New C-37B Gulfstream 550 aircraft, tail #1942

U.S. Air Force Lt. Gen. Jon Thomas, left, Air Mobility Command deputy commander, and U.S. Air Force Lt. Col. William Pearsall, 99th Airlift Squadron instructor pilot, pose for a photo aboard a new C-37B Gulfstream 550 aircraft, tail #1942, on the flightline at Joint Base Andrews, Maryland Dec. 20, 2019. Tail #1942 will be assigned to the 99th AS, which has been performing special airlift missions unabated since 1988.

 

It's a number, and yes, it's on the tail. But let's call it a serial and use 18-1942.