I've never found the dive flap to be much use because the line between full control and lawndart is still very thin in the 38L. You might be able to hit a higher speed with them deployed, but you're still far better off powering off and slipping her down the same way you would in a J model. I'm not sure if RL pilots felt that way. I kinda doubt it unless Kelly Johnson was an evil SOB and just put some random gadget on there to make the Army feel better.