TM 1-1520-240-BD
CAUTION
Use of lead pencil in some areas will
cause corrosion.
1 Use a bright color to outline each
area of damage as it is located and recorded on the DA
Form 2404 (Figure 2-4). Attempt to make the outline
visible from all angles.
2 Draw arrows on inside skin panels,
webs, and bulkheads to point toward areas of damage
that are hidden.
c.
Damage Measurement. If the assessment
indicates that the damage should be repaired by BDAR
or standard procedures, no damage measurement is
necessary. Damage measurement is required to
determine if structural repair (other than cleanup) can be
deferred, or if self-recovery of the damaged aircraft is
feasible. Damage measurement may also be required if
a BDAR repair does not restore original strength. Begin
damage measurement with the largest damage.
(1) Caps and Longerons.
(a) The parameters involved in measuring
damage to a cap or longeron are shown in Figure 2-5.
The pertinent values are as follows:
CD
=
Depth of damage.
CL
=
Length (width) of damage.
A
=
CL X CD = area of damage.
D
=
Distance between damages.
In Figure 2-6, the length of the flattened cross section
shown is a+b.
If CD is the depth of the damage into the flattened cross
section, then CS is the length of the remaining effective
cross section still capable of supporting load, and
CS=(a+b)-CD. Always measure CD.
Figure 2-6. Damaged Cross Section
2-10
