Aces High Bulletin Board
Help and Support Forums => Help and Training => Topic started by: Shuckins on June 19, 2002, 08:17:14 AM
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Mathman or AkDejaVu:
I have seen this move referred to in several posts about the Hellcat. Could one of you describe the correct method for utilizing this move? What is the correct distance from con on my 6 to initiate the move? What control inputs do I use to start the barrel roll? Do I cut throttle and drop flaps?
Appreciate any help you can give me.:)
Regards, Shuckins
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Would it be this move you are talking about?
Pic: - "Sudden application of barrel roll during a luring break turn to force overshoot"
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Kweassa,
That may be it. Can't tell from the diagram, but is that last move to bring guns to bear on trailing bandid a vertical move on his belly from underneath?
Regards, Shuckins
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Nice pic Kweassa :).
Shuckins:
Judging the attacker's e-state is pretty crucial in timing your defensive barrel roll. Distance to initiate a defensive barrel depends a lot on the relative energy difference between you and the attacker. For someone who's closing with a lot of smash you can begin your barrel roll with them farther out while someone who's closing at a moderate rate you want to execute the barrel roll with them closer in. As Lephturn likes to say, this is a sucker move and if the other guy is wise to it, you will end up in an even worse position. I've died plenty this way and it takes quite a bit of dying to learn how to apply this maneuver.
Tango, XO
412th FS Braunco Mustangs
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Sorry I'm late on getting in on this.
Let's talk about overshoots for a second.
There are two kinds...a 3/9 overshoot and a flight path overshoot.
A 3/9 (wingline) overshoot is caused by excessive closure. The attacker is simply going too fast and flys past the defender's 3/9 line.
The flight path overshoot is a turn radius issue. The attacker cannot match the defender's turn radius and consequently flys through it.
The defender can force a 3/9 overshoot by slowing down. He can do this one of two ways...one, simply chopping power and putting out drag...or, two, he can lose the speed by maneuvering hard to deplete his energy regardless of his power setting.
In the case of the latter (the maneuver technique), this type of maneuver is generally known as a "last ditch defense", usually against a gun attack. It's a last ditch attempt because the end result is that you are out of energy...the defense better have worked, because otherwise, you're in deep kimshi!
This maneuver comes in two types...the High G Roll Over The Top and the High G Roll Underneath. The two differ only in the direction of roll. The "top" maneuver is flown by rolling opposite the direction of turn (right turn, left roll)...and the "underneath" type is flown by rolling in the direction of turn.
Strictly speaking, these are NOT barrel rolls! They are a way of putting the brakes on aerodynamically.
In the example in question, it is debatable whether the Barrel Roll will provide the deceleration needed to force the 3/9 overshoot. In a defensive context, the Barrel Roll is intended to defeat a gun attack by making it difficult for the attacker to track the defender. The maneuver is an attempt to create an aiming problem, not a closure or flight path problem.
In any case, remember that the assumption is that the defender is pulling max G in the defensive turn prior to the initiation of the roll. He has no more G to provide an increase in turn performance...all he can do is rotate his lift vector (which is what the two last ditch maneuvers do). Any rolling maneuver such as a Barrel Roll in this situation will increase the defender's turn radius. The extent to which the roll depletes energy will be a function of the intensity of the roll...more G, more airspeed loss. At some point (as G is increased), this roll becomes the last ditch technique.
One point to consider in AH. This maneuver can be very disorienting for pilots that use snap views. If flown properly, the maneuver is not lazy. It is an aggressive, high G roll...this leads to problems with keeping the bandit in sight. In RL, when we used this maneuver, we gave up the tally momentarily to put max attention on the maneuver. Once the roll was complete, we then looked to where we thought the bandit would be. If we were successful, the bandit would be high, forward of our 3/9 line, and to the outside of the turn.
If not successful, all we had to do was check six!!
To sum it up...do not use this maneuver to force a turn radius (flight path) overshoot...it probably won't accomplish this. Use this technique to force a 3/9 line overshoot. If this is your goal, then don't popsiclefoot the maneuver. Regardless of which way you roll, keep the G at max as you roll. Your rate of roll will determine how much energy you lose...roll slower to lose more speed.
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Andy if i got you right the move i descripe now should be a flight path overshoot.
I got an bandit comin in from high or dead 6 and he is faster than me.
1st i roll about 45° to one side, than pull up (this will slow me down a bit and due to speed loss, reduce my turning circle and increasing speed difference to attacker). If i see attacker is trying to pull pure or lead and he is still rapidly closing, i immediately roll 180° (so i invert my lift vector) and pull max G back after the roll is complete (starting some sort of Split S).
As i am now going towards earth, i will accelerate and build up speed (reducing speed gap to attacker).
Next move depends on reaction of attacker. If attacker pulls off, i will usually complete the Split S till i speed away in the opposite of my orignal flightpath.
If attacker tries to follow the move down, indicated by him rolling and pulling after me. I will roll again 160-180° after i nosed down to about 45°, and than after the roll i will pull up (in so performing some kind of diagonal Split S).
Usually i end up on the six off the bandit as his speed took him across my flight path, as he could not match my turning circle.
Usually i get a shot opportunity. In this case i created a flightpath overshot right?
And if the bandit is all out trying to reverse again, i will be inside his turn and due to my slower speed will be able to follow him through. By using lag pursuit in this situation i often end up on the bandits dead 6 co-E or even with a little E advantage when the guy pulled to hard in his last reversal.
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Here's a diagram of what I understand you to be saying. Your question is "Is this a flight path overshoot?"
(http://webpages.charter.net/alfakilo/na.jpg)
Yes. And it is also a 3/9 line overshoot. Ultimately, more of the latter.
After all is said and done, what you are doing here is forcing the bandit out in front through a series of hard turns on your part. These turns commit the bandit to a nose low attitiude from which he cannot keep from over-running you.
Of course, all of this assumes the bandit will cooperate with this as it is happening! :)
But, we'll assume he does!
I don't advise pre-planned maneuvers that operate on the assumption that if I do this, he will do that, and then I'll do something else. Life doesn't work out that way.
Instead, the way it actually goes is that I'll do something that is BFM-appropriate given the starting positions of both aircraft. Then I'll watch for the bandit's reaction. From that reaction, I'll then plan my next move. Some folks liken BFM to chess. In a sense, that's true...but, it's also a little misleading. Good chess players try to forecast their opponent's moves in the future. In BFM, that kind of planning can get a person in trouble if he gets blinded by preordained assumptions and fails to react to events as they unfold.
A Split S is a good defensive move but it is hard to keep a tally on the bandit when flying it. With regard to sim flying (particularly in sims like AH where many folks use snap views), the view changing needed to move from position 2 to position 4 are considerable, assuming the player wants to keep a tally and not hit the ground too!
End game? You fly a series of hard reversals that causes the bandit to fly out front. At that point, you become the "chasee"!
One minor item. If you are at a lower speed than the bandit that you are pursuing, you use LEAD pursuit to catch up, not lag maneuvers. Lag maneuvers are usually flown when you have too much airspeed for a given situation.
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Thanks Andy.
And it is not that i assume a "coorperating" bandit, but many times it went like this and so i used this BFM-chain to describe.
And do i really use lead? I always use lag, pure and lead to describe if my gunsight is pointed aft, on or ahead of the enemies 3/9 line.
And when i usually come out of this move and attacker is using a split S i.e. i let my gunsight stay behind his 3/9 line, so i will conserve E or even build up E relative to him.
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Naudet
You've got it right!
I think I misunderstood what you meant.
In the situation you describe (slower speed but inside the bandit's turn as it maneuvers out in front of you), I suggest a Low Yo-Yo type of maneuver to gain energy and closure rather than lag pursuit.
The lower G that you have in lag will allow you to gain some airspeed back but a quicker, better solution to energy deficit in this example is a yo-yo (also known as "acceleration maneuver").
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I do a low-yo-yo in case of horizontal turning, but most often i will be inside of a Split-S performed by the attacker. And in this pure vertikal move i think i can only gain speed on him by laging.
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Naudet
Your comment about using a Low Yo-Yo in a horizontal situation points out an area that some folks may not understand.
Most A2A academic references show BFM from a level horizon perspective. This is for ease of explanation more than anything else.
What often is not explained very well is that BFM principles are meant to be applied to the three dimensional world where up and down or level flight have little meaning. Gravity is a constant that needs to be considered in any maneuver but we don't have to tie ourselves down to a two dimensional world to do that.
The technique that I teach in your example is "fly to the low wing"...in effect, expressing the concept of a "low yo-yo" in different words. This technique is a better idea of how to conserve or gain energy than the lag pursuit idea.
In most BFM applications, lag pursuit is used to avoid creating excessive angle off/aspect angle situations or to allow a poorer turning aircraft to maintain nose-tail separation on a better turning adversary...the lag concept has applications that directly address closure but these are more often for controlling excessive closure rather than gaining speed.
The "fly to the low wing" concept is explained here:
http://www.simhq.com/simhq3/sims/features/bfm_viewing/bfm_viewing.shtml
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Long article, and i already stumbled into two terms i never heard yet:
in-plane
out-of-plane
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No problem!
Was that a statement or a question???
:)
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LOL a question, i sure forgot a little "?" :D
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Hehehe!
Sometimes the word "plane" in these terms causes confusion. The "plane" in question is the "plane of maneuver" that an aircraft flys in, particularly when turning.
If an aircraft did a level 360 degree turn, its flight path would form a circle parallel to the horizon. That circle defines the "plane of maneuver".
If another aircraft is flying behind that aircraft (same altitude), then it would be flying "in-plane". Anytime the second aircraft orients its flight path out of that circle, then it is flying "out-of-plane".
Other terms are used to describe this concept...they include "three dimensional maneuvering", "split-plane maneuvering", and (sometimes) "maneuvering in the vertical".
The basic idea behind "out-of-plane" maneuvering is to gain either closure or additional turning room by flying a flight path that does not coincide with the target (offensive) or attacker (defensive). The positive effect of gravity is a major part of the concept...the significance of Radial G is that it can reduce the actual turn radius (and increase turn rate) while maintaining the same "cockpit G".
By definition, lag pursuit is anytime you fly a flight path that is not aligned with the other aircraft. So anytime you come "out-of-plane, you are in lag. This is an academic definition and should not be confused with the idea that lag is a "following" maneuver.
On the other hand, by definition, lead pursuit is an "in-plane" maneuver.
Almost all BFM maneuvers are out-of-plane maneuvers in one form or another.
The understanding of out-of-plane maneuvering is absolutely essential to good BFM. Without it, a pilot is left with nothing in his bag of tricks other than pure and lead pursuit...and these are often insufficient to manage the wide variety of positional problems that we encounter in A2A situations.
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Thanks again.
Than i think i am almost always forced to use out-of-plane maneuvers, cause my trust FW190 will usually not even come close to be able to perform an in-plane maneuver against all those hords of Spits and NIKIs. :D