I thought this might be the right place to post a link for the 1966-68 US-Ethiopian mapping mission. The son of one of the mission members (a close personal friend) put together an unbelievably detailed account and amazing website of these activities as a tribute to his father. His father was a fighter pilot in WW2 and Korea.
http://www.ethi-usmappingmission.com/4436.html
Thanks for the link.
This is something I had never heard of before.
Wonderful. Tell your friend we are grateful for his father's service.