observation aircraft

anti-aircraft artillery observation aircraft

observation point / observation post (OP)

observation aircraft (O; obsn acft)

observation and surveillance aircraft

artillery observation aircraft

training aircraft (tng acft) / trainer aircraft

aircraft accident (flight accident; aircraft mishap)

aircraft armaments / aircraft weapons

aircraft accident / flight accident, aircraft mishap

aircraft mishap / flight accident, aircraft accident

aircraft modernization / aircraft upgrade

aircraft track and balance (adjusting balance of aircraft)

aircraft upgrade / aircraft modernization

aircraft weapons / aircraft armaments

flight accident / aircraft accident, aircraft mishap

low flying aircraft / low-flying aircraft

close observation

command-and-observation post

forward observer (FO), forward observation officer; (artillery) observer / spotter

hostile observation

infrared night vision observation device

observation facilities

observation flight

observation patrol

observation satellite

observation slit

supervise the observation of armistice conditions

type of observation

United Nations India-Pakistan Observation Mission (UNIPOM)

United Nations Iraq-Kuwait Observation Mission (UNIKOM)

United Nations Observation Group in Lebanon (UNOGIL)

United Nations Yemen Observation Mission (UNYOM)