Effects of formation depth and aft sets

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Lawndart
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Effects of formation depth and aft sets

Post by Lawndart » Wed Oct 29, 2008 7:06 pm

A question often asked...

Q: Why can't I seem to hold my position even when the leader has constant power and/or constant G? He drifts away from me if I set the same power and G...

A: No wingman is flying the same profile as the leader (even if the leader maintains constant power, back pressure or G). Every wingman has an offset position and depth (even the Slot pilot). Let's look at a few scenarios:

For instance, when the formation apexes the top of a loop, the further back and the deeper a wingman is he'll need more power, speed and consequently less G than the Boss to "float" the top. It's important the leader be aware of problems like these faced by the wingmen, and provide them enough available power in the climb and apex of maneuvers. When the leader is pulling 1G over the top, the wingmen directly off to his side might be @ 0.8G's and the next set aft @ 0.5G's (same as Slot) and further back (Stinger) even more "float" and power required.

The outside of turns (high side) requires more power. The inside of turns (low side) requires a little reduction in power as you let the leader roll into you. Any pull requires a compensation in power and any "drive" or ease forward on the stick requires a power reduction to compensate for the unload. As you can tell there are many variables at play here, but the bottom line is remembering that any control surface input (elevator, aileron or rudder) adds drag, which necessitates a small power change to maintain position. Secondly, each position has a "stack" different from the leader, which means you're simply working (the entire time) to maintain that position off of him, but your flight path is never the same as his. Again, let me re-iterate that: At no time while in any formation, nor any position do you fly the same flight path and subsequently control inputs as the leader does (unless you were to fly "inside of" the leader's jet with collisions off).

Consider the pitch & power relationship for a second as well, since this has the greatest impact on your own power setting. For every time you pull back on the stick, you need to compensate with a bit more power to keep the sight picture solid. This is due to the fact that you're deeper and/or more aft than the leader, essentially flying a larger circle off of him. Anticipation is key. As any pull is begun, there's a tendency to go deep and aft (usually in that order). If this occurs, there will be a considerable power increase required to get back into position. The reason it's important to understand this is because even if you anticipate and remain in position, you still need more power than the leader by virtue of your offset. If you lag behind on the pull, it just makes it more difficult to get back into position. The catch is that you cannot start pulling before the leader does, so you're always anticipating, but constantly reacting to the sight picture which puts you slightly behind the power curve. Any of this sinking in yet? Keeping this in mind helps make it easier to maintain position with small throttle movements throughout every maneuver and turnaround.

Consider the the line abreast position for a second and you'll realize something. Your position is obviously abreast of the leader, at the same fore/aft set, and the same depth. You quite literally fly the same circle he does as long as you're able to hold your sight picture steady and mimic his control inputs and power changes as called. This actually makes the line abreast easier in comparison to other formations when executing pulls. (We won't go into why line abreast still is more difficult now, that's another topic). In other words, while in the proper line abreast position, you can fly the leader's control inputs closely matched in any pull without the need to compensate for any depth or offset other than the mistakes you make yourself in trying to hold the sight picture still.

At the end of the day, however, it's not your conscious awareness of exactly what inputs you are making that's important, it becomes second nature and subconscious rather quickly while all that matters is that you anticipate, fly reactionary and line up the appropriate parts on the leader's jet the entire time. He is your horizon and it doesn't matter what you see around him (upside-down, sky only or a milky mess in low weather conditions), you always want to have his jet in view the same way!

Turns also requires either a small amount of "cupping" or "toe" towards the center of the formation to maintain position. Without going into more details in this post about the effects of rolls and turns, here's a tip for flying an aft position (such as Stinger and even Slot to some degree): Always rudder away from the direction of turn as the aircraft ahead begin roll movement. As the roll is started, match roll rate and changing angle of bank and apply rudder opposite the direction of the turn to begin the pendulum effect. This goes back to the discussion earlier in this post about depth in the formation. Think about how an aircraft beneath the leader has to whip around the leader during turns, and it becomes clear why you simply cannot use ailerons (while keeping your wings perfectly level to the leaders attitude). If no rudder at all is used, Slot and Stinger need to "lag" their roll inputs and "cup" away from the direction of roll in order to maintain the centerline of the formation.

As always, remember to use rudder sparingly and smoothly!
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Post by Joker » Wed Oct 29, 2008 8:12 pm

Amazing post! At least now it's settled so when newcomers ask about this we can redirect them to this link. :) I actually learned a bit in that post, in-depth details anyways. Thank you Lawndart.
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Blaze
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Post by Blaze » Thu Oct 30, 2008 12:35 pm

You should write "Formation Flying in Lock-On For Dummies" LD! :lol: I think it'd sell quite well! :wink: But great info thanks.
Design is all about finding solutions within constraints.
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Ells
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Post by Ells » Tue Nov 04, 2008 5:24 pm

Excllent info, thanks LD!
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Post by Bow » Mon Nov 10, 2008 7:44 am

I actually think I get what you are saying here... i.e it took a while to register. Does this mean that let's say I'm flying slot and we are going to do a loop, as slot position I have to make a bigger loop so there is less pull to actually sustain my position, but since the loop is bigger I have to add more power to stay with the boss since the distance I'm covering is bigger... am I even close? LOL
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Post by Blaze » Mon Nov 10, 2008 12:12 pm

You've got it. ;) Since you are stacked lower than the boss your loop will be slightly bigger, meaning slightly more power than boss. The pull will be the same though for all 4 jets.
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Lawndart
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Post by Lawndart » Mon Nov 10, 2008 1:42 pm

@Travo357, you got the right idea.

@Buster, if you want to be picky, slot doesn't pull quite the number the Leader does, but the difference is negligible.
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Post by Blaze » Mon Nov 10, 2008 4:07 pm

Lawndart wrote:@Travo357, you got the right idea.

@Buster, if you want to be picky, slot doesn't pull quite the number the Leader does, but the difference is negligible.
Picky is good. :wink:
Design is all about finding solutions within constraints.
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