retr - roll
- retract arm
- retract position
- retractable
- retractable cross-dam
- retractable foreplanes
- retractable ladder
- retractable slat
- retractable undercarriage
- retractable wheel
- retracted area
- retracted position
- retracting jack
- retraction
- retraction jack
- retraction path
- retraction system
- retreadability
- retreadable
- retreadable tire
- retreating blade
- retreating tip Mach number
- retreating wing
- retrieval
- retrim
- retrimming
- retroactive force
- retrofit aircraft
- retrofit cost
- retrofit kit
- retrofit package
- retrofit schedule
- retrograde integration
- retrorocket
- retrorocket landing impact attenuation
- return difference matrix
- return difference singular value
- return leg
- return passage
- return-to-base mode
- revenue
