Spiral dive

[FenderManDan]

In recovery from the spiral dive, I have been thought to cut the power first to idle and then level the wings.
I don't know to me it seems like it is the waste of time even those 1-2 sec, why not level the wings first and than cut the power to idle, ease out of dive.

Cheers,

Dan

[costermonger]

The reason you pull the power first is to stop gaining airspeed (or at least slow down the acceleration, depending on the attitude).

If you level the wings and then pull the power, your airspeed will be higher when you're starting to raise the nose than it would be if you do the recovery the way you've been taught.

[Beefitarian]

It must be fairly typical to wonder about this, I know I have. The bank of the spiral most likely is not super tight. It's the speed that will hurt the plane, especially when we need to ease the nose up to stop the dive. Any extra speed is going to cause more G force.

Vocalise it, "Throttle to idle, wings level, ease the nose up to a climb attitude. Then add throttle to maintain cimb power once you've converted some air speed to height and the plane has slowed down."

Don't tell your instructor but you have two hands, you will probably be able to pull the throttle and level the wings at the same time. I know we want to reduce the power as soon as we notice it's a dive to stop acceleration under power like costermonger said.

Hopefully these ones will result in some good conversations and not much fighting.

[T-roper]

why not do both at the same time?

[FenderManDan]

why not do both at the same time?

Recently, I was teaching someone to drive a standard transmission equipped car and while for me it is a simultaneous automatic reaction between a clutch and a gear change, for a new person it has to be explained in steps. Heck I can change gears sync'ed with no clutch.

Now back to flying. It is essentially that is what I will be doing but the sequence of things and why while teaching is what is interesting to me and take on that different folks have. That's all.

[akoch]

Left hand on the stick levelling the wings, right on the throttle pulling it back. I'm not an experienced guy, but it just happens automatic without thinking.

[Big Pistons Forever]

If you can,t level the wings and reduce power at the same time you have no business in an airplane. The important thing is to level the wings before you raise the nose If you have the terrain clearance. If you are close to the ground you may be forced to do a rolling pull out so you need to understand that you can not just yank the wheel back you need to be smooth and progressive with the pitch up.

Personally I treat spiral dives like spins. The most important part of the lesson is not how to recover it is how not to get that bent out of shape in the first place. Getting into a spiral dive means you have Fucked Up. You put on a bunch of bank with out controlling the pitch attitude. What should happen is you see you have let the nose drop and instead of tightening the turn with back pressure you roll out some bank, establish the proper pitch attitude and then roll in the bank again. Even if you are looking out the side instead of straight ahead you will feel the increasing pitch pressure so this should be your cue to fix things before the nose has dropped to far and you actually start a spiral dive.

[Doc]

Could we "dumb this down" any further?

Reduce/chop power.

THEN?

Level the wings.

THEN?

Ease out of the dive.
Little wonder folks are dyeing?

Should we have a check list for this? I don't happen to think this is anything but piss poor instructing. Altogether now....chop power WHILE levelling the wings WHILE easing out of your nose down attitude......ALL TOGETHER.......AT THE SAME TIME!
There are dead students at a well known aviation college, simply because a CLASS 1 "instructor" failed to recognize and IMMEDIATELY REACT to a spiral. These things can rip an airplane apart in flight, and recovery from same should not be taught as a "sequence" of events, but as a combined "reaction".

[Beefitarian]

Could we "dumb this down" any further?

Here you go.

[T-roper]

Could we "dumb this down" any further?

Reduce/chop power.

THEN?

Level the wings.

THEN?

Ease out of the dive

My personal favorite: Carb heat on THEN reducing power.

[c1lfw]

To the guys wondering about power idle before wings level: a windmilling prop is awesome for slowing you down. Power, level, pitch. PLP baby. (Terrain avoidance first, of course.)

[trey kule]

Doc, you got it so right...

The spiral dive is the most dangerous thing you will learn as a student pilot..
Now the good news...Recognition and recovery is so simple....throttle to idle.,, level the wings., pull out of the dive (gently if you are near Vne). The ground is not the only danger. Left to develop, the spiral will overstress the aircraft and make recovery impossible.
The TC FTM has the procedure illustrated simply.. Why do you people try to make it so complicated?
Carb heat on first? Fire the instructor that teaches that little bit of wisdom..
As to bank angle, Beef, I dont think you maybe understand what a spiral is. It is not just a simple descending turn.

[Beefitarian]

I think I do but since I only fly C-172s I will accept any criticisms.

In my opinion the reason a spiral dive is so dangerous, is the fact that it's so mundane that there is a Rediculas yet very real potential to either.
A- overspeed the plane by the time you recognize it. Or possibly worse..
B- simply have your head inside, programming some piece of equipment or doing paper work instead of flying the plane. Never noticing until you crash.

A shallow decending turn is exactly as dangerous as your "real spiral dive" in the case of B. In fact, you may be less likely to notice if the speed does not increase much.

Spiral dive during flight training? "Pfft, puhleeze," no Instructor has ever come close to surprising me with a spiral dive even with my eyes closed, because they enter it too quickly and at the time I could not figure out a way to avoid paying attention to what the plane was doing.

Even under the hood, instructor, "Here's an unusual attitude.. Ok, recover." Me while possibly yawning or rolling my eyes because it was so painfully obvious even with attempted distractions and lack of visual clues what direction the turn was. Pull the power, level the wings, ease the yoke back to transition the dive to a climb. Throttle up once the plane has slowed down.

The sheer boredom of the exercise was distracting to the point of wondering if the instructors were kidding. They couldn't be because they all did it the same, yet...

Even with a head set you can hear the plane is going too fast. A better trick would have been to put it in a regular level dive, you might have a moment where I'm confused as to which way to level the wings.

The problem is planes end up in a spiral dive or shallow decending turn when you're the sole pilot thinking you could never accidently enter a spiral dive. You are not controlling/paying attention to what the plane is doing. We can't imagine doing something leading to that happening and that is why they are so dangerous. They will only happen because basically no one is controlling the plane.

That should do. Time for people to tell me I'm dumb and this post is "painfull to read".

[trey kule]

ahhhh.. my eyes...my eyes...the pain, the pain

Seriously though, there is a huge difference between a shallow descending turn an a spiral dive. Spiral dives are dangerous if you do not recover properly, which, as you said, is painfully easy, but the lesson should be learned in the bank angle is excessive and speed is building rapidly that you cant just pull back to recover.
I will leave it at that.....

[Cat Driver]

the lesson should be learned in the bank angle is excessive and speed is building rapidly that you cant just pull back to recover.

Actually recovery can be accomplished after the wings break off, recovery will be immediate upon striking the ground.

[vcollazo]

Remember, it's very important to level the wings before pulling. If you pull up while rolling, you'll be subjecting the wings to an asymetrical load. Depending on your roll rate and pull, one wing could be subjected to twice the G load that you feel.

[Colonel Sanders]

it's very important to level the wings before pulling

True, and it's more than just the wings that you are stressing - you are twisting the entire fuselage, which is a torsional load.

Couple of terms. Ultimate G is when it breaks (eg +9G) and Design G is less than that (eg +6G). For a torsional load on the airframe, as a rough rule of thumb you want to drop your G down to 2/3 of the Design (eg +4G). Of course, the POH/AFM is golden in this respect (but is often silent).

As stated above, level the wings before the pull. This is also true of spin recovery, which also often results in a pitch-down attitude with bank on.

This has come up before, but just to annoy the straight-and-levels here, I might mention that I routinely recover from a vertical downline at 500 AGL by using full throttle, to minimize my altitude loss in the recovery. See Vg diagram.

[Big Pistons Forever]

Remember, it's very important to level the wings before pulling. If you pull up while rolling, you'll be subjecting the wings to an asymetrical load. Depending on your roll rate and pull, one wing could be subjected to twice the G load that you feel.

I disagree; what is important is to avoid breaking the aircraft. There are 2 ways to break the aircraft, pull the tail off (that is actually what is more likely to fail first, not the wings) or smash the aircraft into the ground. If you are in dumb enough to actually ignore the clear signs of a developing spiral dive and have lots of altitude then yes, of course, level the wings while reducing power and smoothly raise the nose. However if you are a commercial pilot and get into an inadvertent spiral dive at low altitude I would hope that you had enough training to be able to recover to straight and level flight with a rolling pull out without over stressing the aircraft.

The spiral dive should IMHO be taught like the spin recovery. The emphasis should be on recognizing and avoiding the situation in the first place and if you are dumb enough to get into one, apply the control inputs appropriate to the situation, which could very well include a rolling pull out. If the only objective of the exercise is to pass the flight test then mindlessly applying the formula, power to idle, level the wings, raise the nose will do the job. However if the objective is to produce a competant commercial pilot then I think a discussion of what you may have to do to survive is in order.

It is too bad trainers don't have Gee meters as knowing what 2 Gees feels like is a very valuable thing to know, as if you stay at or below 2 Gee you pretty much can't break the airplane. You can however demonstrate what 2 Gees feels like by performing a level coordinated turn at 60 degrees of bank angle........

[cgzro]

If altitude loss is your primary concern pulling power and/or pulling with wings not level will increase your recovery.

If G is your primary concern then rolling and pulling adds more G than leveling wings first.

Thats the physics as I understand it.

[iflyforpie]

This has come up before, but just to annoy the straight-and-levels here, I might mention that I routinely recover from a vertical downline at 500 AGL by using full throttle, to minimize my altitude loss in the recovery. See Vg diagram.

That is for an aircraft that is limited by energy and not G. Most of what we are flying and recovering from spiral dives is G limited long before we run out of energy.

[cgzro]

That is for an aircraft that is limited by energy and not G. Most of what we are flying and recovering from spiral dives is G limited long before we run out of energy

If you are worried about exceeding the G limit you sure as hell better not be rolling at the same time because you will likely exceed the rolling G limit which is always lower. i.e. 2/3rd or perhaps less.
http://www.pprune.org/flight-testing/37 ... imits.html
There is no case that I can see where rolling and pulling at the same time gives a better result than rolling to put the wings where you want, stopping the roll and pulling.
Roll/stop/pull limits the G (so less stress), It limits the turn radius(so less chance of hitting the ground -especially when combined with full power), It limits the time in the pull(so limits the speed build up).

[Big Pistons Forever]

There is no case that I can see where rolling and pulling at the same time gives a better result than rolling to put the wings where you want, stopping the roll and pulling.
Roll/stop/pull limits the G (so less stress), It limits the turn radius(so less chance of hitting the ground -especially when combined with full power), It limits the time in the pull(so limits the speed build up).

For a Pitts Special with a 360 deg/sec you are probably right. However your average high wing Cessna has maybe a 40 degs/sec roll rate and leaving the aircraft in a significant nose down attitude while waiting for the aircraft to roll level before introducing any pitch up will consume some altitude, altitude you may not have. My only point is that at the FTU level there seems to be this idea that any kind of rolling pull out will automatically cause you to over stress the aircraft, something that is simply not true.
At the CPL level I think it is entirely appropriate that a student know that they may in fact have to do a rolling pull when faced with a low level spiral dive situation and they must be cognizant of the fact that the positive pitch rate must be managed to avoid over stressing the airframe

But I return to my initial point. The thrust of the spiral dive exercise during training should not be how to recover from a spiral dive , although that needs to be covered, instead the emphasis should be on recognizing the precursor conditions that will lead to a spiral dive and arresting then before things get so bent out of shape that you actually need to recover from a true "spiral dive".

[Colonel Sanders]

your average high wing Cessna has maybe a 40 degs/sec roll rate

Everyone overlooks it, but roll rate is a function of airspeed. A Cessna might roll at 40 deg/sec at 50 knots, but at 150 knots it's going to roll a hell of a lot faster. Roughly, the ailerons are going to be 9x as effective, at 3x the airspeed.

In fact, they are powerful enough at high speed that you can cause damage with full aileron deflection. You're miles past Va, of course. Again, that damage may be a cost you are willing to pay, to avoid hitting the ground. Better to have wrinkles in the wings and fuselage, than splattered over the ground.

In decades of flight instruction, I have never had a problem with 172 aileron authority in rolling level before pulling, after either a spiral or spin. The reason people hurry the process (and do a rolling pull) is that they are panicked. There is not a lot of rational thought going on at the moment.

This has been the cause of many airshow accidents in the past, and I am sure will kill many more newbie airshow pilots, who panic in a vertical downline at low altitude (eg after a tumble) and snap-roll their way to their death because of their panicked and fatally-flawed recovery. Youtube is full of videos like that.

People will talk endlessly here about how cool they are, but all their logic goes out the window when the windscreen fills up with ground.

[cgzro]

For a Pitts Special with a 360 deg/sec you are probably right. However your average high wing Cessna has maybe a 40 degs/sec roll rate and leaving the aircraft in a significant nose down attitude while waiting for the aircraft to roll level before introducing any pitch up will consume some altitude, altitude you may not have. My only point is that at the FTU level there seems to be this idea that any kind of rolling pull out will automatically cause you to over stress the aircraft, something that is simply not true.

Here is how I see it:

A) If we roll the wings level before the pull then we 'waste' say 1 second but after that 1 second we have 100% of 6G's going into lifting the nose. For arguments sake we'll use your 45 degrees a second and assume we are 45 degrees banked. Lets also assume a 6G ultimate +G limit.

B) If we instead Roll & Pull but at 2/3rd the 6G (otherwise we break things), so 4G but now we are turning too which is gonna burn up at least a 1.5G for the turn component perhaps a bit more so we end up with only 2.5G's actually lifting the nose! I.e. we've traded 3.5G of our nose lifting potential for wing leveling....was that a good trade?

So the comparison you want is the resulting radius difference between a 1 second delay followed by 6G pull, or an 'N' second application of 2.5G's followed by 6G.

So .. whats 'N'

[Big Pistons Forever]

For a Pitts Special with a 360 deg/sec you are probably right. However your average high wing Cessna has maybe a 40 degs/sec roll rate and leaving the aircraft in a significant nose down attitude while waiting for the aircraft to roll level before introducing any pitch up will consume some altitude, altitude you may not have. My only point is that at the FTU level there seems to be this idea that any kind of rolling pull out will automatically cause you to over stress the aircraft, something that is simply not true.

Here is how I see it:

A) If we roll the wings level before the pull then we 'waste' say 1 second but after that 1 second we have 100% of 6G's going into lifting the nose. For arguments sake we'll use your 45 degrees a second and assume we are 45 degrees banked. Lets also assume a 6G ultimate +G limit.

B) If we instead Roll & Pull but at 2/3rd the 6G (otherwise we break things), so 4G but now we are turning too which is gonna burn up at least a 1.5G for the turn component perhaps a bit more so we end up with only 2.5G's actually lifting the nose! I.e. we've traded 3.5G of our nose lifting potential for wing leveling....was that a good trade?

So the comparison you want is the resulting radius difference between a 1 second delay followed by 6G pull, or an 'N' second application of 2.5G's followed by 6G.

So .. whats 'N'

I am having trouble seeing how what is appropriate and necessary in recovering from a botched manoever in a high performance aerobatic airplane has anything to do with the question posed by the originator of this thread who is, I gather a low time pilot talking about the spiral dive in the context of flight training at an FTU. I mean in the scenario you described in a Pitts you would also have the option of continuing the roll inverted and pushing your way out of the dive, something that I would not try in a Cessna 150.

My only point is that the FTU cook book one size fits all "solution" to a flight control problem should at least be presented with some context.