Extreme nose-high unusual attitude recovery

[Hedley]

A (three star retired) air force general asked me a question the other night, and apparently I was one of the few people whom have ever answered it correctly:

Q: From an extreme nose-high attitude, what angle of bank is optimal for recovery?

Hint: 99.999% of pilots will get it wrong

[Bushav8er]

180

[CCnCoke]

0° angle of bank - it's pitch you need to worry about.

[FlaplessDork]

90

[PunkStarStudios]

So what's the answer?
0 seems too obvious.

[Blakey]

Too little information to give a rational answer but I would lean towards 180 as the answer. (It depends on whether you still have any lateral momentum or not.)

As an aside, I´ve been in the Air Force for 31 years now and only ever met one Lt Gen who could fly worth a s**t so I wouldn´t take anything this one said as gospel just yet. Luckily, the one who could fly is our current CAS!

[paydaymayday]

90 degrees. Then you let the nose fall (almost like a hammerhead), and after you're below the horizon, it becomes more like an overbank recovery.

[iflyforpie]

Bank angle becomes more and more of a moot point the higher nose-up you go.

If I still had a close horizon to work with, I would put the aircraft knife edge (90 degrees) and let the aircraft do a ballistic arc. The wings aren't supporting the aircraft, the tail is keeping the plane aligned with the airflow, all you do is just wait for the horizon to pass in front of you (and probably let A/S build up a bit too).

[Flying Low]

I'm going with 90....that's what is taught on the RJ. Seems to work well in the sim.

[Hedley]

90 degrees - basically, a hammerhead - is a fascinating answer - I personally am quite fond of that maneuver - but it's a bit risky for a couple of reasons. If you don't hold the vertical perfectly during the pivot, it is very easy for a spin to develop - the wings are seeing very different AOA. Also, because you are pivoting, there are polar moment of inertia problems with the yaw wanting to continue. See spin concerns above. If you have enough airspeed to wingover, it's a neat choice, albeit a bit sporty, potentially.

So the other obvious choices are:

0 degrees of bank - pushing through from the vertical to wings-level upright - or,

180 degrees of bank - pulling the nose down from the vertical to wings-level inverted

From an AOA standpoint, which is a better choice? Remember, the wings do not have eyes, and cannot see the attitude of the aircraft, only AOA.

[niss]

180 degrees of bank - pulling the nose down from the vertical to wings-level inverted

From an AOA standpoint, which is a better choice? Remember, the wings do not have eyes, and cannot see the attitude of the aircraft, only AOA.

Methinx this is the one, it goes naturally with the airplanes goal of going up. We are upside down but with a negative AOA the airplane thinks it is climbing. Except this is one of the rare times the airplane can climb into the ground.

[AuxBatOn]

I say 180 AoB, pull with max lift (just before critical AOA) until the horizon, then roll upright (point roll). Quickest, most efficient to get out of an extreme nose high unusual attitude.

[niwre]

are you the first Canadian this "3 Star General" has asked?

[Bushav8er]

If you are at 45 degrees AOA in an upright position (relative to the earth), you'd have to push through 90 degrees to get what '180' would give you 'instantly', plus less loading and neg Gs, and you're in a position to trade altitude for airspeed.

[old_man]

I have been taught to go inverted and roll level once through/at the horizon (basically what auxbaton said).

Here is a better question, what do you do with the throttles in a piston single when you find yourself in that position? (I am not saying I have the right answer)

[North Shore]

Wouldn't it be simpler to try to just avoid the situation in the first place? You are now replacing one unusual attitude with another, but more (IMHO) complicated, because you are inverted..

[GoinNowhereFast]

throttles in a piston single

Every single I've flown only had one throttle.

I think first question is too vague to give a straight answer. It depends a lot on airspeed, power available and, of course, angle.

In a 172, much more than 75 degrees up, and I'd say just pull and roll level on the other side. Although, then ask, what the hell were you doing 75 degrees nose up in a 172!

Now, what I'd do with the throttle, push it to the firewall.

[Bede]

Hedley,

Are you saying you're extremely nose up or vertical? I'd go 90 in any aircraft I've flown. You and auxbaton fly stuff that will actually go vertical, so I would assume you'd know. Maybe if I was actually vertical, I'd pull level, than roll.

BTW, I don't like your explanation about possible spin entry. Even though you are near vertical, your AOA is not past the critical angle once the maneuver is started, hence no spin threat. Forgive my lack of aero experience, but in every sim I have done this maneuver in (MU2, CL65, B737), I've never been close to a spin, or a stall for that matter at the top of the maneuver. (I've done this in small GA planes, but I'd get fired if I did this on the Boeing)
On that note, it is interesting to do this maneuver in an aircraft (or sim) with a checkerboard stall indicator on the A/S tape. You are only doing 90 kt's while falling, but the stall speed checkerboard shows 60 kts stall; this is because of the decreased load factor. Once level, you increase load factor back to 1, and immediately enter a deep stall (50kt's below stall speed).

Great thread though.

[erics2b]

BTW, I don't like your explanation about possible spin entry. Even though you are near vertical, your AOA is not past the critical angle once the maneuver is started, hence no spin threat. Forgive my lack of aero experience, but in every sim I have done this maneuver in (MU2, CL65, B737), I've never been close to a spin, or a stall for that matter at the top of the maneuver. (I've done this in small GA planes, but I'd get fired if I did this on the Boeing)

Look up the coined term "Hammerspin".

[iflyforpie]

I wrote my 90 degree response with this caveat...

Bank angle becomes more and more of a moot point the higher nose-up you go.

Nose high to me is 45 degrees. At this attitude, I am doing more of a wing-over than a hammerhead.



But if I am above 45 degrees in a light GA aircraft:

1) I am going to have a tough time locating the nearest horizon and...

2) I am going to have an even tougher time maneuvering in relation to that nearest horizon as airspeed is decaying.



So I figure it is a trick question for bank angle. Maintain neutral roll inputs and pull. The answer could be 0 (before going over the top), 180 (coming over the top) or anything in between if your nose doesn't go right through 90.

Why pull? Aircraft is stressed for it better. Positive AoA. Most aircraft will give better pitch rates up than down. The key is to locate the horizon and go from there.

Even though you are near vertical, your AOA is not past the critical angle once the maneuver is started, hence no spin threat.

Yes, a plane only stalls with excessive AOA, but it needs to be maintained that way.

You could reduce your stall speed to zero by flying a ballistic arc close to the ground. But you can't fly a ballistic arc forever and if your airspeed is too low (still not stalled) you wont have the stability, control authority, or energy to recover from the maneuver.

Same with hammer heads. A perfect hammerhead is a zero AOA maneuver. But to keep it zero AOA is harder than it seems. Since the wings are going different speeds, you need to put a ton of opposite aileron to keep you from going inverted. We want to have the aircraft pointed straight down so it will be aligned with the airflow going downline.

So what will happen with zero airspeed, yaw, and roll? Your aircraft will tumble and now your zero AOA is a very large AOA with miminal airspeed and autorotation.

Sounds like a spin to me.