On 5 March 2004, a Mexican Air Force C-26 aircraft detected 11 unidentified objects on FLIR.

The Mexican C-26 encounter matters because it is a 2004 military FLIR case with released footage.
Documented
A C-26 detected 11 objects on FLIR
Documented
The Secretary of Defense released the footage
Debated
The identity of the objects
Unverified
Extraterrestrial origin
Sources are kept in separate layers: official and contemporary material is documented; secondary UFO literature is treated as debated, not as primary evidence.
Documented source.
Documented source.