STRUCTURAL (adj)  Related to the structure  STRUCTURAL REPAIRS ARE SPECIFIED IN THE STRUCTURAL REPAIR MANUAL.  
 STRUCTURALLY (adv)  Related to the structure  THE LIST GIVES YOU STRUCTURALLY IMPORTANT ITEMS.  
 STRUCTURE (n)  1. A "construction"  ATTACH THE WIRES TO THE STRUCTURE.  
    2. The arrangement of something  THE INTRODUCTION GIVES YOU THE STRUCTURE OF THE MAINTENANCE MANUAL.  
 SUBASSEMBLY (n)  An assembly that is a part of a larger assembly  DO NOT CHANGE THE POSITION OF THE SUBASSEMBLIES.  
 subject (v)  APPLY  APPLY SUCTION TO THE SYSTEM.  Subject the system to suction.
 submerge (v)  PUT  PUT THE FILTER ELEMENT INTO THE FLUID.  Submerge filter element in the fluid.
 submit (v)  SEND  SEND THE METAL PARTICLES FOR ANALYSIS.  Submit metal particles for analysis.
SUBSEQUENT
 (adj)  That comes "after"  DO THIS SERVICE BULLETIN ON AIRCRAFT MSN 123 AND SUBSEQUENT AIRCRAFT.  
 SUBSEQUENTLY (adv)  That occurs "after"  SUBSEQUENTLY, THE FUEL LIGHT COMES ON.  
 subsequent to (pre)  AFTER (con)  REMOVE THE HANDLING TOOL AFTER YOU INSTALL THE COMPONENT.  Remove the handling tool subsequent to the installation of the component.
 substance (n)  MATERIAL  THE PRIMER CONTAINS A MATERIAL TO PREVENT CORROSION.  The primer contains a corrosion inhibiting substance.

 
 
 substitute (adj)  EQUIVALENT, ALTERNATIVE  USE AN EQUIVALENT MATERIAL IF MATERIAL XXXX IS NOT AVAILABLE.  A substitute material may be used if material XXXX is not available.
       IF THE SPECIAL TOOLS ARE NOT AVAILABLE, USE AN ALTERNATIVE PROCEDURE.  If special tools are not available, use a substitute method.
 substitute (n)  ALTERNATIVE  YOU CAN USE ALTERNATIVES FOR THESE ITEMS.  Equivalent substitutes may be used instead of these items.
 substitute (v)  REPLACE  DO NOT REPLACE THE SELF-LOCKING NUTS WITH PLAIN NUTS.  Do not substitute plain nuts for self-locking nuts.
 SUBTRACT (v), SUBTRACTS, SUBTRACTED, SUBTRACTED  To "take" from a number or quantity  SUBTRACT COEFFICIENT "A" FROM THE INDICATION.  
 SUCH (adj)  Of the same group  WHEN YOU DO WORK ON SUCH SYSTEMS, USE GOGGLES.  
 suck (v)  SUCTION (TN)  USE SUCTION TO REMOVE THE UNWANTED MATERIAL.  Suck out the debris.
SUDDEN (adj)  That occurs in a short time  SUDDEN MOVEMENT CAN CAUSE DAMAGE TO THE LIMIT STOPS.