stiff (adj)  MOVE (v)  IF THE FLAP CONTROLS DO NOT MOVE EASILY, EXAMINE THE CONTROL SYSTEM FOR CORRECT ADJUSTMENT.  If flap controls are stiff, check control system.
 still (adv)  STAY (v), CONTINUE (v)  MAKE SURE THE "OVHT" LIGHT STAYS ON.  Ensure OVHT light is still illuminated.
       MAKE SURE THE ROTOR CONTINUES TO TURN.  Make sure the rotor still turns.
 stimulate (v)  INCREASE  INCREASE THE AIRFLOW.  Stimulate the airflow.
 stir (v)  MIX  MIX THE BONDING MATERIAL WITH A SPATULA.  Stir bonding material with a spatula.
 STOP (v),
 STOPS, STOPPED, STOPPED  To make an end to a movement or operation  STOP THE ENGINE.  
 store (v)  KEEP, STORAGE (TN)  KEEP THE CARTRIDGES IN A SAFETY AREA.  Cartridges should be stored in a safety area.
      WHEN YOU PUT THE UNIT INTO STORAGE, OBEY THE INSTRUCTIONS SHOWN ON IT.  When you store the unit, follow the instructions shown on it.
 stow (v)  PUT  PUT THE COVERS IN THE IN-FLIGHT STOWAGE.  Stow covers in normal in-flight stowage.
 STRAIGHT (adj) (STRAIGHTER, STRAIGHTEST)  Without curves or bends  MAKE SURE THAT THE STRAIGHT PART OF THE RIGGING PIN IS SMOOTH.  
 straighten (v)  STRAIGHT (adj)  DO NOT TRY TO MAKE THE BENDS IN THE CABLE STRAIGHT.  Do not attempt to straighten bends in the cable.

 
 
 strain (v)  FILTER (TN), STRAIN (TN)  YOU MUST PUT THE OIL THROUGH A FILTER BEFORE YOU USE IT.  Oil must be strained before use.
       DO NOT PUT A STRAIN ON THE BELLOWS.  Do not strain bellows.
 strap (v)  STRAP (TN)  USE A STRAP TO ATTACH THE CABLES TO THE STRUCTURE.  Strap the cables to the structure.
 stress (v)  FORCE (TN)  DO NOT PUT TOO MUCH FORCE ON THE DUCTING.  Do not stress the ducting unnecessarily.
 strike (v)  HIT  MAKE SURE THE SLING DOES NOT HIT THE FUSELAGE SKIN.  Make certain that the sling does not strike the fuselage skin.
 STRIP (n)  A piece of material that is long and thin, but not wide  PUT A STRIP OF ADHESIVE TAPE ALONG THE INSULATION BLANKET.  
 strip (v)  REMOVE  REMOVE THE INSULATION FROM THE WIRE.  Strip the insulation from the wire.
STRIPE (n)  A line (TN) on a surface which is a different color (TN)  THE FLAG HAS RED AND WHITE STRIPES.  
 striped (adj)  STRIPE (n)  THE FLAG HAS RED AND WHITE STRIPES.  The flag is striped red and white.
 stroke (n)  TRAVEL  TO BLEED THE BRAKING SYSTEM, OPERATE THE HAND PUMP HANDLE THROUGH ITS FULL TRAVEL.  Bleed braking system by applying full strokes to hand pump handle.