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-   -   Flat Spins in a BVM Bandit (https://www.rcuniverse.com/forum/rc-jets-120/11287599-flat-spins-bvm-bandit.html)

ravill 11-05-2012 11:27 AM

Flat Spins in a BVM Bandit
 
So I was doing my usual inverted flat spins in my Bandit. And then I decided to try to do it, right side up.

The damn airplane didn't want to recover!![X(]

When I'm doing them inverted, my Bandits (the Ultra Bandit is like this inverted) they recover really fast.

When I tried it right side up, the recovery didn't want to happen. I had to give opposite aileron and down elevator to recover.

Anyone else seen this phenomenon?

I figured the vertical stab stops the flat spin when inverted. When right side up, the vertical stab is in too much turbulence to be effective.

Hey, a right side up flat spin killed Goose in Top Gun! :(

http://i384.photobucket.com/albums/o...s/DSC_0303.jpg

http://i384.photobucket.com/albums/o...s/DSC_0305.jpg

http://i384.photobucket.com/albums/o...s/DSC_0357.jpg

dubd 11-05-2012 11:33 AM

RE: Flat Spins in a BVM Bandit
 
That was pretty spectacular to see.

highhorse 11-05-2012 12:06 PM

RE: Flat Spins in a BVM Bandit
 
Opposite aileron (lt in this case) typically enhances the spin rather than breaking it, as it (counter-intuitively) makes the outboard wing develop more lift while stalling the inboard wing more deeply. Then going "in-spin" (rt) would add drag to outboard wing, stall it, and slow the rotation, even as it "washes out" the rt wing and helps break the stall on that side. (If this seems confusing then remember that spins and snaps are conditions where one wing is stalled and the other is not) Ur spot on ref the vert stab being more effective while inverted.

Dn elev is ideally applied after the rotation stops so that you don't create an accelerated spin, but hey....

If your jet is in one piece then theory aside, whatever you did worked for whatever reason, and it's a good day !

Big props to you for doing more than the usual "whoosh, pull, repeat" typically seen with jets, thanks for sharing the great pics!

Don.

dbsonic 11-05-2012 12:20 PM

RE: Flat Spins in a BVM Bandit
 
Man, that is one nice looking Bandit!!!! : )

Where is your CG amigo?

asimace 11-05-2012 12:27 PM

RE: Flat Spins in a BVM Bandit
 
My Ultra Lightning recovers almost instantly both straight and inverted just centering controls...! (but I admit it doesn't look that good!)
Mauri

stuart_80 11-05-2012 01:25 PM

RE: Flat Spins in a BVM Bandit
 
Love the colour scheme..brilliant photos too

Stuart<br type="_moz" />

ollie witt 11-05-2012 01:35 PM

RE: Flat Spins in a BVM Bandit
 
Airliner horizontal stabilisers are usually positioned far behind the vertical stabiliser. If they are both positioned at the very rear of the aircraft, the horizontal can blank the vertical stabiliser in a flat spin and not allow the aircraft to exit the spin well. That would explain why your Bandit exits the negative spin fine but not the upright.

Those pictures are stunning though! Keep it up if you ask me :D

FalconWings 11-05-2012 01:51 PM

RE: Flat Spins in a BVM Bandit
 
I flatspin my BARF right side up, no issues on recovery. Have never tried it inverted, never thought it could be done. Now you have given me a reason to dust it off and fly it again.

John Redman 11-05-2012 02:04 PM

RE: Flat Spins in a BVM Bandit
 
Normally the Bandit and Kingcat/Bobcat airframes spin great inverted but have a hard time in the upright due to the washout in the outboard wing panels and the cusp at the fuse on the Kingcat/Bobcat. If you try an avalanche with any of these three models the model will begin the snap and about 65% of the way through the snap it will stop and then begin again. Do a negative snap in the avalanche and it will do it all day long. Recovery routinely is never an issue from either position.

ravill 11-05-2012 02:49 PM

RE: Flat Spins in a BVM Bandit
 


ORIGINAL: dbsonic

Man, that is one nice looking Bandit!!!! : )

Where is your CG amigo?
Oh, this is Darren! Ha! Thanks man!

My CG is BVM's.

I panicked when I saw that it didn't recover. After letting go of the sticks (it always recovers inverted), I waited, and waited and then panicked!!! I had to do something. I just input what I wanted the airplane to do, stop moving in the spin it was moving, and when it recovered, I just let go of the sticks again (for good measure). And continued a shaky flight!!:D

Luckily, I had enough elevation.

Hmmm, when I do avalanches, (I've always been more comfortable with inverted snaps), my bandits (big and little) have no problem with the snaps.

Here is a nice pic of an inverted flat spin (and then a smiley face! :) )


http://i384.photobucket.com/albums/o...s/DSC_0279.jpg

http://i384.photobucket.com/albums/o...s/DSC_0241.jpg

NickC5FE 11-05-2012 03:21 PM

RE: Flat Spins in a BVM Bandit
 
I think i was spotting for you and yes the plane took quite a while to recover. Killing that lift with aileron movement can definitely deepen the stall...see ya soon bruh!

BaldEagel 11-05-2012 04:48 PM

RE: Flat Spins in a BVM Bandit
 
The correct recovery from a spin is to centralise the aileron and apply full oposite rudder until the spin stops then apply down elevator, the full opposite rudder accelerates the inboard stalled wing and allows it to produce lift therefore start flying again, but if you still have aileron applied it will depart and enter an accelerated and sometimes inverted stall spin, anyway that's how I was taught to instruct it.

Mike

quist 11-05-2012 05:43 PM

RE: Flat Spins in a BVM Bandit
 
Maybe Ali will chime in and give you some advice.[X(]

Jim Cattanach 11-05-2012 10:40 PM

RE: Flat Spins in a BVM Bandit
 
I lost my Skymaster Viperjet to a flat spin. I had plenty of height, but nothing I tried made the slightest difference, till it hit the ground.

David Gladwin 11-06-2012 12:33 AM

RE: Flat Spins in a BVM Bandit
 


ORIGINAL: BaldEagel

The correct recovery from a spin is to centralise the aileron and apply full oposite rudder until the spin stops then apply down elevator, the full opposite rudder accelerates the inboard stalled wing and allows it to produce lift therefore start flying again, but if you still have aileron applied it will depart and enter an accelerated and sometimes inverted stall spin, anyway that's how I was taught to instruct it.

Mike
Then you were taught wrongly, potentially dangerous stuff !
Full opposit e rudder, pause, stick progressively forward until the spin stops !,
DG

highhorse 11-06-2012 01:16 AM

RE: Flat Spins in a BVM Bandit
 


ORIGINAL: David Gladwin



ORIGINAL: BaldEagel

The correct recovery from a spin is to centralise the aileron and apply full oposite rudder until the spin stops then apply down elevator, the full opposite rudder accelerates the inboard stalled wing and allows it to produce lift therefore start flying again, but if you still have aileron applied it will depart and enter an accelerated and sometimes inverted stall spin, anyway that's how I was taught to instruct it.

Mike
Then you were taught wrongly, potentially dangerous stuff !
Full opposit e rudder, pause, stick progressively forward until the spin stops !,
DG
No Dave. i know youre an aviation God and all but Mike has the recovery sequence right, if not some of the aerodynamics theory. Your method may work in some (or even most) aircraft but in others will will actually accelerate the spin and never lead to recovery. It's best to stop the rotation before breaking the stall, otherwise the outboard wing can actually translate from a semi-stalled condition to a fully flying AOA, develop more lift, accelerate the rotation, further increasing the efffective AOA of the inboard wing, stalling it more deeply which increases the rotation rate even more etc. (No need for popcorn folks, I'm not engaging Dave in further debate as he's proven to be completely intractable regarding these matters in the past)

David Gladwin 11-06-2012 01:43 AM

RE: Flat Spins in a BVM Bandit
 
Sorry, Highhorse, I WAS referring to BE's comment (only) but in the RAF we took spinning extremely seriously and at CFS we went into the theory and practice in very great detail. Based on my CFS training I taught it to other instructors (and students, some of Air Rank) at the Jet Refresher School where I was the senior flying standards QFI. Perhaps our RAF teaching was rubbish, I doubt it. Same recovery technique is taught in GA and gliding.

Sad you have to start making childishly silly personal remarks, adds nothing to your flawed argument about this but perhaps you should read the CFS notes on spinning. (enclosed). Anytime you want a robust, technical, intelligent , perhaps even cogent, debate based on professional knowledge, go ahead but leave the personal bit to the usual clueless keyboard warriors. Never fails to amaze me the complete bollox some guys write here. Keeping the stick back in a spin could well mean the spin stops only on impact. God help Bald Eagle's students (if he really IS an instructor) and god knows who taught him this dangerous nonsense.

Of course some aircraft DON'T respond well to standard spin recovery, eg Christen Eagle in which my friend Kraivuth of PST died in a spinning accident, (and some other aircraft such as some jets are often prohibited fron intentional spinning, Phantom Tornado, ) but the EE Lightning DID, even though the conservation of angular momentum with its high mass fuselage could somewhat delay recovery and initially speed up rotation, (many aircraft will intially speed up before recovery, due to that conservation of angular momentum, its a sign of the nose coming down as recovery commences !) but recover it would, using standard spin recovery. All you needed was height and lots of it.

Now read this, below, digest it, see the recovery technique for upright and inverted spins, and get back to me, and I'll tell the RAF, CFS and ETPS what they were doing wrong for all these years !! I'll pass on your comments and advice !

http://www.sssa.org.za/e107_files/do...7_spinning.pdf

Let there be no mistake, anyone who thinks they can recover a model jet from a spin by holding up elevator (in an upright spin) might just as well stand back and enjoy the inevitable crash.

Over to you !

Regards,

David.

HarryC 11-06-2012 02:19 AM

RE: Flat Spins in a BVM Bandit
 
In 30 years of flying full size gliders and full-size light planes, and regularly doing spins as part of my aerobatic routine, I have never heard of holding the stick back to recover except where specific aircraft designs required it. The standard recovery is always to start pushing the stick forward until the rotation stops. One exception I have personal experience of is the Robin 200 series in which I have done a lot of spins, the published technique is to hold the stick back and it is so unusual that in the UK the CAA requires a great big placard on the instrument panel warning the pilot about it! If highhorse and baldeagle are correct, why does the CAA think it so unusual that it requires a great big warning notice about it?

i3dm 11-06-2012 04:28 AM

RE: Flat Spins in a BVM Bandit
 
how do you enter a flat spin with a none vector thrusted jet ?

FalconWings 11-06-2012 06:13 AM

RE: Flat Spins in a BVM Bandit
 


ORIGINAL: i3dm

how do you enter a flat spin with a none vector thrusted jet ?
I enter by means of an avalanche. At the top I let it snap until it starts descending, let it get deep into a regular spin (on a BARF it takes about 2-3 spins), then start removing aileron and transition to opposite aileron......then watch it go flat. You need power all throughout, lots of elevator and full rudder. By the way this is for positive flat spin, for negative I have never tried it but I assume you would do a negative flat spin on the avalanche.
The key is to not loose inertia, otherwise you just stall.
I recover the same way Bald Eagle described, takes a lot of down elevator, and power.

BaldEagel 11-06-2012 06:36 AM

RE: Flat Spins in a BVM Bandit
 
David, please read my post again, no where did I say pull the stick back during recovery, we mear mortals do not inhabit the rarefied atmosphere that you frequent (or think you do), we read what is on the page and don't accuse others of talking bollox just because we have interpreted their post incorrectly.

Mike

FalconWings 11-06-2012 06:41 AM

RE: Flat Spins in a BVM Bandit
 


ORIGINAL: BaldEagel

David, please read my post again, no where did I say pull the stick back during recovery, we mear mortals do not inhabit the rarefied atmosphere that you frequent (or think you do), we read what is on the page and don't accuse others of talking bollox just because we have interpreted their post incorrectly.

Mike
Mike, don't waste your keystrokes on it. Do like Highhorse did, let it be. Eversince he was the first to brake the sound barrier his ego has turned unbearable. Oh wait a minute, wasn't that Chuck Yeager?
;)

Jack Diaz 11-06-2012 06:59 AM

RE: Flat Spins in a BVM Bandit
 
Raffi, "going to idle" and releasing the sticks always works for me. You have to react quick after the spin stops.
While maintaining full power the recovery is very difficult if not impossible.

I don't know the aerodynamical reason for this, but I am sure somebody here is going to explain it (probably between a couple of insults :D).
Enjoyed your company at BITW !

Jack

erbroens 11-06-2012 07:33 AM

RE: Flat Spins in a BVM Bandit
 

ORIGINAL: i3dm

how do you enter a flat spin with a none vector thrusted jet ?
It depends on the plane. Most jets have some offset in their thrustline so you can use for helping flatten the spin. Usually a deep stall on the proper side with some induced rotation and some thrust will do.

However I donĀ“t recommend to try this unless you have a backup jet for the next weekend flying session. ;)




dbsonic 11-06-2012 07:48 AM

RE: Flat Spins in a BVM Bandit
 
Always a good review. Was taught the NASA standard spin recovery and found a short blurb on wikipedia.

http://en.wikipedia.org/wiki/PARE_(aviation)

Now the F22 I think can challenge the conventional notion. It almost looks like it can just power its way out of it but it does look like the nose drops a little in the recovery. wild

http://www.youtube.com/watch?v=ML6pQ_6Lgf4


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