TM 1-1520-240-BD
Figure 1-8. Fragmentation Patterns Associated with a Typical HEI Projectile
b.
Effects. The effect of an HEI impact on metal
airframe structure depends on the fuse mechanism and
the configuration of the structure. For light skin and
stringer construction, the delay-fused projectile normally
produces a relatively clean penetration on the entry
side. In an empty enclosed structure such as a tailcone,
exploding fragments penetrate the opposite skin and
produce massive damage. Total disintegration occurs in
the path of the large, closely-spaced, high-energy
fragments directly ahead of the projectile. Flying
fragments
cause
numerous
penetrations
in
the
surrounding structure. Shock wave and overpressure
effects produce tearing and distortion of the metal.
When the HEI projectile strikes major structures such as
frames and beams, damage may include the loss of
large sections of material and budding and distortion of
the structure. In case where the projectile impacts a thin
light structure such as a tail fin, complete penetration
may occur before the explosion takes place. This will
greatly diminish the damage sustained.
1-13. NBC WARFARE The primary countermeasure to
the NBC threat must be the ability to continue
ACM/BDR while subjected to attack. Flight and ground
support personnel, must be constantly aware of the
effects the NBC weapons can have on their operations.
Personnel
must
be
familiar
with
detection
and
decontamination techniques, protective clothing, and
equipment. The standard decontaminates and decon
procedures currently used with ruin many types of
aviation equipment and materials. However, simple
common sense measures can be used to avoid
becoming contamination. During inspections, battle-
damage repair and cannibalization actions maintenance
personnel must wear NBC protective clothing and must
partially decontaminate work areas and components.
Use of JP-4, hot soapy water, or a decontaminate will
suffice. No guidelines exist on which decontaminants
can be used on specific components.
1-14. THREATS ON THE GROUND . Aircraft on the
ground may be exposed to mortars, bombs, and
artillery. Direct hits or hits near the aircraft will probably
damage the aircraft beyond repair. Damage which can
be repaired may occur when a device explodes some
distance away, and the aircraft is struck by fragments
and blast. Fires may also cause damage.
1-12
