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Formation Flying: Station Keeping

Posted By: EinsteinEP

Formation Flying: Station Keeping - 02/28/12 09:39 PM

I created this simple mission to practice straight and level station keeping with an AI Lead. Not as fun as a human flight partner, but much more reliable and forgiving! wink

www.2gvsap.org/einstein/attach/FormationPractice.zip (unzip, don't just rename!)

In this mission you are air-spawned off the wing of an AI A-10C that is flying a rectangular route (WPs 0 through 3) at a constant altitude and airspeed. The rectangle is 20 NM by 10 NM so you have plenty of time between waypoints to practice station keeping and cross unders. The AI will continue to fly this rectangle in a loop until it is bingo fuel.

I strongly recommend reading up on formation flying before attempting it here. Paulrkiii has a fantastic guide that I will link to (when I get permission and find a working link!), in the meantime, here are some pointers:
  • For close fingertip formation, aim for about 45° behind the lead with some wingtip separation and stack down. See the sight picture below to see what Lead's aircraft should look like when you are in position.
  • When joining up, first get on the right angle back, then close distance to lead along that line until you're in position.
  • You are never in formation. You are always making corrections to get into formation.
  • Anticipate power and control input changes before you need them so you are always making small corrections, not large ones.
  • Smooth and steady on the inputs. Large, jerky motions scare Lead and just makes your position problem worse.
  • Tiny changes in throttle make big differences, but it takes time to see the effect. Be steady and patient, but stay on top of it before you get far out of position.
  • Behind too far ahead (aka "acute") is much more dangerous than behind too far behind (aka "sucked"). Don't do either.
  • NEVER turn belly up to Lead!
  • If the only way to stop an overrun is to turn belly up to Lead, DON'T! Descend and coast under Lead, slow down and fall back behind Lead, then creep back up into position.
  • You are making rate changes with your controls, not position changes. If you find yourself wildly oscillating (up/down, left/right, or back/forth), STOP! First make the rate of change stop, then slowly scoot into position.
  • Work on station keeping first, then try cross unders to switch sides.
Note: The AI plane flies straight and level nicely, but makes some wicked hard turns. Watch your TAD and don't get caught too close on the inside of a turn!



Sight picture for A-10C parade formation: wingtip on the ejection diamond, near engine exhaust lined up with far engine cowling.
Posted By: - Ice

Re: Station Keeping practice - 02/29/12 09:01 AM

Thanks Einstein! What does "turn belly up on lead" mean?
Posted By: tomcat

Re: Station Keeping practice - 02/29/12 11:56 AM

Roll so you lose visual?
Posted By: T}{OR

Re: Station Keeping practice - 02/29/12 01:14 PM

Just the thing I was looking for. Thanks!

The AI is really bad for formation flying unless flying straight and level.

Here is my contribution: USN Fundamentals of Formation Flying video.

This is not about A-10, but the basic principles apply here. Have a look at our DBS formation flying fundamentals THREAD.


I like the line "You are never in formation. You are always making corrections to get into formation." smile


Originally Posted By: - Ice
Thanks Einstein! What does "turn belly up on lead" mean?


Always keep the leader in sight.
Posted By: EinsteinEP

Re: Station Keeping practice - 02/29/12 04:18 PM

Originally Posted By: - Ice
What does "turn belly up on lead" mean?

See responses above.

Sometimes, when joining up, an over eager student will not recognize they have a high closure rate on Lead until too late. The instinct is to sharply bank away (i.e. turn belly up on Lead) but in doing so the Wingman loses sight of Lead, creating a very dangerous situation. The proper response is, instead, for the Wingman to pass underneath Lead in a calm and controlled manner (i.e., "overshoot"), break out of formation, then rejoin with a little less enthusiasm.

The better response is to never have that high of a closure rate in the first place!
Posted By: GrayGhost

Re: Station Keeping practice - 02/29/12 05:52 PM

Yep, know how and when to break out ... for the when part:

Hazard - you have become a hazard to the formation
In front, above or under lead - you shouldn't be there
Told - you've been told to break out. Do it.
Sight - you're blind on lead/formation

Break-outs don't have to be and shouldn't be violent, and what you do depends on the situation at hand. The break-out really just means you're distancing yourself from the formation in a timely manner. No need to go crazy. If you are overtaking lead a little, fix it. If you're overshooting proper, call the break-out, pull away from lead a little, and climb a little. Don't go so crazy that both he and you go blind on each other - that's just one situation, others exist, just like the one EinsteinEP described.

Just always make sure your breakout is controlled, professional, and not excessive (ie. no need to break out 2-3-4-5nm for a 50kt overshoot).

Ask for the permission to rejoin after you have confrirmed safety of the flight, that those who need to see you do, and you see them, and rejoin in a timely manner.
Posted By: darkmouse

Re: Station Keeping practice - 03/02/12 03:07 PM

There is a perfect example of my wingman joining with too much enthusiasm in this vid at 2.12 and a controlled break at 2.50 - http://www.youtube.com/watch?v=p8Ykuhh4TwQ

He always tried to be too 'punchy' and #%&*$# blew it ever time!

Cheers,

Darkmouse
Posted By: T}{OR

Re: Station Keeping practice - 03/08/12 10:04 PM

Posted By: EinsteinEP

Re: Station Keeping practice - 03/09/12 02:58 AM

Well done, Thor! I'll let you fly my wing anytime! wink
Posted By: T}{OR

Re: Station Keeping practice - 03/09/12 10:02 AM

Thanks, I'll be glad to. smile Compared to IL2, this is much easier on the pilot. Probably due to higher fidelity FM.

I'll try to post some in cockpit shots next time around.
Posted By: MagnumHB

Re: Station Keeping practice - 08/12/12 11:22 PM

Plenty more where that came from. I've been flying formations with THOR for years now (although these shots aren't with him).



Posted By: Frederf

Re: Station Keeping practice - 08/14/12 07:29 AM

I have two major areas weakness with regards to formation flight.
1. I have a hard time differentiating from route and close spacing. Often I get much closer than I should.
2. I have virtually no practice with tactical forms.
Posted By: EinsteinEP

Re: Station Keeping practice - 08/14/12 05:34 PM

Frederf,

1. Me neither. The lack of depth perception and (in my setup, at least) perspective vision makes it uniquely challenging to maintain a consistent distance without frequent glances to Lead. Maybe that comes with experience? I'm hoping to learn.

2. Me neither. But then, I don't have much experience with real formation flying basics anyways. And by real formation flying, I mean station keeping with a sight picture, cross unders, extend trail chase, etc. - not just flying next to some other airplane.
Posted By: GrayGhost

Re: Station Keeping practice - 08/15/12 01:32 PM

For 1. you need visual references on the aircraft itself, maybe Magnum can provide them. And it's not 'frequent glances at lead' in these formations ... it's 'cross-checking instruments'. You stare at lead.

Tac forms are flown a mile apart, and the whole idea there is that you can now cross-check the wingman and concentrate either on visual look-out or instruments, whichever happens to be your particular task within the formation.
Posted By: Wrecking Crew

Re: Station Keeping practice - 08/15/12 05:02 PM

Originally Posted By: GrayGhost
Tac forms are flown a mile apart, and the whole idea there is that you can now cross-check the wingman and concentrate either on visual look-out or instruments, whichever happens to be your particular task within the formation.


^^^ Interesting stuff, as always GG.

Last night in Kojori we had a 3-ship formation and it would have been best had we decided on the way in who would TGP scan and broadcast SPI/SADL, along with other tasks. In fact we could have assigned a TGP scan to three pilots as we were flying into the tri-airport area around Tbilisi. And we were too close - well I sure was - to have been able to TGP and stay in formation. But we had a blast smile

WC

Posted By: GrayGhost

Re: Station Keeping practice - 08/15/12 05:40 PM

Having fun is the main goal smile
Posted By: DemonHunter

Re: Station Keeping practice - 12/04/13 06:10 PM

Thanks Einstein!!! Just what I have been looking for. I loaded up the mission last night. Pefect...now lots of practice
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