Solved your problem JK methinks, all that air travelling you do, think next time before that shakey hand reaches up to that air injector nozzle above your head on the plane, that twenty plus stoner up front trying to start up is exhausting all those flu ridden fumes into the air con system. It's a well known fact that those air filters are Woolworth ones and are akin to an old smokey diesel breathing in its crankcase compression fumes rendering the air cleaner element US. That coupled together with your monitoring the T's and P's in the wrong location lends itself to all sorts of galloping bronkers ( bronchial defects ) . Observe my monitoring of the T's and P's where I am currently tied up at. Lat 36. 45. 10. N, Long 3. 52. 27 W. Or pack it up and get back down below?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.