- road user
- road works
- roadbed stabilization
- roadway
- roaring forties
- rocking
- roll angle
- roll channel
- roll frequency
- roll test
- rolling takeoff
- roof stiffener
- roll-over
- rolled section
- roller
- roller failead
- roller pallet
- rolling hitch
- rolling movement
- rolling stock
- rotor mast
- rotor radius
- rotor speed
- rough sea
- rolling
- rolling circle
- rolling pole
- rolling stability
- rolo ship
- roof panel
- roof section
- roof ventilator
- rot
- rotary intersection
- rotary snowplow
- rotating beacon
- rotor disc
- rotor hub
- rotor torque
- rounteing chart
- rubber stop
- rudder quadrant
- rudder trunk
- run in
- run-up
- running chart
- running schedule
- running stability
- runway centerline
- runway designator
- sack trolley
- safe load
- safety headway
- safety rail
- sag
- roundhouse
- rounteing system
- route description
- route occupation
- route protection
- route release
- routing diagram
- row
- RTG train
- rudder post
- run aground
- runner
- running distance
- running gear
- running safety
- running speed
- runway
- runway gradient
- runway threshold
- rudder
- rudder blade
- rudder port
- rudder travel
- run
- running advice
- running order
- runway alignment
- runway strips
- safe headway
- safety bar
- safety distance
- safety inspection
- safety stop
- sagging
- sail away
- sail loft
- sail plan
- sailing directions
- rooftop heliport
- rotor dick
- rotor efficiency
- rotor head
- rotor inflow
- rotor overspeed
- rough landing