TM 1-1520-240-BD GLOSSARY SECTION I.  TERMS AND DEFINITIONS This appendix contains terms and definitions used in the task of airframe battle-damage assessment and repair. Airframe Section - A major part of the airframe such as the cockpit, cabin or tailcone. Airframe  Zone   -   An   area   or   section   of   the   airframe defined for the purpose of assessing battle damage. Area Loss - The fractional planform area of a structural member removed by ballistic damage. Assessment Rule - A specific criterion used to assess a particular damage condition. Assessor   -   A   trained   maintenance   technician   whose function it is to assess aircraft battle damage. Axial - Pertaining to the line about which a rotating body turns. Axial Load - Force or stress along the line about which a rotating body turns. Battle  -Damaged  Assessment  -   The   process   used   to determine   if   repair   of   a   battle-damaged   aircraft   or system   can   be   safely   deferred   either   for   a   one-time evacuation flight of the aircraft or to return the aircraft to service  for  a  limited  number  of  flight-hours.    The  three major  tasks  of  battle-damage  assessment  are  damage inspection,  damage  evaluation,  and  repair  deferability assessment. Bay   Group   -   Two   or   more   adjacent   bays   in   either direction. Cap  -  Flat  Strip  attached  along  top  or  bottom  edge  of spar, or around rib. Category  I  Structure  -  Primary  framing  members  such as frames, beams, bulkheads and longerons. Category II Structure - Primary skins and stringers. Category III Structure - Fixed secondary structures such as formers, intercostals, and channels. Category IV Structure - Removable secondary structures such as fairings, cowlings, doors and panels. Channels  -  Structural  member  of  channel  form  (eg  top hat, or U). Compression - The act of pressing together. Cowlings - A streamlined housing for aircraft components. Damage, Battle - Damage caused by ballistic projectiles, explosions, and fire. Damage,   Primary   -   Damage   caused   directly   by   the ballistic projectiles, explosions, or fire associated with an attack. Damage,  Secondary  -  Damage  to  structural  members not  directly  exposed  to  the  attack  caused  by  flying  the aircraft with battle-damaged members failed or missing. Damage  Cleanup   -   The   process   of   removing   and/or smoothing damaged material. Damage Diagram - A sketch of a portion of the airframe used to define the location of damaged members. Damage  Evaluation  -  The  process  used  to  determine whether a damaged structure is serviceable or failed. Damage  Inspection  -  The  process  of  inspecting  for  the purpose of locating, identifying, classifying, and recording battle damage. Damage   Labels   -   Marks   and   symbols   placed   on   a structural member to identify areas of damage. Damage  Limit  -  The  amount  of  damage  to  a  member which, if exceeded, requires the member to be classified as failed. Damage Measurement - The process of determining the dimensions of damage to a structure. Damage Mode - A type of damage such as a crack, hole or spall. Damage Monitoring - Periodic inspections of unrepaired damage to check for deterioration and damage growth. Damage Report - A form for recording damage by type, location and nature of damage.  Damage measurements and failure criteria are also recorded. Glossary-1