What the Heck Wednesday - Flying Wing Spin of Death

This week on What the Heck Wednesday we have another video from Xjet and these guys are some of my favorites.

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Flying Wing Spin of Death

This week on What the Heck Wednesday we have another video from Xjet and these guys are some of my favorites. They are always entertaining and certainly an example of a club that knows how to have a good time at the flying field. It's a long video, but the crash we are highlighting happens right at the very beginning. The pilot climbs while doing some aerobatics and then cuts the power while pulling back into a loop. That's when it gets hairy and the recovery turns into an uncontrolled spin all the way into the ground.

What could he have done differently to save it and prevent the crash?

If you have a video of a weird or entertaining crash and would like to be featured on What the Heck Wednesday, please send me a PM with your submission.

Who STOL that RC plane? (34 min 56 sec)

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Sep 23, 2021, 06:38 AM
Registered User
Pity...
With a slightly conservative CG, all he'd need to have done was to shut throttle and let go of the sticks for a bit and it would have recovered on its own.
If his CG was aggressively aft, he didn't stand much of a chance in any event (he did say he tried to recover).
Sep 23, 2021, 10:24 AM
Balsadustus Producerus
Yeah, he was holding full up the whole time. You'd think that would make it recover.
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Sep 23, 2021, 02:07 PM
Registered User
Without a tail, one does not have the control authority to effectively recover from spins. One might get lucky and pull out after the spin changes to a spiral dive. This is assuming the plane has enough yaw-stability built into it. I would do aerobatics with a Zagi or plane with a tail.
Sep 28, 2021, 10:00 PM
Heath
"What could he have done differently to save it and prevent the crash?"
  1. Stop pulling back on the elevator.
  2. Push the nose down.
  3. Counter the rotation with right aileron.
  4. Pull back on the elevator to return to level flight.
He pulled back on the elevator all the way into the ground ensuring the plane never stop stalling.
Stall recovery is something you have to practice. Pushing the nose at the ground can be scary at first but with some flying wings it is the best way to get them out of a stall.

Nothing lucky about it. Pushing the nose down forces the plane into a spiral dive. Recover from the spiral dive by first stopping the rotation using ailerons then pulling out like any other dive. Spins and stalls with a flying wing are great fun as long as you have a little altitude.
Sep 30, 2021, 06:56 PM
Registered User
Also know as delta death spiral. Most deltas cannot recover. Given enough height I can recover from one with my Assassin, but it requires max throws to do so.
Oct 01, 2021, 12:57 AM
Registered User
Quote:
Originally Posted by wildnloose
Also know as delta death spiral. Most deltas cannot recover. Given enough height I can recover from one with my Assassin, but it requires max throws to do so.
It shouldn't take more than a couple of turns to recover. You may be flying with a CG that is too aft. Also, if you're flying without winglets you might consider adding small winglets to make yaw stability better.
I've found that nose down stick till both wings are flying and then gentle roll-out of the spiral dive will work with almost any flying wing that has a reasonable CG.
Just because it flew up until the spin, does not necessarily mean the CG is reasonable.
Oct 01, 2021, 11:49 PM
Registered User
Quote:
Originally Posted by nuteman
It shouldn't take more than a couple of turns to recover. You may be flying with a CG that is too aft. Also, if you're flying without winglets you might consider adding small winglets to make yaw stability better.
I've found that nose down stick till both wings are flying and then gentle roll-out of the spiral dive will work with almost any flying wing that has a reasonable CG.
Just because it flew up until the spin, does not necessarily mean the CG is reasonable.
I never understood this comment. I fly the cg where I want it, moving cg just to get out of a flat spin is not something I would not even consider. Not going to add winglets either. Dealing with the death spirals is not a problem for me.
Oct 02, 2021, 12:00 PM
Registered User
Quote:
Originally Posted by wildnloose
I never understood this comment. I fly the cg where I want it, moving cg just to get out of a flat spin is not something I would not even consider. Not going to add winglets either. Dealing with the death spirals is not a problem for me.
Umm, yeah, obviously you'll fly your plane any way you want to. And obviously you personally may know how to get your specific Assassin plane out of the spin - you said that clearly in your post.
I was simply imparting some insight about how to set up the airplane (yours and others) to help avoid spins in the first place and enable easier recovery if a spin does occur - not just for you and your particular case/airplane, but for other people who may be interested as well. After all, the thread is about spins.

How moving the CG forward helps in that respect is a discussion in its own right and is discussed at length in other posts (for anyone who may be interested). And of course it is a trade-off, as always.
Oct 12, 2021, 07:54 AM
The runway used to be longer
Mad_Mike's Avatar
If you go to 24:45 in the video you can see a passable landing.
Surprising for this crew.
Oct 20, 2021, 08:18 AM
Registered User
Here is my approach, based upon many years of designing, building, flying (and occasionally rebuilding?) flying wings. Do not hesitate, do these steps sequentially, with no pausing in between. Since I am talking about a typical flying wing (V, Plank or Delta), it is unlikely to have a Rudder function, so part of the standard spin recovery technique in full scale and model aircraft is left out here.

1. IF the plane has a stabilizer active, flip it to OFF. Otherwise, it will fight the rotation by inputting full Elevons in the wrong direction, thus locking in the spin condition.

2. Neutralize the controls.

3.Apply full DOWN Elevons and you also may have to apply full power, assuming this is a powered wing with some juice left in the system.

3. As soon as the nose drops below the horizon orientation, the rotation should stop.

4. As soon as the rotation stops, neutralize the controls, reduce power and gently pull out of the dive. Roll out of the rotation, carefully, as you don't want to simply crank into either a spiral dive or perhaps a spin in the opposite direction! Hope that you have something let between you and the ground!

This usually works. It has worked for me many times while thermalling a flying wing, where you are spending perhaps 90% of the flight circling at low speed, i.e., very close to at least entering an incipient spin.
Oct 21, 2021, 04:27 PM
Pro Hoarder
turbonut's Avatar
That plane !just let go of the sticks..it will fly out of the spin by it self.
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Oct 22, 2021, 01:24 PM
Registered User
As always, it depends on the wing. Some wings can come out of a death spiral. Some cannot.

I have a turbine jet that if you put it in a flat spin, just get ready to pick up the pieces. It will not come out of it, no matter what you try.
Oct 23, 2021, 01:34 PM
Registered User
Quote:
Originally Posted by wildnloose
I have a turbine jet that if you put it in a flat spin, just get ready to pick up the pieces. It will not come out of it, no matter what you try.
Hmm....
Consider if you were the pilot of a full scale version of such a plane.
Would you consider that a well designed airplane?
I know that I would consider it an extremely poor design.
I imagine that turbine jet is somewhat costly as well. One inadvertant spin and it's a total loss? I'd modify it so that it could recover from a spin - either with some configuration changes, if possible (like CG), or actual design changes.
But that's just my take...
Oct 23, 2021, 11:23 PM
Registered User
The jet, while costly, was a trainer jet. Thus on the cheaper side of jet flying. Regarding the jet, the manufacturer put out a warning against putting the jet in a flat spin. They said the elevator gets blocked and becomes ineffective in a spin. When I acquired the jet the manufacturer was out of business, and I never inquired info from any other source. A simple internet search and I found out all the info I wanted on this jet, including the flat spin issue. Of course that was after I had crashed it.

Regarding the wing that I cannot pull out of a flat spin, well after the 3rd time I just made sure not to put it in one. One of the other wings require you to have full rates on and full throttle to pull out. This is a combat wing so it gets put in a spin on a regular basis. I have another wing that gets out of a flat spin pretty easy.

As for the plane design, not too concerned about it. I set my cg on how I like to fly the plane, not to better(or eliminate) the flat spin of it.


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