My lingering sense is that the Frank's low-speed flap use gave it an up on the Spit 8.
- oldman
Hi Oldman
You pretty much nailed it. However, the advantage does swing at different times and is small and not easy to see without detailed analysis. Overall the advantage goes to the Ki84. The Ki84 has the edge in a couple of important ways and depends on factors that haven't been mentioned yet in this discussion. Allow me to explain.
In the Ki84 v Spit8 engagement the early stages of the fight yields a small advantage to the Spit. That is because the Spitfire has a slighter higher instantaneous turn rate at corner. We are talking 33.4dps for the Spit8 and 32.1 for the Ki84. That's only a 1.3dps advantage for the Spit8, but the problem is that both aircraft bleed speed quickly in this high G phase of the fight so the advantage only lasts long enough to result in a very small angular advantage to the Spit, which would be almost unnoticeable to most pilots.
After that, as both aircraft begin to stall fight at their respective sustained turn rates the edge remains with the Spit8 because the best sustained turn rate for the Spit8 is 24.3dps and for the Ki84 23.3dps so the advantage drops to 1dps. However, to achieve that the Ki84 must use flaps and in that situation the Ki84 has a slightly smaller radius which means that it would take at least 3 minutes for the spit to move onto the Ki84s tail but because of the Ki84s smaller radius the Spit can't pull lead for the shot. There is a BFM technique that can create that lead, but it needs to be repeated and takes time and can easily extend the duration of the fight to the point where the Spit loses it's WEP. At that point the advantage swings back to the Ki84.
The Ki84 has shorter WEP time than the spit8, but gets it back much more quickly. Once the Spit8 loses its WEP it is effectively gone for the rest of the fight. Without WEP the Spit's sustained turn rate drops to 22.3dps while the Ki84 still has access to its 23.3dps for a 1dps advantage. During the brief periods when the Ki84 loses WEP it drops back to an almost identical rate to the Spit8, and then oscillates between a 1dps advantage and neutral for the rest of the fight. In effect, if the Ki84 is still in the fight when the Spit8 runs out of WEP, the Spit8 will eventually be out turned. The 1dps is actually worth more to the Ki84 because as mentioned earlier, it has a slightly smaller turn radius and will not have any difficulty getting lead for a shot. But it gets worse! Because this all takes time and the Spit's fuel burns off far more quickly than the Ki84, the Ki84 can hang in the fight longer and has time to utilize its advantage.
So, here are the factors I mentioned earlier. The first factor is that from the perspective of the Spitfire pilot, staying in the fight after losing WEP is bad because not only is he going to be out turned by an aircraft with a smaller radius and no difficulty getting lead for a shot, he may also run out of fuel before the Ki84 has time to bring his guns to bear. The second factor is that given that the Spit8 is entirely defensive and needs to break off the engagement, at this point his escape window has slammed shut, and hard. The Spitfire simply can't can't break off, the Ki84 accelerates better and is faster so any attempt to extend or reset could only depend on a degree of good luck for its success. Such as the proximity of friendlies, ACK or a mistake by the Ki84 pilot.
In summary, the Spit8 has a small advantage while it's WEP holds out, but it is far from decisive. Any real advantage at this point will come from mistakes by the Ki84 pilot if he doesn't know how to use flaps and achieve a maximum sustained turn. Otherwise, once the Spit loses WEP, the advantage swings to the Ki84 and is now a more decisive advantage because the turn rate is combined with the smaller radius and the Ki84 has time on his side. The Spit can't stay in, and can't get out.
In my experience the main reason the Spit wins engagements with the Ki84 is because Ki84 pilots often lack this knowledge and don't fly with the same confidence and aggression as the Spits who just assume (quite wrongly) that they are flying the superior aircraft. In many ways aggressive Spitfire pilots are bluffing, they just don't have the advantage they think they do and if enough Ki84 pilots read this and fly more confidently... Trust me, the tables will turn.
When I fight a Ki84 I'm cautious with my WEP and if I see I'm fighting a Ki84 who knows what he's doing I know I'm in for a long tough fight. I will press for an advantage, but won't persist until it is too late. I look forward to Ki84 v Spit8 fights because they can be great fights and I've been in many that have gone exactly as I have described here because there are some very good Ki84 drivers in the game.
Hope that helps
Badboy