I flew in an old Air America plane once - a Helio Courier if I remember correctly. It had bullet hole patches in the skin. The pilot flew the plane weaving through the mountains in northern Luzon in the P.I. He landed the aircraft running it right up the mountain side on a bumpy grass strip cut into the jungle. The pilot was Martin Burnham - a good brother and a great bush pilot.
I saw Helio Couriers working in Laos, but never flew in one.
Here is the link to my 1970 Vietnam journal:
http://bswett.com/RVN/1970.html