Ed,

 

The "pressure". if any in the boundary layer, will not close the rear of the middle door.  However, the aluminum bracket to which the middle door is mounted can be bent a bit to effect complete closure.

 

Grayhawk

 

Chris, I have original gear with 3 doors.  Haven’t filmed underside of plane in flight, and many thanks for your excellent information.  On the jacks, my middle door hangs slightly open (1/4 inch) at trailing edge, but I always assumed high pressure air will push it closed at cruise.  What do you think?

Re: cg of 360-mine weighs 1125 empty.  It’s almost impossible to load outside the cg.  With me (175 lbs. and light fuel, I need a 20 lb toolbag in the back to keep it in the forward CG.  I have Superior IO360, long cowl and MT 3 blade.

PS  THANK YOU CHRIS ZAVATSON for being a goldmine.  You don’t get this service with Beechcraft of Mooney!