R

rv72004

Well Known Member
The title is a bit misleading. Should read maintaining control whist stalled.

I learned something new the other day about controllability in a full stall. A veteran pilot showed me how to keep the stick full back [all the time] whilst in a upright stall and maintain wings level with rudder. We were descending at 2500ft/min with a indicated 70knots. Stick centered , full back , and plane was shuddering and bucking at the stalled condition. A very precise touch on the rudder pedals kept the wings level. [with him at the controls]

When I tried it, I would get into a over-control situation with rudder and then the plane would eventually flick in response to my inputs.
I never got it really right like he did , but got better.
What I realised is that I'm not a quick foot on the rudders as I thought I was.

The point is that rudder control in not given the practise it deserves. Just my humble opinion, but a quick reflex on the rudder could be a life saving asset.
Now let me go practise............
 
First off; if you were still "nose high", you were not stalled. When the wings stall, the nose will drop immediately. (well below 70kts in an RV-7)
Secondly, you are correct that at this point the wings should be kept level with the rudder only. In an aerobatic airplane any interaction with the ailerons at this point can cause the airplane to fall off on one wing and enter a spin.
 
This sounds interesting and likely something that I could not do without good instruction and practice.

What is the practical use of this skill?
 
rv72004 said:
.......controllability in a full stall.....keep the stick full back [all the time] whilst in a upright stall and maintain wings level with rudder. We were descending at 2500ft/min with a indicated 70knots. Stick centered , full back , and plane was shuddering and bucking at the stalled condition. A very precise touch on the rudder pedals kept the wings level......
Click to expand...
I believe this is sometimes referred to (at least in my local area) as the "falling leaf" maneuver. I often practiced it in my old C-150. Requiring a deft touch on the rudder pedals, it was easy once I got the hang of it. I should give it a try it in my -6A. I suspect the RV will be somewhat less forgiving of clumsy footwork though.
 
slow flight

If the airplane is stalled (don't think you actually stalled) the nose should drop through and it should recover and stall again if the stick is held full aft. It should continue the pitch ocilations until you hit the ground. Do you know how to recover from a spin? If you fail to keep the ball centered during these pitch ocilations you will enter a spin. It is good to undertand how your airplane flies in all corners of the envelope and even more important to know how to recover if it departs from controlled flight.

Chris M.
 
Christopher Murphy said:
If the airplane is stalled (don't think you actually stalled) the nose should drop through and it should recover and stall again if the stick is held full aft. It should continue the pitch ocilations until you hit the ground. Do you know how to recover from a spin? If you fail to keep the ball centered during these pitch ocilations you will enter a spin. It is good to undertand how your airplane flies in all corners of the envelope and even more important to know how to recover if it departs from controlled flight.

Chris M.
Click to expand...

I thought an elevator stall produced the nose-down condition in a tail plane. Why would the nose drop from a stalled condition in the main wings? I would think that a wing buffet and a descent of 2500 fpm goes along with a stalled condition, but they maintained enough forward speed to keep the nose up with a non-stalled elevator. Remember wing stall is related to angle of attack, not forward airspeed.
 
Waker yer feet up

If you do any aerobatic training one of the first things the instructor will want you to do is to "wake up your feet".

Precisely as others have said, the rudder becomes much more important in aerobatics.

Aerobatics gone wrong (also known as FUN above a certain altitude) almost always results in a spin.

Now you see where the waking of the feet is a critical skill. The RV has very good rudder authority and keeping the wings leel is actually pretty easy. It will also recover from fully developed spins..as shown here..

http://www.youtube.com/watch?v=TQIZQ2yti1Y

Health warning DO NOT SELF TEACH AEROBATICS!!!!

Frank
7a
 
Rick6a said:
I believe this is sometimes referred to (at least in my local area) as the "falling leaf" maneuver. I often practiced it in my old C-150. Requiring a deft touch on the rudder pedals, it was easy once I got the hang of it. I should give it a try it in my -6A. I suspect the RV will be somewhat less forgiving of clumsy footwork though.
Click to expand...

A couple of biannuals ago my instructor showed me the "Falling Leaf". The plane (6A) stalls, then recovers and stalls immediately and repeats this over and over again. The plane shutters, shakes and groans but I found it easy to keep the wings level with small rudder inputs. It seems a little harsher with full flaps, maybe because the airframe groans more. My wife does not like the maneuver at all!
 
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Dan Babenco said:
I thought an elevator stall produced the nose-down condition in a tail plane. Why would the nose drop from a stalled condition in the main wings? I would think that a wing buffet and a descent of 2500 fpm goes along with a stalled condition, but they maintained enough forward speed to keep the nose up with a non-stalled elevator. Remember wing stall is related to angle of attack, not forward airspeed.
Click to expand...
The nose drops in a stalled condition because the wings are no longer providing lift, i.e. stalled.
Yes, wing stall is a factor of AOA. However in a wings level, 1G stall, "stall speed" is pretty consistent.
 
Ron Lee said:
........what is the practical use of this skill?
Click to expand...
Some flight instructors use the maneuver (I had one) to encourage students to use their feet in a timely, coordinated manner and the falling leaf also serves to graphically demonstrate that when the ailerons become useless just how much authority the rudder can have.

Make no mistake...you enter the falling leaf like any other power off stall.....but you KEEP the stick in your belly at all times. From reading a few of the responses here, I get a sense that the "falling leaf" is not widely known. Prudence dictates it is unwise to practice without plenty of altitude and some prior instruction in spin recovery.
 
Ron Lee said:
This sounds interesting and likely something that I could not do without good instruction and practice.

What is the practical use of this skill?
Click to expand...

Good question! My guess it that it shows how to control the aircraft in this unusual flight state.
 
Mel said:
First off; if you were still "nose high", you were not stalled. When the wings stall, the nose will drop immediately. (well below 70kts in an RV-7)
Secondly, you are correct that at this point the wings should be kept level with the rudder only. In an aerobatic airplane any interaction with the ailerons at this point can cause the airplane to fall off on one wing and enter a spin.
Click to expand...

The nose was dropped and fully stalled , below 50 knots.
The speed seemed to pick up when the stick was held full back and balancing with rudder. With the shuddering going on, I think it was stalled.
 
Christopher Murphy said:
If the airplane is stalled (don't think you actually stalled) the nose should drop through and it should recover and stall again if the stick is held full aft. It should continue the pitch ocilations until you hit the ground. Do you know how to recover from a spin? If you fail to keep the ball centered during these pitch ocilations you will enter a spin. It is good to undertand how your airplane flies in all corners of the envelope and even more important to know how to recover if it departs from controlled flight.

Chris M.
Click to expand...

It was definetly fully stalled, stick stayed full back all the time. No oscilations. And yep I agree dont go do this on your own !! Not a manoever to be taken lightly.
 
Sounds normal to me

I thought this was standard training for a tail dragger pilot. When I transitioned from spam cans to a Champ in 1982 that exercise was the first thing my instructor had me do. Which BTW resulted in the engine quitting and the prop stopping. In an airplane with no starter (you can't dive fast enough in a Champ to turn the prop) that also resulted in a forced landing. Probably carb icing. It was after multiple exercises at idle. Our motors are not near as susceptible to ice as that old C-65 but it is just something to think about. Clear the engine every once and a while. Back to the exercise. IMHO it is a good exercise to learn aircraft control; particularly rudder usage.
 
Mel said:
The nose drops in a stalled condition because the wings are no longer providing lift, i.e. stalled.
Yes, wing stall is a factor of AOA. However in a wings level, 1G stall, "stall speed" is pretty consistent.
Click to expand...

Mel, I agree with you. My point was only that in order for the nose to drop, you have to lose the component of lift forward of the center of gravity such as main wing stalled, and you have to lose enough downward component of lift in the tail to be unable to compensate.
If you (carefully) increase AOA past the main wing stall during high-speed flight, you can keep the nose up, until the tail stalls.
I remember the first time I overcorrected from the nose-down attitude of a slow-speed stall. If you have enough airspeed, you can be in an accellerated stall...wings stalled, not flying, not producing lift, but nose going up not down.
 
"Walk-Down Stalls"

I think that what you're describing is more akin to a maneuver called a "Walk Down Stall" rather than a true Falling Leaf. In a Falling Leaf (at least the way I was taught it way, way long ago), you let the airplane deviate from a straight course a bit, then catch it and send it the other way to the same amount on the other side as you went out on the first. You repeat as long as you keep the airplane in this condition. In a Walk Down stall, the intent is to keep the airplane right on center - no deviation - by using the rudders - hence, you are "walking" the nose down with your feet as it drops, daring the airplane to spin.

Doesn't address the "is it stalled or not" question - just a little trivia from the deep recesses of an older mind....:rolleyes:

Paul
 
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Falling Leaf Potentially Dangerous

In the F/A-18 A/B/C/D the Falling Leaf was a pretty nasty condition that was always guarded against especially in high-alpha AOA maneuvering - like ACM. In it you could see very high swings in both airspeed and AOA, and while the jet probably wasn't technically stalled continuously, it took some time to force a recovery or 'break' from the oscillations in and out of being 'stalled'. The NATOPS said it "may develop up to 20,000 fpm descent rates and can take up to 30 seconds for recovery after proper inputs." With a common hard deck of 10,000 AGL it's easy to see how this resulted in more than a few ejections or fatal mishaps. Here's a excerpt from test performed by Patuxent River investigating this condition:
AOA HANGUP I FALLING MODE
The airplane exhibits a weak nose-down pitching moment capability in the 45 to 55
deg AOA region which is further reduced with an aft CG and/or external store loading.
An AOA Hangup mode has been exhibited with these conditions where AOA stabilizes
in a high positive or negative region and roll, yaw and pitch oscillations develop with no
sustained rotation in one direction. This mode may be encountered during departure
recovery, during the final stages of spin recovery, or near zero airspeed (vertical)
maneuvers. Recovery from an AOA Hangup requires full forward or aft stick to maintain
full nose down stabilator deflection until sufficient pitching moment can develop to break
the AOA. A much more dynamic version of the AOA Hangup ih the Falling Leaf mode,
which may develop during any highly oscillatory departure and may be encounzeret. over
a wide CG range. This mode exhibits cyclic oscillations in roll, yaw and pitch wis,;t AO,.
ranging from approximately -5 to 55 deg and airspeed indications from 48 to 200 KCAS.
Recovery from the Falling Leaf Mode requires sustained application of full forward stick
to maintain full nose down stabilator throughout the oscillation to break the AOA.
 
Quite similar in 6A

I've done something such as that, in my RV6A also. I was going for a power off stall, with just me in the airplane. Power was off, the nose was high, and stick was full back.......... but it just mushed downwards with a high rate of descent. Lost about 1500' before I pushed the stick forward, which easily brought it out of this condition. I may have added power too, just don't remember, as it was a year ago.

I've had all my aerobatic training ( and rudder pedal work), including recovery from inverted spins in a Pitt's S2B years ago, so I wasn't much worried about it.

And P.S. due to the F-18 reply. My 6A is nose heavy, and requires at least a light pilot to be within the CG limits. Hartzell C/S & heavy starter motor.

L.Adamson --- RV6A
 
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Practical use of this skill

One practical use of this skill is that it conditions you to pick up a wing with use of the rudder rather than the aileron. When slow, and the wing drops, it should be second nature to pick it up with the rudder. This skill will also help you avoid spins.

Mike Draper
N468RV
RV-8 TMX0360
Finishing, punch list is getting shorter
 
Once upon a time I took a PA28-140 up to 8,000 feet and stalled it.

I rode the stall down to 3,000 feet keeping the wings level with the rudder.

I remember passing a commuter airliner while I was going down and he passed off my right wing.

Next time you fly, try doing "boxes on the horizon". It is a great rudder exercise.
 
Champ

cguarino said:
When I transitioned from spam cans to a Champ in 1982 that exercise was the first thing my instructor had me do. Which BTW resulted in the engine quitting and the prop stopping. In an airplane with no starter (you can't dive fast enough in a Champ to turn the prop) that also resulted in a forced landing.
Click to expand...

I've done this many times in my old Champ. I have stopped the prop in the air many, many times. I could always restart the engine in the air by diving to red line. (Maybe my compression was lower than yours!) It would slowly rotate against the compression, go past top dead center and stop on the next compression stroke. The next rotation would be faster and after about four of these it would start right up.

you wouldn't want to try that below 1000ft AGL tho!:eek:
 
Interesting thread!

Last week, I was getting "checked out" in the right seat of my plane - just because. I had a friend in the left seat, a 2000+ hour RV pilot (and also, as of last week, a CFI!). Anyway, we did some stalls, the usual, clean power off, clean power (some at least) on, flaps, etc.. We were at about approach power, perhaps 10" or so, full flaps. The plane went into the type of stall described in the first post of this thread. Stick full aft, airspeed something like 50, sinking like a rock, nose a bit below the horizon. It shook just a little during this, but I was able to keep the wings level with rudders. Of course, the goal was to actually recover, which I did after feeding my curiosity a bit. Of course, I had to make the correct hands do the correct things!

I've stalled this plane hundreds of times, but don't recall getting that reaction before. Neither did my friend. No strange loadings, seems like we might have had 18 or so gallons on board, plus about 380 lbs. of us. I didn't have the usual road kit (12 lbs) that I like in the baggage area.
 
Not an option

mannanj said:
I've done this many times in my old Champ. I have stopped the prop in the air many, many times. I could always restart the engine in the air by diving to red line. (Maybe my compression was lower than yours!) It would slowly rotate against the compression, go past top dead center and stop on the next compression stroke. The next rotation would be faster and after about four of these it would start right up.

you wouldn't want to try that below 1000ft AGL tho!:eek:
Click to expand...

I didn't have a 1000 ft.
 
n5lp said:
I'm trying to figure out how any RV could be in a full stall and indicating 70 knots at a stabilized 1g; and this is BELOW stall speed?
Click to expand...

Could have been due to rate of descent ?? It is possible I misread the GRT ASI but doubt it.
Also a stall is a function of AOA not ASI.
 
Check that airspeed indicator. I fly my 6A at 75mph in the pattern. Need a little power on round out to make it smooth.
 
rv72004 said:
Could have been due to rate of descent ?? It is possible I misread the GRT ASI but doubt it.
Also a stall is a function of AOA not ASI.
Click to expand...

That is correct - but exceeding the stall AOA at 70 knots will not happen in a 1 G environment.

Beyond all that, what is the point of descending like a falling leaf?

Seems like we go aloft to fly, not fall like a falling leaf. The maneuver is dangerous and pointless IMHO. Time would be better spend practicing recognizing a full stall and then recovering from it so as not to have it happen when not practicing it.
 
Andy_RR said:
Google G-FORS and AAIB and have a read before you have a go at this manouvre...
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For the lazy amongst us:

Report name: Slingsby T67C Firefly, G-FORS
Registration: G-FORS
Type: Slingsby T67C Firefly
Location: Near Potterspury, 6 miles northwest of Milton Keynes, Buckinghamshire
Date of occurrence: 25 May 2005
Category: General Aviation - Fixed Wing

Summary:

An instructor and his student were conducting a training flight when the aircraft was seen to enter a spin. The aircraft was still in a spin when it impacted the ground. There was no evidence of a mechanical problem; however, it is possible that the engine might have stopped during the spin. Whilst it was not possible to establish what the instructor planned to do on this flight, the investigation concluded that the aircraft probably entered an unintentional spin during an exercise involving oscillatory stalling. This particular exercise is not part of the UK Private Pilot?s Licence syllabus. As this exercise is considered inappropriate for ab initio flying training, a recommendation has been made to the CAA to ensure that flying instructors do not include oscillatory stalling during early flying training.
 
Mel said:
The nose drops in a stalled condition because the wings are no longer providing lift, i.e. stalled.
Click to expand...

Mel, a stall is simply separated airflow over the wings as I'm sure you're aware. Although lift does sharply drop off with separated flow present, the wings are still making lift even after stalled.

With sufficient elevator authority, the nose can be held up after the wing stalls. I could do it with my PA 28-180 (needed power-on) and with my RV4. The RV3/4/6/8, however, does have a very sharp stall break due to the airfoil and lack of washout.
 
David-aviator said:
Seems like we go aloft to fly, not fall like a falling leaf. The maneuver is dangerous and pointless IMHO. Time would be better spend practicing recognizing a full stall and then recovering from it so as not to have it happen when not practicing it.
Click to expand...
That's a good question. The falling leaf teaches you about the effect of rudder control in and near the stall. Practicing stalls with various rudder and stick inputs will help you recognize what control inputs will and won't yield a spin. So, in terms of flight training and profficency flights, the falling leaf is valuable and ranks up there with stall and spin training.

In everyday flying, the falling leaf isn't really useful. Sure, you could use it to loose altitude, just like a spin, but I don't think that's a great idea. Most RVers don't spend a lot of time around MCA. If you're flying a sailplane, you are spending a lot of time at or near MCA, so the use of rudder instead of stick is very important.

Now, for your last point, it's important for the pilot to see the airplane doing bad things (stalling, spinning, etc) and realize that they can recover and practice doing so. That includes imminent stalls, fully developed stalls, turning stalls, stalls that result in spins, spiral dives, etc. The falling leaf is just a way to understand the controllability you have with the rudder.

TODR
 
As far as the Firefly aircraft, that sounds like the aircraft used by the USAF Academy a few years ago that were involved in several fatal crashes.
 
Ron Lee said:
As far as the Firefly aircraft, that sounds like the aircraft used by the USAF Academy a few years ago that were involved in several fatal crashes.
Click to expand...

That's the one! Visitors to the last SWRFI out in Hondo, TX got to see lot's of them sitting lined up and rotting, prior to being chopped to pieces :eek: along with all of the readily salvageable 540's, constant speed props, radios, and instruments. :(
 
the_other_dougreeves said:
That's a good question. The falling leaf teaches you about the effect of rudder control in and near the stall. Practicing stalls with various rudder and stick inputs will help you recognize what control inputs will and won't yield a spin. So, in terms of flight training and profficency flights, the falling leaf is valuable and ranks up there with stall and spin training.

In everyday flying, the falling leaf isn't really useful. Sure, you could use it to loose altitude, just like a spin, but I don't think that's a great idea. Most RVers don't spend a lot of time around MCA. If you're flying a sailplane, you are spending a lot of time at or near MCA, so the use of rudder instead of stick is very important.

Now, for your last point, it's important for the pilot to see the airplane doing bad things (stalling, spinning, etc) and realize that they can recover and practice doing so. That includes imminent stalls, fully developed stalls, turning stalls, stalls that result in spins, spiral dives, etc. The falling leaf is just a way to understand the controllability you have with the rudder.

TODR
Click to expand...

Thanks for your point of view, it more or less covers what my friend was trying to instill on me. Most people dont do proper training before aerobatic flight. Flying aerobatics is even more dangerous if you are not 110% comfortable with what the plane is capable of, on purpose or inadvertently.
 
airspeed

n5lp said:
I'm trying to figure out how any RV could be in a full stall and indicating 70 knots at a stabilized 1g; and this is BELOW stall speed?
Click to expand...

Static and pitot ports (thus, airspeed indications) aren't accurate under the flight condition he is talking about. I suspect that his ASI may have been indicating 70 knots, but that wasn't necessarily his actual airspeed.

CDE
 
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