Tridge, thanks for the reply. Sorry for the completely unscientific and useless discription of weirdness. When I transition to plane, the top left and bottom left esc stop spinning. However this behavior has been insconsistent. Sometimes its the top left and the back bottom. Sometimes it's the top left and bottom right. Everytime I transition to plane, I hear the motor RPM slowly decay (which might be normal as plane is more efficient and requires less RPM). But the arbitrary nature of motors stopping is disconcerning. I expect the back two motors to stop but not any other motors.
I tried calibrating the ESCs with q_esc_cal 1 and 2. I never got good tones on power up. So I manually calibrated each ESC and got the expect high and low throttle tones.
It seems like the Tilt bitmask may be wrong. I compared my param values to yours and gregs and the bit mask definitly matches. I triple checked my engine wiring, which all seems to be good.
Engines arbitrarily stopping kind of freak me out.
Not sure what else to check.
As MRC87 said we can't do this without you.