heavier aluminum base assembly to which the outer tube
is crimped. The heavy base end causes the marker to
float in the water with the chimney out of the water and
the base in the water.
Within the base assembly is a Mk 72 Mod 0
seawater-activated battery (two batteries in the Mod 2).
The battery is shielded from water contact by two plugs
fitted into 1/2-inch holes on two opposite sides of the
base assembly. A rigid cover (arming plate), held in
place by a retainer ring, is recessed into the base end.
An arrow in the center of the arming plate indicates its
safe or armed position. The words SAFE and ARMED
are stamped into the base rim. Also, a machined notch
in the rim at the armed position helps during night use.
When the arming plate is in the safe position, it
physically blocks the base plugs internally to prevent
them from being accidentally pushed in. When in the
armed position, the arming plate no longer blocks the
base plugs, allowing them to be pushed in at the
appropriate time. A black rubber G-ring circles the base
assembly approximately 1/4 inch from the crimp, which
holds the outer case.
To activate the seawater battery, the base plugs are
pushed in before the marker is actually launched. The
marker is ignited by an electric squib, and power is
supplied by the seawater-activated battery (two batteries
and two squibs in Mod 2). When the marker enters the
water, seawater enters the battery cavity and serves as
an electrolyte, causing the battery to produce a current
that activates the squib. The squib ignites the starter
mix, which, in turn, ignites the red phosphorous
pyrotechnic composition. Gas buildup forces the valve
assembly from the chimney in the nose, and yellow
flame and white smoke are emitted. Burning time
averages 13.5 to 18.5 minutes. Although this marker is
normally used in seawater, it can be used in inland
bodies of fresh water by using table salt and following
the procedures outlined in Pyrotechnic, Screening,
Marking, and Countermeasure Devices, NAVSEA
REVIEW NUMBER 2 ANSWERS TO QUESTIONS Q1. THROUGH Q11.
The Mk 45 Mod 0 aircraft parachute flare is 36 inches long and approximately
4.9 inches in diameter.
The Mk 364 Mod 0 fuze is used with the Mk 45 Mod 0 flare.
The Mk 45 Mod 0 flare has 15 functional settings, from 1,000 to 14,000 feet in
1,000-foot increments. There is one minimum setting of 500 feet.
A spring-loaded detent holds the dial indicator at a selected setting or at SAFE.
The Mk 45 Mod 0 flare is initiated by exerting a force of 18 to 35 pounds to pull
the internal disconnect completely out of the fuze mechanism.
The LUU-2B/B aircraft parachute flare weighs about 30 pounds.
The components of the LUU-2B/B flare are the mechanical timer assembly, the
out-of-line igniter, the parachute suspension system and the case assembly with
The minimum drop distance setting of the LUU-2B/B flare is 150 feet.
The diameter of the parachute suspension system is 18 feet.
At launch, the timer knob is pulled off of the timer by approximately 30 pounds of
force on the lanyard.
Using the LUU-2B/B flare instead of the Mk 45 Mod 0 flare is more advantageous
because the LUU-2B/B flare candle is not ejected from the case of the LUU-2B/B.