Ok, back to the throttle inputs again. In "unloaded" flight you're working in a very small area on the throttle (or trying to at least). Once we start maneuvering it depends on the maneuver what kind of anticipated throttle change you'll want to do. Any loop requires a power up because you're flying a position more stacked than Boss'. Any roll, especially a roll away from you, requires a power up by muscle memory or you'll fall back and deep, and later on potentially further back as you correct your sight picture back up again. So, basically you'll want to keep feathering the throttle in small increments, and anticipate any "known power changes" in our maneuvers. Another good tip for throttle usage is that anytime you end up deep, the corrective action by pulling (pitch) requires more power, so the throttle and pitch often work in tandem during corrections (outside the scope of "pre-planned" technique that assumes the sight picture is being held). Too deep? As you pull back on the stick more, you should also (without thinking about it) add more power (in small amounts) and vice versa.
Aileron inputs are simple, always try to match your wings to Boss' and/or match (ratchet) his roll rate! Period. This means we'll have to look at other factors in a roll, for instance, when you're being rolled away from (as #2 in the Diamond 360), you'll need to anticipate more power, more pull and right rudder towards Boss. These three things occur quickly and deliberately, yet almost simultaneously, and need to happen without thinking about it. Then once the bank is set ("Pull Set"), start working the throttle in smaller increments and strive keep the wings maintained level with Boss'. Whenever you're being rolled into (as #2 in the PIR, Diamond Roll etc.) you'll need to anticipate a bit of float, right rudder towards Boss and a slight power back depending on how quick the roll movement is. Once the bank is set ("Pull Set" as in the PIR), start working in a very small area on the throttle and hold a wings level attitude to Boss' (he is your horizon).
Additional tip for aileron usage: During any roll movement away from you, you'll want to err on "over rolling" (i.e. cupping a small amount) initially on the radio command, before you ever see the need for it and by doing this "retain" the roll/sight picture. During any roll movement into you, you'll want to err on "under rolling" (i.e. cupping a small amount) initially on the radio command before you ever see the need and let Boss begin rolling into you and then "catch" the roll/sight picture.
To sum up so far. Throttle inputs and aileron inputs should be small, deliberate with plenty of anticipation and "matching". We'll take those two axes out of the equation for the next part of this discussion:
Rudder should (deliberately) be used into Boss. Think of it this way: Any time you rudder away from Boss, you're making a corrective action to fix your position whether small or large. During a turn, regardless whether it's away from your or towards you, requires some rudder to be bled in and it will always be towards the Leader. Let's look at the Diamond Roll for example: #2 drops down 1-foot prior to the roll, then on the roll command you'll want to let Boss begin his wing movement into you, bleed in a decent amount of right rudder (yes, I said right rudder even for #2 while we're rolling left) into Boss, float your stick, and power back a small amount. These are the initial and deliberate control inputs - and they change throughout the roll as you'll need a large power up when you transition from float to a pull on the backside as #2), but otherwise you're basically using the "cupping technique" in the very beginning, bleeding in the rudder input towards Boss, powering back ever so slightly and floating. Those are the crucial first inputs that happen by anticipation on the radio call. From the moment the roll rate is then established, you'll learn to hold the proper amount of right rudder input, hold the aileron input matched to Boss' rate (albeit ratcheting may be necessary) and basically FLY using a light touch on the stick to float until the backside when power and a float-to-pull transition occurs. This transition in pitch is the most difficult for #2 during the roll, but as we'll discuss in a second, where you'll earn your keep by using precise and steady pitch inputs.
This brings me to the final axis: Pitch. Your Y-axis is the work horse of formation flying, and the one input that cannot be easily described or dissected, because it is ever changing and requires a lot of practice. It's the one axis you're constantly modulating, even if it's done with very fine inputs.
Let me summarize what we've discussed so far before covering the Y-axis further:
- Throttle - Work in small increments, constantly feathering, and use anticipation for maneuvers that require power (such as loops) and/or roll movements away from you or towards you.
- Ailerons - Anticipate the use of "cupping" initially to your advantage and always strive to match Boss' rate (I'd say almost 100% of the time). In other words mimic what you believe Boss is doing with your own X-axis (and ratchet your inputs whenever necessary as the only "fix" - technique wise).
- Rudder - Anticipate to blend in rudder and remember, it is almost exclusively towards Boss that you'll be using rudder, regardless of direction of roll movement. Anytime you find yourself "toeing" away from Boss when watching a track, you'll have to ask yourself what caused you to be FUBAR? (Hint: This has to do with your other inputs, and most likely not matching your aileron inputs causing a stagnation/too fast rate of roll input compared to Boss').
- Pitch - Constantly being "modulated"... but this is also where the quote: "Steady hands" stems from. You'll need to be able to hold a smooth, yet steady pull, unload and re-apply pull without causing any noticeable PIO. There's only one way to describe how to achieve having such disciplined hands and it's through practice, and lots of it. This is also why your setup for your Y-axis (properly configured curve, poundage, seat position etc.) is crucial, and I cannot stress that enough! You need the tools to be able to achieve desired results. It takes a lot of practice to be able to pull (any amount) by sheer muscle memory, and thereby fixing ones position, "flying the wing" and holding a steady pull even as you're loading/unloading the jet, albeit unnoticeable to anyone else. (This may also be where you run the risk of getting carpel tunnel )!
This "isolation" technique let's you assign what your goal is for each axis, and in a way makes the throttle, ailerons and rudder stupid-simple, eventually putting the focus on the Y-axis or your pull. When the other axes are done by anticipation and/or pre-planned technique (depending on maneuver) and you're matching movements and rates, the pull is where you'll earn your keep and develop that steady feel for exactly how to FLY the plane in each instance whether it's smooth as butter or during a rough day with lots of "texture". In other words, you'll learn to control any type of PIO while maneuvering the jet around Boss', always remaining within your "bubble" and regardless of whether you or Boss might be having a rough day, this is where the practice pays off knowing the entire range of the Y-axis like the back of your hand, and being able to "modulate" its inputs to minimize movements and fly your position. It's the only axis you can describe as if you were actually "flying it", and not just matching or making anticipated and/or pre-planned inputs (at the start of maneuvering).
I hope some of this made sense! Formation flying is an art, and soon enough you'll do all these things without even thinking about it, and in essence move your hands and feet in a choreographed ballet of control inputs as your "world" (literally) revolves around the Boss.
Additional reading: Effects of formation depth and aft sets