Bell OH-58A Technical Manual page 45

BDAR FIXES SHALL BE USED ONLY IN COMBAT OR FOR TRAINING
(AUTHORIZED TRAINING FIXES ARE LISTED IN APPENDIX E.)
IN EITHER CASE, DAMAGES SHALL BE REPAIRED BY STANDARD
4-1. SCOPE. This chapter contains
information on battle damage assess-
ment and expedient repair procedures
for the OH-58 helicopter airframe.
The procedures are to be used only
during combat operations or during
periods of extreme emergency.
a. Section I contains information
pertaining to the various structural
areas which are suspected of being
damaged, and whether the damage is to a
primary or secondary element. Logic
flow chart tables and damage limit
tables are also part of this section.
b. Section II consists of expedient
structural repairs and procedures on
how to perform these repairs and field
fixes.
4-2. ASSESSMENT PROCEDURES. Refer to
Table 4-1.
4-3. GENERAL. Aircraft structure is
classified as primary and secondary
structure.
a. The primary structure is the basic
structure which holds the aircraft
Any serious damage to any
together.
element of the primary structure will
restrict the combat capability of the
aircraft. The primary structure for
each major airframe subassembly is
shown in Figure 4-11, Sheets 1 thru 5.
b. Secondary structures are mounted
on the primary structure.
of structural damage to secondary struc-
tures will restrict combat capability
from a structural point of view;
CHAPTER 4
AIRFRAME
AT THE DISCRETION OF THE COMMANDER.
PROCEDURES AS SOON AS PRACTICABLE.
Section I. INTRODUCTION
however, secondary structure may be
accomplish or support mission functions.
4-4. STRUCTURAL DAMAGE ASSESSMENT AND
REPAIR.
damage assessment and repair consists of
paragraph 4-5; a detail assessment,
paragraph 4-6; and a repair plan,
paragraph 4-10.
whether or not a detail assessment
damage to primary structural elements,
possibly some clean-up and measurement
of the damage and of the damaged ele-
ments.
various aircraft sections in this
measurement and determination of the
detail assessment.
all the aircraft zones is shown in
4-5.
must understand the function of primary
ment consists of a visual inspection of
No amount
mines if any primary caps, webs, or
required for aerodynamic reasons or to
The battlefield structural
three steps: an initial assessment,
The initial assessment
is a quick visual assessment to decide
should be made. A detail assessment
involves the identification of all
The procedure is described for
chapter. This process requires damage
corresponding damage limits.
plan is based on an analysis of the
Figure 4-1.
INITIAL ASSESSMENT. To perform an
initial assessment, the assessor must be
acquainted with structural damage modes
and the primary structure as shown in
the figures of this chapter. He shall
be capable of differentiating between
primary and secondary structure, and he
structural elements.
primary structure.
panels are damaged or fractured and
decides whether:
TM 55-1520-228-BD
The repair
An overall view of
The initial assess-
The assessor deter-
4-1