Answer: SST

AnswerCrossword Clue
SSTBygone plane
SSTMach-2 flier (abbr.)
SSTBarrier breaker
SSTIt flew at Mach 2
SSTBarrier-breaking jet
SSTFast flyer
SSTFast plane, for short
SSTHeathrow arr.
SSTConcorde, eg.
SSTJFK giant
SSTConcorde, for ex.
SSTBeleaguered plane
SSTErstwhile flier
SSTOld JFK visitor
SSTErstwhile flyer
SSTJFK visitor, once
SSTFormer flyer
SSTBygone flyer
SSTMach 1 breaker
SSTBygone barrier-breaker
SSTOnetime J.F.K. sight
SSTJFK arrival
SSTAtl. crosser
SSTDroop-nosed flier
SSTFast flier
SSTIt will fly again
SSTIt'll get you overseas PDQ
SSTReflying flier
SSTThe Concorde, e.g.
SSTConcorde
SSTDelta-winged craft
SSTJFK sight
SSTPricey plane
SSTGrounded flier
SSTSupersonic carrier
SSTAtl. crosser, once
SSTIt got you overseas PDQ
SSTTu-144, e.g.
SSTRetired flier
SSTRecord label that shares its name with a fast airplane