EXAMPLE 1The choice of which direction to turn at the merge can be crucial. Here’s an example with an old squaddie of mine.
At about the 30 sec mark, PDM in a P-51 and a Spitfire close for a head-to-head merge.
FRAME 1 shows what happens just a few seconds after the merge.
FRAME 1
Just after the Spitfire and P-51 pass each other they both decide to turn. The Spitfire turns to his left while P-51 turns toward his right. As described above this is the classic opening of a nose-to-nose turn with both aircraft turning into each other.
The merge is the first critical decision point in this engagement in deciding which way to turn. Let's analyze this situation with our knowledge of the determining factors of who wins a nose-to-nose contest.
The Spitfire at this point is travelling at 186mph while P-51 is at 265mph. The Spitfire and the P-51 at these velocities are actually both below but near their respective corner velocities. This means that both aircraft are near the envelope for maximum performance turns for their respective aircraft. Of course the Spitfire has much lower wing-loading compared to the P-51 which means it's max performance turn it has a much higher turn rate and much smaller turn radius compared to the Mustang.
RECALL THAT FOR A NOSE-TO-NOSE TURN THE SMALLER TURN RADIUS DETERMINES THE AIRCRAFT WHO WILL GAIN THE ADVANTAGE.In our situation here at the first critical decision point the Mustang deciding to stay in a nose-to-nose turn has now put themselves in a disadvantage after the merge because in this case the Spitfire has a much smaller turn radius than the P-51.
If you are going to commit to a nose-to-nose turn then you want to be confident that your turn radius will be equal to or smaller than your opponent's. In a P-51 who is an average turner this means you have to really judge your enemy's energy state correctly, especially against planes that are better turners to ascertain if you think you have a turn radius advantage against them or not.
Because of the difficulty of gauging this, when fighting a better turning aircraft it often makes a lot of sense to use a nose-to-tail turn instead. A nose-to-tail turn has the effect of stretching out the time it takes to turn which an energy fighter can take advantage of. We will discuss this in later examples.
FRAME 2
FRAME 2 shows the fight developing 40 seconds into the film. As we can see here the effects of the nose-to-nose turn just after the merge are apparent. The Spitfire has gained an angles and positional advantage on P-51, the direct result of the turn radius advantage the Spitfire has compounded by the P-51 making a lazy nose-to-nose turn.
This is the 2nd critical decision point in this engagement. Though at a disadvantage the P-51 still has choices he can make to equalize or neutralize the Spitfire's angles advantage. One effective way to neutralize the situation would have been to continue the nose-to-nose turn into the Spitfire. The maneuver would need to be a maximum performance turn into the nose of the Spitfire. To accomplish this P-51 could have rolled his wing right some more so that his lift vector was pointed at or just below the nose of the Spitfire followed by a continued hard pull on the stick to turn it hard into the nose of the Spitfire.
In continuing a nose-to-nose turn the P-51 would have been essentially re-merging with the Spitfire, albeit probably slightly in front of the Spitfire. There would have been a slight risk of the Spitfire making a snapshot but at these speeds as well has having a little bit of altitude to jink or roll out of plane it would be difficult for the Spitfire to make that shot count.
In our situation, in Frame 3 instead of continuing a max performance nose-to-nose turn into the Spitfire, the P-51 stopped the turn, barrel rolled into a split-s that put the Mustang square in front of the Spitfire.
FRAME 3
Once this occurs the Spitfire is now in a position for a killing shot and though the fight evolved to P-51 extending, the Spit is close enough to get a lucky shot to take off his tail.
Choosing different directions of turn at critical junctures in this fight would have changed the entire outcome of the engagement. Which way you turn may seem like a simple, trivial choice, but it has dramatic consequences.Link for the film:
[can't load it from where I'm at currently. Will do so when I'm able.]
More examples to follow.
Tango, XO
412th FS Braunco Mustangs
