Answer: ramjets

AnswerCrossword Clue
RAMJETSEngines that require assisted takeoffs
RAMJETSPowerful engines
RAMJETSCertain plane engines
RAMJETSAircraft propellers without moving parts
ramjetsjet engine operated by the injection of fuel into a stream of air compressed by the forward speed of the aircraft
ramjetsRAMJET, a type of engine