Debriefing, Flight-Crew - An interview with the aircraft
flight crew concerning the conditions at the time of the
combat encounter and during the returning flight for the
purpose of acquiring information that will aid in the
assessment of damage.
Deferrable Damage - Damage whose repair can be
postponed, allowing the aircraft to execute a one-time
evacuation flight or return to service for a limited
number of flight-hours.
Doubler - Additional layer of sheet or strip to reinforce
Expedient Repair - A repair used under combat
conditions whose objective is speed the return of
damaged aircraft to service (a time-expedient repair)
and/or to salvage an aircraft that would be unrepairable
by peacetime field repair standards (a methods-
expedient repair). Expedient repairs generally ignore
aerodynamic cleanliness, and appearance. They may
restore the structure to less than original strength, may
have a limited service life, and may require special
Failure - The state a damaged element occupies when it
is no longer able to support a minimum required load for
a minimum required period of service and/or cannot
meet the minimum required functional performance.
Failure Criteria - The limits on damage of various types
which, if exceeded, require an element to be classified
Fairings - Secondary structure whose function is to
reduce drag; eg streamlined cover, or junction between
Formers - Light secondary structure added to maintain
or improve external shape.
Fuselage Bay - The structure between vertical framing
members such as frames, formers and bulkheads. A
bay is continuous around the circumference of the
airframe. The frame, former or bulkhead forward of the
bay is considered to belong in that bay.
Gusset - Small flat member used to reinforce joints or
Intercostals - Flat longitudinal structural member
(stringer) joining adjacent frames or ribs, usually to
support access door or equipment.
Joggle - Small vertical offset along edge of sheet or
strip to allow it to overlap adjacent component.
Longerons - A main longitudinal brace or support on an
Lugs - A projection or head on a metal part to serve as a
cap, handle support, or fitting connection.
Mounting Bosses - Locally thickened area to provide
support for shaft bearing, threaded connection, or other
Maintenance Authority - The unit commander or his
maintenance priority for battle-damage repair.
Planform - Geometric shape in plan esp of wings and
- The spatial relationship
between elements in a structure within and among
Repair Deferability Assessment - The process used to
determine if an airframe containing failed structural
members must be repaired or can be safely flown
without repair, either for a one-time evacuation flight of
the aircraft or to return the aircraft to service for a
limited number of flight hours.
Restricted Operation - Limits placed on the use of a
damaged aircraft during an evacuation fight.
Ribs - Primary structural member running across wing,
or other airfoil essentially in chordwise direction.
Section, Structural - The area or length of a structural
member as viewed from an endwise direction.
Section Loss - The fractional cross sectional area of a
structural member removed by ballistic damage.
Shear Load - Load (force) applied in shear (stress in
which parallel planes of loaded material tend to slide
past each other).
Skin Panel - The area of skin bounded by longitudinal
framing members above and below and by vertical
framing members fore and aft.
Spall - A chip or fragment removed from the surface or
edge of the material, usually on the back surface of a
part that has been ballistically penetrated.
Spar - Any principal structural member in airfoil running
from tip to top, or from root to tip.