Happens to me all the time, I'm probably one of the streakiest players in AH. Some nights everything seems to go my way and I hit all my shots, the plane always seems to have E to spare and I can pull any maneuver I want.
Other nights I miss all my shots, I'm constantly checking the manifold pressure gauge because I could swear that the calibration on my throttle is off and I'm only pulling about 60% of the power I should be, any maneuver seems to bring on the buffet and stall as I wallow through the sky. What's more on those nights apparently my crew chief thought it would be funny to paint a huge bulls eye on my plane, and I swear to myself that it will be the last time I relieve myself in his slit trench rather than wait in line at the latrine.
The biggest thing I try to do is acknowledge that it's a phase and try not to get too mad. I try to make sure I don't play tired, being mentally quick and alert goes along way to playing well I've found. If the rut is deep and lasting I'll try and head to the TA with a squddie/friend and work on my aerial Kung Fu a bit in a 1v1 situation. I also try to step back and approach the game more methodically.