.
see also: air sovereignty test

Fr: exercice spécial de défense aérienne
special air-report 
Special observations made by aircraft operating on international air routes whenever
(a)
severe turbulence or severe icing is encountered;

(b)
moderate turbulence, hail or cumulonimbus clouds are encountered during transonic or
supersonic flight; or

(c)
other meteorological conditions, for example, the other en route weather phenomena specified

for SIGMET messages, are encountered that, in the opinion of the pilot-in-command, may affect the safety or markedly affect the efficiency of other aircraft operations.
. abbreviation: ARS
Fr: compte rendu en vol spécial
special aviation event
An air show, low-level air race, aerobatic competition, fly-in or balloon festival.
Fr: manifestation aéronautique spéciale
special Category I The implementation of local area differential global positioning system (GPS) to provide early satellite navigation precision approach CAT I capability. Standards in Radio Technical Commission for Aeronautics (RTCA) DO 217 provide for certification of the ground station, data link and airborne receiver as a total system. The total system approval is unique to a given runway.
. abbreviation: SCAT I
Fr: catégorie I spéciale
special emergency U.S.: Expression for: acts of unlawful interference
special-use airspace