[ARC5] "Retaining" plugs

[Robert Eleazer]

The T-30 throat mike has a very short cord leading to a small two pin connector that is meant to be plugged into an extension of some kind, such as the cord with a PTT switch leading to a PL-68. 

That T-30 connector would not offer much resistance to someone bailing out of an airplane.  Imagine feeling that you were tied to the airplane by your neck.  I lent a T-30 with PTT adapter to a friend of mine to try out in his Cessna.  Actually, it did not work properly, but he said that in any case he could not get out of his head that it would have prevented him from getting out of the airplane in a hurry. 

As Mike says, the fighter pilots had receiving headsets built into their helmet.  I presume they used either throat mikes or mikes built into the oxygen mask.  The early A-8 oxygen mask just fitted over the nose and I guess that throat mikes were used with those.  

Later masks mostly had built in mikes.  PTT was via the airplane.  The P-51 had the PTT switch on the throttle.  The P-38 had it in the center of the wheel like a horn button - and this was unpopular since it required the pilot to take his hands off the controls to talk.  Since the P-38 had separate gun buttons for the cannon and machine guns, with the PTT in the middle of the wheel like a horn button, and with the drop tank jettison button located in some strange place in the cockpit, at least one unit rewired their airplanes.  One gun button fired both the machine guns and cannon (you only very rarely wanted to do otherwise).  The other gun button was rewired for the PTT, and the PTT "horn" button was rewired as the drop tank jettison.  You can imagine what inevitably occurred - try to call the tower and drop your tanks on the ramp.

"Switchology" for aircraft is a remarkably challenging task.  North American Aviation seems to have set the standard in WWII.

Wayne