
 
zaitcev said:
I asked because being a pre-solo student and an inept one at that, I can never recover from a power-on stall in less than 450 feet. Usually it's 500. Our practice area's ground is about 6200 ft MSL, usual altitude is 7500 to 8000 feet. I was unable to find any guidance in AIM. FAR only has generic minimums in 61.119. FAA-8083-3A says to practice maneuvers above 1500 ft AGL.
-- Pete
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What are you flying, Pete?

Some airplanes break significantly once the stall occurs, others seem to mush.
 
TMetzinger said:
PTS says that the manuever must go no lower than 1500 AGL. So I'm planning on doing mine at 2500 AGL or higher for first timers, then lowering it down a bit for more experienced. I did a power-off stall and lost 400 feet, but to be honest I lost 100 before the stall by not maintaining altitude, and I let the nose fall too much by releasing more back pressure than needed to get the airplane flying again.
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Tim -- a good training technique that helped me get over the big altitude loss was power around 65% stalls with only pitch changes for entry and recovery -- it's truly eye-opening to see how small a difference there is between flying and not flying.
 
TMetzinger said:
What's interesting here is that there really can't be a &quot;specified&quot; speed in a number for this manuever. Your speed in the turns WILL be higher than in the level flight segments - it's probably within that 10 knot margin, though. And the &quot;book&quot; stall speed is only a sanity check, not a target, as individual airplanes can vary based on rigging and loading. I think that the specified speed is just above aerodynamic stall - and the envelope translates to &quot;if you stall, you bust. If the stall warning stops - you bust&quot;.

Whatever the ASI shows really doesn't mean anything. Keeping the ball centered is more important, especially with manuvers that really kill people, like skidding turns to final.
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zaitcev said:
I asked because being a pre-solo student and an inept one at that, I can never recover from a power-on stall in less than 450 feet. Usually it's 500.
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If you were my student, we'd probably be working on improving those numbers -- I can't think of any light trainers where that much altitude loss would be considered "a minimum loss of altitude appropriate for the airplane"e (to quote the PTS). And the reason that's really important is that most power-on stalls occur at very low heights during departure while someone's trying to "horse" it over an obstruction.


Our practice area's ground is about 6200 ft MSL, usual altitude is 7500 to 8000 feet. I was unable to find any guidance in AIM. FAR only has generic minimums in 61.119. FAA-8083-3A says to practice maneuvers above 1500 ft AGL.
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That's good guidance there in the Airplane Flying Handbook, and the potential for a mistake to result in a spin is why it's recommended.
 
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Trapper John said:
Whatever the ASI shows really doesn't mean anything. Keeping the ball centered is more important, especially with manuvers that really kill people, like skidding turns to final.
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And looking at the ball is not the best way to handle that -- external visual cues and "butt feel" are. Since the same physical principles which move the ball affect the feeling of being pushed one way or the other in your seat, this is the one area where "seat of the pants" feel is just as good as the instrument. OTOH, staring at the ball is a good way lose track of other really important stuff outside, including other aircraft.
 
I recently have done manuevers during slow flight and today power on and power off stalls. During slow flight I could only make VERY shallow banks (5 degrees +or- a couple of degrees) and the stall warning was blaring the whole time. On the stalls, the instructor kept me going till the "buffeting" occured. We were at about 4300 AGL. I also lost too much altitude on the power on stalls. I definitely need more practice!

This thread popped up at the perfect time for me! I get feedback and never even had to ask a question! Thanks guys! :thumbsup:
 
SerArris said:
I recently have done manuevers during slow flight and today power on and power off stalls. During slow flight I could only make VERY shallow banks (5 degrees +or- a couple of degrees) and the stall warning was blaring the whole time.
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Good -- that is as it should be.

On the stalls, the instructor kept me going till the "buffeting" occured. We were at about 4300 AGL.
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That's a start, but eventually you'll have to take it all the way to the "break" to pass the PP flight test.

I also lost too much altitude on the power on stalls. I definitely need more practice!
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Yup -- that's the way to get to Carnegie Hall!
 
I think his point yesterday was the importance of keeping the plane coordinated and how going into a stall uncoordinated could be disastrous. He did demonstrate the "break" though.
 
This is an interesting topic to me because I busted my first checkride by losing to much altittude during flight at MCA. I lost ~400' flying with full flaps and trying to maintain the stall horn blaring - clearly a bust.

I got lots of practice between that and my second checkride (which I passed easily).

On my first practice flight after the bust (in a C-172) I didn't stay coordinated and had the right wing drop in the incipient spin - which I recovered just fine. It really startled me though! We practiced with stall horn blaring and if I recall correctly IAS around 40 kts.

Now for the more interesting part. When I took the re-check the DPE insisted on 30 degree banks at MCA. I added power to allow this (which he was fine with). The plane really turns quickly with full flaps, slow speed and 30 degree banks, but that's what he wanted to see. Maybe he wanted that because MCA was where I had problems before? At any rate, after the recheck was over he said "I knew you could fly the first time, you just had your brain all wound up!"

John
 
SerArris said:
I think his point yesterday was the importance of keeping the plane coordinated and how going into a stall uncoordinated could be disastrous. He did demonstrate the "break" though.
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Well, maybe not "disastrous."

If the ball is slightly out of center you may have a wing drop one side of the other. In any trainer (Cherokee, C150/170 series) you have to really put in yaw to get it to actually spin.

If one wing drops the right way to recover is to use rudder to "pick it up."
 
jsstevens said:
When I took the re-check the DPE insisted on 30 degree banks at MCA.
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I'd be curious to know what version of the PTS requires that -- not one with which I am familiar. I've never heard of an examiner demanding more than about standard rate turns, which is about 5 degrees of bank in most light planes.
 
I wonder if the DPE had already determined the task was passed once MCA was achieved in level flight (where he'd had the problem before) and was using the steeper banks as a way of building confidence - see, it CAN be flown like this!
 
TMetzinger said:
I wonder if the DPE had already determined the task was passed once MCA was achieved in level flight (where he'd had the problem before) and was using the steeper banks as a way of building confidence - see, it CAN be flown like this!
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That would be a violation of FAA Order 8900.2, and if an accident resulted, the DPE's head would be on the FAA's chopping block.
 
Ron Levy said:
That would be a violation of FAA Order 8900.2, and if an accident resulted, the DPE's head would be on the FAA's chopping block.
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Right - we all know DPE's NEVER give ANY instruction on checkrides:rolleyes2: (at least until the debrief, where they're supposed to).
 
TMetzinger said:
Right - we all know DPE's NEVER give ANY instruction on checkrides:rolleyes2: (at least until the debrief, where they're supposed to).
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Where's that written? I can't find anything in 8900.2 about a post-flight debriefing during which instruction is supposed to be given.
 
Ron Levy said:
Where's that written? I can't find anything in 8900.2 about a post-flight debriefing during which instruction is supposed to be given.
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I'll find it, it was in something I was reviewing yesterday that stated that the debrief should be given in a positive manner, clearly indicating the tasks that were not completed satisfactorily and what the error was. And then it went on to say the examiner should debrief the CFI in a non-criticizing manner. Somewhere in there there was wording that said that instruction was forbidden during the test but guidance could be given as part of the debrief.
 
Ron Levy said:
I'd be curious to know what version of the PTS requires that -- not one with which I am familiar. I've never heard of an examiner demanding more than about standard rate turns, which is about 5 degrees of bank in most light planes.
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Mine did on my PP and Comm rides.

During the Private practical, it was the first time I'd exceeded 15 degrees of bank that slow.

On the comm I'd been prepared by an excelent CFI that stressed the importance of slow flight mastery.
 
dmccormack said:
Mine did on my PP and Comm rides.

During the Private practical, it was the first time I'd exceeded 15 degrees of bank that slow.

On the comm I'd been prepared by an excelent CFI that stressed the importance of slow flight mastery.
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First time I had too. But I did it, and safely. And boy does that thing turn at that speed and bank!

John
 
TMetzinger said:
I'll find it, it was in something I was reviewing yesterday that stated that the debrief should be given in a positive manner, clearly indicating the tasks that were not completed satisfactorily and what the error was.
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Different issue. Yes, the examiner is required to explain what you failed and why you failed it. However, there is no requirement to instruct the applicant on how to do it.

And then it went on to say the examiner should debrief the CFI in a non-criticizing manner. Somewhere in there there was wording that said that instruction was forbidden during the test but guidance could be given as part of the debrief.
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"Could" isn't "should."
 
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TMetzinger said:
What you say seems inconsistent:
What I have had students do during slow flight is what I was hinting at earlier -- "ride the buffet."
I consider that a little too close to the stall since any increase in angle of attack or load factor will induce a stall.

So - do you have them ride the buffet or not? And if the standard is that any increase or load factor will induce the stall, why is that "too close"?

What I guess I'm getting at here is how close to the stall should I go?
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Since we are talking about beyond the PTS, I consider "riding the buffet" a mastery maneuver, e.g, at the commercial level. One rides the buffet wtih the RUDDER. Here we allow for the wing pickup with rudder in which we are a smidge unco-ordinated, right at the brink of stall.

When the wing drops, you ARE in stall. This is definitely not part of the PVT PTS. But to master the Stall recovery to Comm standards, it's much easier to do if you are comfortable with riding the buffet with RUDDER.
 
I had a student today with 50+ hours of time with previous instructors. He's a really nice guy and a good fellow to have for a student, but his slow flight skills were pretty sad. I don't fault him at all at this point, I think it has more to do with the quality of instruction previously given. Stalls also scare him. I wish I didn't have to undo things.

Ryan
 
I flew with a gal in her STOL C-182A, she was still a Student Pilot at the time. I asked her to demonstrate slow flight, she slowed it down to 65, that's what her retired airline pilot CFI was having her do. I showed her what it really looked like. You could get the nose of that plane so high the pitot would have stall issues and was reading absurdly low to nothing... Next try she copied just fine, "I didn't know it would go this slow..." "Yep, now hold this attitude pull some power and make that runway and see how short it'll land too."
 
Henning said:
I flew with a gal in her STOL C-182A, she was still a Student Pilot at the time. I asked her to demonstrate slow flight, she slowed it down to 65, that's what her retired airline pilot CFI was having her do. I showed her what it really looked like. You could get the nose of that plane so high the pitot would have stall issues and was reading absurdly low to nothing... Next try she copied just fine, "I didn't know it would go this slow..." "Yep, now hold this attitude pull some power and make that runway and see how short it'll land too."
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Yup. C-182N will still be flying when the ASI reads less than 40mph (which is the lowest number marked on it). CAS is much higher though, stall is 58mph CAS at gross.
 
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