Originally posted by tallyho1
What and how should you use roll in both attacking and defending situation? Also which one changes direction the quickest?
Those are very good questions, and the answers are not clear cut.
The most obvious application of roll rate in both attack and defense is the ability to stay in the plane of motion of the bandit, that is to keep your lift vector parallel with the bandits, in order to take a shot. Of course, that isn’t strictly necessary, but it does make the gunnery problem easier, and most pilots will try to get in plane, by rolling their lift vector until it lines up with the bandits and then pull lead for the shot. The roll rate advantage is important in that respect, because the while the attacker is trying to get his lift vector lined up with the defender, the defender will be trying to avoid that, and the aircraft with the better roll rate should prevail. Here is a diagram so you can see what I mean.
Another way that roll rate can be used to defeat turn rate is anytime you are able to maneuver out of plane with the bandit. The extreme example shown in the next diagram illustrates a situation where one aircraft has pulled into the vertical, while his opponent has stayed in a horizontal turn. The pilot in the vertical can use roll rate to defeat turn rate by rolling so that his lift vector points far enough in front of the bandit so that when he pulls down, he will be on his high six. This works because even aircraft with a relatively low roll rate, still have a roll rate several times higher than any other aircraft’s maximum instantaneous turn rate.
Lastly, no discussion of roll rate would be complete without reference to Colonel Boyd’s OODA loop, because in answer to your question, roll rate can also be used to defeat turn rate when the disparity is significant, (also in real life when the stick forces are significant and pilot fatigue is a factor). The OODA loop was the idea of USAF fighter pilot and highly thought of tactician Colonel John Boyd. His OODA loop stands for Observe, Orient, Decide, and Act... this being the decision process that a pilot goes through in solving any given BFM problem during an engagement. For example, if you see you opponent change his flight path with an aileron roll, you are in the “Observe” phase of the loop. You then need to comprehend what effect your opponents changes will have on the situation, so now you are in the “Orient” phase. Now you need to make a decision from the many options available, and while doing that you are in the “Decide” phase. Finally, you need to execute that decision with a maneuver of your own, so you are in the “Act” phase of the loop, and so it continues.
A pilot who consistently completes the loop faster gains an advantage that increases with each cycle. Because the gains are additive the slower pilot becomes increasingly slower by comparison and therefore less effective until, finally, he is overcome by events.
So how does this theory apply to roll rate and turn rate? For example there is a large variation in roll rate for some WWII aircraft and so those that have higher roll rates allow the pilot to complete the "action" phase more quickly, thereby allowing him to stay inside his opponent’s Boyd loop. This can be very powerful. For example, it is possible to defeat an aircraft with superior level turn performance, from a neutral position and ending with a guns solution, by using just a roll rate advantage. When inexperienced pilots see this, they are amazed that they have an aircraft that can out turn their opponent, yet they can't kill it. The reason is that the pilot of the aircraft with the superior roll rate can use maneuvers that take advantage of the roll rate and increase their advantage incrementally every time they use it. Here is a concrete example.
Suppose we have Aircraft A and Aircraft B and suppose that the Aircraft A can turn at 18dps and has a 2dps turn rate advantage over Aircraft B that turns at 16dps. Normally, 2dps would be considered a decisive advantage in Air Combat, so Pilot A would be expected to win. However, suppose pilot B had a 120dps roll rate and that Pilot A has a 60dps role rate. Now consider what happens in a turn…
A and B are turning hard for 10 seconds say, and so pilot A gains 20 degrees on pilot B and thinks he’s winning the fight. But now B rolls 120 degrees and then continues turning. To follow him pilot A will need to roll for 2 seconds, but pilot B actually completed his 120 degrees roll in one second, so he was able to continue his turn for a full second while pilot A was still completing his roll, at 16dps that means pilot B just gained back 16 of the 20 degrees. Ok, I hear you thinking, Pilot A is still 4 degrees ahead, all he now needs to do is keep turning for the kill. Not so fast… The moment pilot B sees pilot A complete his roll and begin to turn into him again, pilot B repeats his previous 120 degree roll in another direction and now gains another 16 degrees. At the end of that pair of maneuvers, pilot B with the inferior turning aircraft will be 12 degrees farther around than his opponent, and he will gain another 16 degrees every time he does it. Of course, I only picked those numbers because they were easy to work with, they aren’t important, it is the principle that counts. As Boyd said "Time becomes the critical determinant of combat advantage".
After all that, we have still only been discussing the “Act” part of the cycle. When you consider the other parts of the cycle, there are other factors that have an effect on the outcome. For simulation pilots the “Observe” phase is influenced by the viewing system used, the icons, radar, and even the game resolution all provide different visual cues. Their interpretation can lead to different perceptions and estimates of the combat situation. So “Orient” is about understanding what you see, and different levels of comprehension will compel pilots to make different decisions. Inexperienced pilots are more likely to use pure "G for brains", and pull directly into the bandit, while pilots better versed in the subtleties of air combat are likely to have a more complete three dimensional perspective, and thus be able to find more efficient solutions to BFM problems. So the “Orient” phase is about understanding the situation you are in, the implications of the bandits actions, and what you need to do about it, and there may well be several options. That of course leads to the “Decide” phase, and has other influences, for example how many solutions there are, how much fuel or ammo you have remaining, the proximity of other aircraft… and so on. Each phase takes some time and Boyd’s proposition was that the successful pilot will be able to process his OODA loop more rapidly than his opponent. In his own words the successful pilot would "get inside his adversary's loop", thereby forcing the opponent to always react defensively. Boyd once said while describing what it was like to operate inside his opponent’s OODA loop: “It’s like they’re moving in slow motion.” And there are many who can confirm, that is exactly what it is like to fight new pilots online…
Hope that helps...
Badboy
