 Five versions of the Sentinel were produced for the U.S. Army Air Force (USAAF); the L-5, L-5B, L-5C, L-5E and L-5G.There was no official L-5A variant as is often reported because the designation was intended for a version of the aircraft that was never built.Nonetheless, many people in and out of the military still refer to the standard "observer" version of the L-5 as an L-5A.