restrictor valve /r.str.kt. vlv/
noun a valve designed to permit limited flow in one direction and full flow in the other direction . The extent to which the oil pressure will fall depends on the size of the restrictor valve.
result /r.zlt/ noun a consequence or outcome . Engine oil and cylinder tem-perature will also increase as a result of higher combustion temperatures. . verb
. to result from to happen as a conse-quence . The structural weakness resulted from a minor collision while taxiing two years previously. . to result in to produce as an effect . Failure to secure seat belts could result in serious injury.
resultant /r.zlt.nt/ adjective that
happens as a result of something . The temperature of the land rises, causing the layer of air in contact with it to warm up and expand with a resultant decrease in density. . noun one vector that is the equivalent of a set of vectors

retain 196
.
When two or more velocities act simultaneously on a body, the aircraft movement is called the resultant veloc-ity due to the two or more component velocities.

retain /r.te.n/ verb to keep or to hold

.
Retentivity is the ability of a material has to retain magnetism. . When fuel-dumping, sufficient fuel must be retained for landing.

retard /r.tɑd/ verb 1. to cause to occur later, or to delay . On most mod-ern engines the spark is retarded to top dead centre, to ensure easier starting and prevent kick-back. 2. to move back-wards . When reducing power, always retard the throttles before reducing RPM (revolutions per minute) with the propeller levers.
retentivity /r.tent.v.ti/ noun the
ability to remain magnetised after the magnetising force has gone . Steel has high retentivity, but soft iron has low retentivity.
retract /r.trkt/ verb to move back, or to raise . Mechanically operated sequence valves ensure that the landing gear does not extend until the doors are open and that the landing gear is retracted before the doors close.
retractable /r.trkt.b(.)l/ adjec-tive possible to pull back or raise . retractable undercarriage an under-carriage which can be raised into the fuselage or wings after use . Early air-craft had non-retractable undercar-riages.
retraction /r.trk..n/ noun the act of pulling back or raising . retraction of the undercarriage the raising of the undercarriage into the fuselage after use
return /r.tn/ noun the act of coming back or going back to a place . We’re waiting for the return of the aircraft. .