Bell OH-58A Technical Manual page 92

TM 55-1520-228-BD
AIRFRAME
(5) There are large holes or
cracks in an area of the door or hatch
exposed to the windstream, and peeling
or tearing of the material in flight is
probable.
(6) Fasteners holding major com-
ponents of the hatch, door, or door jamb
together are sheared, pulled-through, or
missing at three or more adjoining
locations.
(7) More than 20 percent of the
total number of fasteners are similarly
damaged.
k. Evaluation of Damage to Fairings
and Cowlings. Classify a damaged
fairing or cowling as failed if any of
the following conditions exist:
(1) Damage to the fairing and
cowling or its attaching structure pre-
vents it from being adequately secured
to the airframe.
(2) The fairing and cowling shows
signs of severe overstress such as
crushing, buckling, or misalignment.
(3) Tracks, rollers, hinges, or
latches are damaged in danger of
becoming unserviceable in flight.
(4) Fasteners securing the fairing
and cowling are sheared, stripped,
pulled-through, or missing at three or
more adjoining locations.
(5) Twenty percent or more of the
total number of fasteners are similarly
damaged.
(6) There are large cracks or
holes in an area of the fairing and
cowling exposed to the windstream, and
peeling or tearing of the material in
flight is probable.
1. Evaluation of Damage to Firewalls.
Classify a damaged firewall as failed if
any of the following conditions exist:
4-48
(1) The firewall shows sign of
severe overstress such as buckling and
misalignment.
(2) Fasteners securing the fire-
wall to the upper deck structure are
sheared, stripped, pulled-through, or
missing at three or more adjoining loca-
tions.
(3) Twenty percent or more of the
total number of fasteners are similarly
damaged.
(4) Damage to the supporting frame-
work causes the firewalls to be loose
and subject to collapsing in flight.
(5) There are large holes or
cracks in the firewall that would pre-
vent the firewall from containing a
fire.
m. Assessing the Effect of Structural
Damage on Other Aircraft Systems.
(1) The assessment standards pro-
vided basically concern the air-
worthiness and flight capability of the
OH-58 airframe. However, every member
of the airframe has a structural and/or
functional purpose. Even those members
which are unessential to airworthiness
may have an important function related
to the integrity and performance of
other aircraft systems and components.
Some of these effects have been con-
sidered and are reflected in the
assessment standards.
(2) The assessor is responsible
for working with other specialists to
determine if damage to airframe
structures will overstress, damage, or
degrade the performance of other system
components. All of the system hardware
near the damage should be evaluated for
these possible effects. Among the types
of conditions to consider are as follows: