Inverted stall

[Mtns2Skies]

just out of curiosity, How do you recover if you somehow stall while inverted?

 

[flyingcheesehead]

just out of curiosity, How do you recover if you somehow stall while inverted?

Are you talking sustained inverted flight (ie negative AoA), or stalling at the top of a loop or other positive-G maneuver where you happen to be upside down (positive AoA)?

In either case, of course, the simple answer is that you correct the control inputs that are resulting in the airplane exceeding either its positive or negative critical angle of attack.

 

[Mtns2Skies]

Sustained. Does that mean pulling back would reduce the AOA?

 

[Henning]

Sustained. Does that mean pulling back would reduce the AOA?

Correct.

 

[Teller1900]

Make the houses get bigger. Whatever it takes. But make sure you keep them in the front window, as you do.

 

[kyleb]

Point the nose down.

 

[Mtns2Skies]

Point the nose down.

Thats the answer I wanted! Thanks

 

[MSPAviator]

How do you recover from an inverted spin?

 

[RoscoeT]

How do you recover from an inverted spin?

Same as an upright spin...remembering the above noted concept.

 

[PittsDriver]

Sustained. Does that mean pulling back would reduce the AOA?

Does the wing know that it's inverted? A wing can be stalled at any attitude wrt the ground and at any airspeed because it only "cares" about AoA in regards to lift/drag.

The problem that pilots have recovering from inverted spins is that, if you're going to use anti-spin inputs (vs. the Beggs-Meuller "let go" or Finagin center the controls methods) you have to correctly determine which way you're spinning. In an inverted spin it's easy to look down at the ground and see the airplane spinning the opposite of the way that it is because you're looking aft of the point of rotation. You have to look out directly over the nose (which is where you should be looking anyway) to accurately determine the direction of rotation and step on the proper anti-spin rudder.

This and many other good reasons is why the best upset recovery methods don't have to be concerned with which way the airplane is spinning or if it's upright or inverted.

 

[AEROBAT]

To stop a spin you must first stop the yaw. I have found an easy way to recover from a spin is to remember to step on the "high pedal". When spinning the weather vane tendency will be to cock the rudder to one side therefore one pedal ends up being slack.

When you step on the high pedal you will break the yaw coupling, then it is a matter of recovering from the dive [if upright] or rolling level and recovering [if inverted].

The above may seem stupid as everyone practices spin recovery after deliberately entering a spin. If you nailed the left rudder to enter the spin you know to use the right rudder to initiate the recovery. If when entering a spin from a botched manouver like a hammer head or you get into a cross-over spin and not realize it you may be confused as to which way you are yawing especialy if you don't realize you are inverted.

As Pitts driver pointed out you have to look straight down the nose to determine the yaw.

I like the Beggs Mueller method best but it does not work for every plane.

 

[Jeanie]

The Beggs Mueller method does not work for the Super Decathlon that I fly. I went up w/ a friend and we did lots of inverted spins as practice for me in case I "fall" out of a maneurver and didn't enter the spin on purpose. We did the close your eyes hands in your lap feet on the floor thing so that I could open my eyes and then have to look at the nose and figure out which rudder to use for the recovery.

My way of seeing it is that I step on the rudder that is on the side behind the nose... nose going left - lots of ground "behind it" step on the right rudder. The slip skid ball is unreliable - do not even bother to look inside. Assuming you've entered the spin in VMC....

The rest of the recovery is the same - PARE - and in the case of the inverted spin the elevator "thru neurtral" means towards your body

Stopping an inverted stall also means - elevator towards your body or point the nose towards the ground. But, be sure to be in control and SLOW if you plan to do a split S - that's a whole other ball of wax.

 

[whifferdill]

The Beggs Mueller method does not work for the Super Decathlon that I fly.

Gene Beggs does mention in his book that the Super D does not recover a left rudder inverted spin using Beggs Meuller. In the Super D, have you tried the power off, neutral stick (aileron and elevator), and neutral rudder emergency recovery technique that works for the Pitts in all spin modes? Does not require figuring out which direction you're spinning and which rudder to push.

 

[Jeanie]

Gene Beggs does mention in his book that the Super D does not recover a left rudder inverted spin using Beggs Meuller. In the Super D, have you tried the power off, neutral stick (aileron and elevator), and neutral rudder emergency recovery technique that works for the Pitts in all spin modes? Does not require figuring out which direction you're spinning and which rudder to push.

~~~~~~~~ No, I haven't tried it yet as I had not heard of that as a choice to try till now

Next time I go up I'll make sure I have plenty of altitude and try it to see what happens.... I'll have to make myself wait though as I"m used to simply fixing the spin.

Side note: I was practicing the first time w/ my friend who's helping me learn acro when he's around and I was WAY UP HIGH..... he said "ya'know, you're gonna have to get used to being closer to the bottom of the box if you're going to compete" My response was "right now, I'm just in the learning to stay alive mode, I like to have plenty of room"
Of course at our altitude - field elev. of 4500 - the DA for where I was practicing was about 11,500 which naturally means that loops just don't happen well. Someday I'll fly down towards sea level and see how that feels

 

[AEROBAT]

But, be sure to be in control and SLOW if you plan to do a split S - that's a whole other ball of wax.

In my plane, Midget Mustang, it builds speed pretty quick going down hill so I like to be as slow as possible doing the split S.

However under 100 mph the roll is mushy so what I do is roll around 100 mph and a bit of forward stick as soon as I am inverted and wait for it to start to buffet then I relax forward pressure and let it drop through.

 

[whifferdill]

But, be sure to be in control and SLOW if you plan to do a split S - that's a whole other ball of wax.

A lot of folks are very tentative with the split S and try to get very slow before rolling and pulling. This doesn't make for a good looking figure, competition or otherwise. It differs a little among aircraft types, but in general, the fear of overspeeding or overstressing the plane during the split S is not warranted. You can enter the Split S with a decent amount of speed, but you need to load the airplane very quickly to a relatively high G load. If this is done, your speed at the bottom will not be excessively high. In the Pitts, if I rolled into the Split S at 120mph and immediately pulled to at least 4G, while steadily increasing the pull all the way through to 5.5 or 6G, I would exit faster, but not come close to redlining. You would need to be careful with RV or Midget Mustang types, but most aerobatic airplanes are not as clean as these, and the advanced monoplanes that ARE fairly clean have a higher G limit to compensate.

 

[AEROBAT]

A lot of folks are very tentative with the split S and try to get very slow before rolling and pulling. This doesn't make for a good looking figure, competition or otherwise. It differs a little among aircraft types, but in general, the fear of overspeeding or overstressing the plane during the split S is not warranted. You can enter the Split S with a decent amount of speed, but you need to load the airplane very quickly to a relatively high G load. If this is done, your speed at the bottom will not be excessively high. In the Pitts, if I rolled into the Split S at 120mph and immediately pulled to at least 4G, while steadily increasing the pull all the way through to 5.5 or 6G, I would exit faster, but not come close to redlining. You would need to be careful with RV or Midget Mustang types, but most aerobatic airplanes are not as clean as these, and the advanced monoplanes that ARE fairly clean have a higher G limit to compensate.

When I first started flying the Mustang I thought about trying to compete with it. After taking some lessons in an Aerobat and a Pitts s2b I realized it would be very hard to stay in the box with the Mustang. It does acro real well but at too fast an airspeed. I really liked flying the Pitts and have been looking for a decent used one.

 

[whifferdill]

When I first started flying the Mustang I thought about trying to compete with it. After taking some lessons in an Aerobat and a Pitts s2b I realized it would be very hard to stay in the box with the Mustang. It does acro real well but at too fast an airspeed. I really liked flying the Pitts and have been looking for a decent used one.

At first it might be hard to stay in the box with the Midget, but this is true of any pilot in any airplane just starting out...and also remains a challenge even after you have quite a bit of experience. I guarantee the Midget could fly the Primary or Sportsman sequence inside the box.

The Primary sequence for example - you don't want to enter the box at 220 mph before pulling for the 45 deg upline. Whether you draw a short line or a long one, you'll end up using a lot of box slowing down for the spin. Enter much slower. You can pull power on the upline if needed. Consider the placement of the spin the key maneuver in the Primary sequence. If you get it right, you shouldn't come close to going out of the box for the rest of the sequence. Remember, you only have to draw a perceptible line (for any figure) - the length and speed is up to you and will not influence your score. Staying in the box has much more to do with maintaining situational awareness and managing your position as required by the sequence, rather than anything to do with the airplane itself. You can draw a short line between maneuvers, or you can drive it across the box, bleeding speed if needed, for as long as you need to get in the right position for the next maneuver. This situational awareness takes some time to develop, since at first, it's all your brain can do go keep up the maneuvers alone...much less monitor your position as you fly the sequence and plan ahead to the next figures.

Also, in the Sportsman category, you can design your own Freestyle sequence (within a set of criteria) that suits you or your airplane better than the Known sequence that gets changed every year. You still have to fly the Known, but you only have to fly it once. Your second or third flights could be your Free.

 

[thomascannon]

In the lower tiers of competition, the penalty for going outside of the box is nominal. Sure, if you're hoping to compete at the higher levels, it might be worth re-thinking your airplane choice, but if you're just flying Sportsman, have at it! If you go out you'll lose a couple points, but really, who cares?

That said, if you get your hands on a nice Pitts and want to share it for, say, the cost of fuel, I'd be happy to borrow it whenever you're not using it....

 

[AEROBAT]

Yes...you guys have convinced me. I should go out and practice the known primary, I have a copy tucked in the journey log. After all it is just for fun!

 

[Jaybird180]

Does not require figuring out which direction you're spinning and which rudder to push.

Can the body sense the direction of motion? Is there a push or pull feeling like a skid or slip?

Sorry, I only have about 3 or 4 spins under my belt and its been awhile, so I don't quite recall if there was kinesthetic sensation or not - I was on brain overload the whole time.

 

[thomascannon]

Can the body sense the direction of motion? Is there a push or pull feeling like a skid or slip?

Short answer: no. Also, while inverted, you're tempted to look "up" (which is actually down) which will more than likely give you the wrong idea of what is going on. You need to look over the nose of the aircraft and then it's quite obvious which way you're rotating.

You can demonstrate this to yourself pretty easily. Sit in an office chair and spin in a circle while looking straight ahead. Really easy to tell what's going on. Now, spin while looking straight up at the ceiling. Sure, you can figure it out, but it's a lot harder. Add in some adrenalin and a whole lot of noise (inverted spins are really loud) and try to figure it out ... in a hurry.

 

[whifferdill]

Yes...you guys have convinced me. I should go out and practice the known primary, I have a copy tucked in the journey log. After all it is just for fun!

Awesome...and in Primary, there are NO penalties for going out, but presentation scores will suffer. And if you're so far out that they can't see what you're doing, you're not gonna get a good score on that figure.

Can the body sense the direction of motion?

Especially with inverted spins, the yaw direction (as viewed from the cockpit) is opposite the direction of roll, and it's easy for the roll component to dominate, which can lead you to believing you're spinning the opposite way.

 

[denverpilot]

Okay, I'll bite. Why are inverted spins louder than upright ones?

 

[n_a_spin]

Gene Beggs does mention in his book that the Super D does not recover a left rudder inverted spin using Beggs Meuller. In the Super D, have you tried the power off, neutral stick (aileron and elevator), and neutral rudder emergency recovery technique that works for the Pitts in all spin modes? QUOTE]


All of the Super Ds I have flown do recover with this technique. But it is far quicker to kick rudder. Beggs works most of the time but accationally require a little pull back off the forward stop in inverted spins.

BTW....I find the best way to know which rudder to kick is the one that is hard and close. The wrong one is soft and farther away.

Adam

 

[whifferdill]

Okay, I'll bite. Why are inverted spins louder than upright ones?

I've never noticed a difference in the planes I've flown, but I guess it's possible in some planes that the sound of the air hitting the plane at the angle and negative AOA associated with an inverted spin could be different from that of an upright spin.

 

[gismo]

Okay, I'll bite. Why are inverted spins louder than upright ones?

I suspect that perception is based on the fact that many inverted spins in airshows are purposely flattened by carrying significant power vs upright (and non-flat) spins are done with the engine at idle).

 

[PittsDriver]

Okay, I'll bite. Why are inverted spins louder than upright ones?

I'm gonna guess it's because when you're in mortal fear that all your senses become more acute

And, that's probably why Whiff hasn't noticed it - he's a steely-eyed fearless aviator that's been known to fly in those little biplane bugs.

 

[B2Soar]

Okay, I'll bite. Why are inverted spins louder than upright ones?

Its the volume of the shouting-screaming -cussing-whatever that gets louder when inverted.

 

[thomascannon]

The inverted ones have all the air banging at the same side of the plane that you happen to be located on. In a Pitts, the entire cowling over the nose is hammered flat from the air flow.

Upright spins are pretty quiet compared to inverted ones. Of course, hanging in the straps upside down in a falling airplane does catch your attention, so there might be some truth to that making it seem louder.

Maybe it's just me. Dunno.

 

[whifferdill]

The inverted ones have all the air banging at the same side of the plane that you happen to be located on. In a Pitts, the entire cowling over the nose is hammered flat from the air flow.

Upright spins are pretty quiet compared to inverted ones. Of course, hanging in the straps upside down in a falling airplane does catch your attention, so there might be some truth to that making it seem louder.

Maybe it's just me. Dunno.

Never even thought about or noticed noise...except for the cursing - that does make them louder I guess. All I've ever paid attention to is the ground and trying to stop on heading...hence the cursing. In my Pitts, stall/spin dynamics are very different inverted vs. upright. I'm still trying to get the entries, spin, and stops as precise and consistent as the uprights. Right rudder inverted spins in my Pitts are fairly slow, with the nose oscillating up and down a bit. Left rudder inverted spins have a more even rotation, and seem to rotate quite a bit faster within one turn...add in a little right aileron after the rudder is in and it approaches a slow snap speed.

 

[thomascannon]

I don't really have all that much experience with inverted spins, but I do know that every time I've done one in a pitts the nose oscillating thing happens every time. It takes at least a rotation and a half before it settles down. It seems like adding a touch of power helps flatten it out some. No idea what causes it but suspect that it's the apparent wind blowing on the top of the elevator, which then rises and spills the airflow, and then drops again into the airflow and then dumps again... finally finding some happy medium... eventually.

I like upright spins a lot more. Less headaches from both the blood in your head and from trying to figure out how to fly a plane with the controls all working backwards from how you'd expect.

Also less cursing.

 

[whifferdill]

I don't really have all that much experience with inverted spins, but I do know that every time I've done one in a pitts the nose oscillating thing happens every time. It takes at least a rotation and a half before it settles down. It seems like adding a touch of power helps flatten it out some. No idea what causes it but suspect that it's the apparent wind blowing on the top of the elevator, which then rises and spills the airflow, and then drops again into the airflow and then dumps again... finally finding some happy medium... eventually.

I like upright spins a lot more. Less headaches from both the blood in your head and from trying to figure out how to fly a plane with the controls all working backwards from how you'd expect.

Also less cursing.

I would imagine you're doing inverted spins with right rudder, since if you're also playing flat spins, it's the only way it's gonna happen. I think, as you describe, the relative wind of the plane before it settles down into a vertical trajectory causes some oscillation. It's exacerbated by using right rudder, which causes the gyroscopics to pull the nose skyward. It's similar to an upright spin using left rudder. In the Pitts, upright left rudder spins oscillate more within 2 turns than right rudder spins. And right rudder uprights, and left rudder inverted spins will rotate more nose down and steadier until the spin fully develops (2 turns or so). I guess this only really matters as it relates to competition, since you'll never do more than a 1 1/2 spin in this case. Of course we have to be able to do everything equally well both ways, and I've got a bad habit of only practicing different maneuvers in one direction.