Originally Posted by
nyc6035
If I'm not mistaken one of the 3 prongs is for power - supplied by the plane (whereas a single prong Bose headset you might buy for example has a battery in it). Therefore I 'think' you may not be able to get there from here.
And it looks like that power is 12v, which doesn't appear to be part of the spec of USB type C, but is commonly supported. It's definitely possible, but you'd need to get your own USB C plug with programmable voltage, a voltage regulator to step down from 15 or 20v to 12v, and then a female 2.5mm TS (not barrel) plug, and solder it all together in a way that doesn't look sketchy to foreign airport security. Plus a stereo 3.5mm to 2x 3.5mm mono jack adapter, readily available.