Definition of downwash in US English:



  • The downward deflection of an airstream by an aircraft wing or helicopter rotor blade.

    ‘the energy in main-rotor downwash’
    count noun ‘it generates a 200 mph downwash when lifting heavy loads’
    • ‘This account suggests that at low speed and high angle of attack wing downwash could have a blanking effect on airflow to the engine intakes (made worse by any yaw).’
    • ‘The helicopters, which also have been used to deliver humanitarian aid to some inaccessible areas, were chosen partly because of their low rotor downwash.’
    • ‘A group of soldiers in berets and camouflage emerges, crouched low in the fierce downwash from the rotors.’
    • ‘Helicopter downwash ruffled the river's waters as Lynx, Gazelle and Sea Kings hovered over the action.’
    • ‘The downwash from the rotors caused a set of load straps in the cargo bay of the LCM8 to slip, allowing three masonite building sheets to lift in an uncontrolled manner that resulted in a potential FOD hazard.’
    • ‘This made the horizontal tail operate at high negative angles of attack, aggravated by downwash from the slip stream over the inboard sections of the wing flaps.’
    • ‘There is no propeller blade downwash, which reduces the probability of an accidental mine detonation.’
    • ‘In each case, the helicopter descended into rotor downwash and entered what is commonly called the vortex ring state.’
    • ‘Both aircraft are moving at around 50 km/h forward and the downwash of the helicopter is further back.’
    • ‘As the flap is deployed, it causes more lift and more downwash off the trailing edge, thus causing an increase in the nose down pitching rotation.’
    • ‘These lower decks, mainly used by members of ship's company who are not associated with flight operations, contribute plenty of flying debris when they are swept by the downwash of a helicopter rotor.’
    • ‘I dropped 2,500’ in the downwash from the winds and just barely made the start point without smacking into the hill side to get within 400 meters of it.’
    • ‘In such circumstances the helicopter is used to harry and confuse the crew of the boats, flying low over the target and directing the powerful downwash from its rotor blades into the faces of the helmsman.’
    • ‘Even the hangar door needed modifications - a sturdy wooden wind post stiffens it to prevent excessive vibration caused by the massive rotor downwash.’
    • ‘And although the flora is static - you'll see no telltale rustling as tangos creep about or bushes flattened by a chopper's downwash - it certainly beats Rising Sun's plywood cut-outs and tropical wallpaper.’
    • ‘But this action put tension on the parachute lanyard, allowing the rotor downwash to partly inflate the chute.’