Snap Roll question - F4U

[Saxman]

Based on a post by Batfink, I think it was, on the Wishlist forum I took my F4U up in the TA to play around with snap-rolls. I found the results a bit interesting and wanted to run some things by y'all:

To the left the snap-roll is EXTREMELY tight and very rapid, and she'll maintain her heading for some time before losing altitude as airspeed is shed. In fact I see what BF was talking about about recover, as she'll continue rolling until stopped with opposite rudder and forward-stick even if the stick and rudder is neutralized.

To the RIGHT, however, is a different story. The roll is more open and somewhat slower, (almost more of a barrel roll) and unless I HOLD full right rudder and back stick she has the tendency to level out and bring HERSELF out of the roll. I'm assuming it has to do with engine torque and the Corsair's favoring turns to the left (torque from the engine naturally makes the F4U want to roll in the OPPOSITE direction of a roll to the right, which negates the snap-roll).

So...

Does this make the Corsair more stable and less prone to spin in turns to the right? Of the two snap-rolls--the faster, tighter one to the left or the more open roll to the right--which would be more advantageous in combat? Does the easier recovery from the snap-roll to the right outweigh the faster rate and smaller radius of the one to the left? When executing maneuvers like the rolling scissors would it be best to risk getting into the snap-roll by going left, or taking advantage of it by going right?

[Golfer]

any time you have the opportunity to do anything "more" than the other guy it's an advantage and you reall should use it.  Whether its in degree per second in roll, level turn or pitch.

If your airplane has any of these advantages over the airplane you're fighting by all means use them.  This means if you roll faster than the other guy, use that to position yourself for a break before the other guy can.  Rolling 270 degrees to break right instead of 90 right will put you that much more ahead of the game.

Little advantages like these can mean the difference between recording a kill and ending up back in the tower with many MA players.

As far as which way to roll...I'd go with the faster.  No point dilly dallying around getting where you want to go.  There really are no advantages to you taking the 'longer way around' as far as turns go.  It's just a matter of practice then learning how to fly the airplane right to the edge of its performance envelope and not departing.

Like anything else with AH...practice, practrice and practice!

[Badboy]

Originally posted by Saxman
When executing maneuvers like the rolling scissors would it be best to risk getting into the snap-roll by going left, or taking advantage of it by going right?

Neither, you don't need to snap roll in a rolling scissors, and you don't get a choice about the direction of roll once the maneuver has begun. In a flat scissors, you should reverse your turn just prior to every merge, but that isn't necessary in a rolling scissors because you should maintain the same helical trajectory throughout the maneuver.  

Also, I don't normally advise snap rolls in a flat scissors, because although you do need to reverse your turn as quickly as you can, you can achieve that by beginning the reversal early. Use rudder to assist the roll by all means, but secret to success in a flat scissors is low speed and a small turn radius, if you have an advantage there you will get the first shot regardless of how quickly you can roll, and if your reversal is much slower than your opponents, as I mentioned before, you can compensate by beginning your reversal early as shown in the diagram below



Here you can see how the Red pilot can execute an early reversal. This is explained more fully in the diagram below, where I also explain what will happen if the pilot with the advantage is unable to make the high aspect shot.



However, in the rolling scissors you should not reverse your turn, but simply maintain the same direction of roll as shown in the diagram below.



Here you can see that while a small turn radius and low speed combined with early reversals are the way to win the flat scissors, the way to win the rolling scissors is to fly a steeper helix angle around the axis of the roll and to maintain a maximum sustained turn rate around the circumference of the scissor's trajectory.

My advice would be to put snap rolls on the back burner, while you focus on the other essential elements of air combat, because I don't think they need to feature heavily in your repertoire.

Hope that helps...

Badboy

PS
I'm working on a training film to explain this based on an AH film supplied by TC, keep an eye open for it, it won't be long now.

[Stoney74]

Excellent graphic Badboy!

[DamnedRen]

A snap role can be very useful. Depending on nose attitude you can cut your speed almost by half, instantly, using a snap roll. The concern might be that you cannot regain the lost energy quickly enough while your opponent is gaining angles on you.

When I teach in the TA I try to ensure a student can enter and exit a snap roll on command to the point it becomes second nature. The ability exit a snap on command will help you anytime you happen to depart controlled flight while dogfighting.

Hope this helps.