SB 742-1
M30
c.
All
Visual/Manual
Assembly loose at any joint or not fully
assembled
d. Igniter circuit resistance below 0.675 ohms
All
Test
T-6j
e.
M28A2
Visual/Manual
Ejection pin frozen
M30
f. Igniter wires, electrical connections loose
All
Visual/Manual
g. Fins loose
All
Visual/Manual
h. Rocket not packed with head in direction
All
Visual
indicated on pack
i. Contact ring damaged or improperly assembled
All
Visual
3. Minor:
a. Igniter circuit resistance above 3.025 ohms
All
Test
T-6j
b. Tag missing from shorting clip
All
Visual
c. Fuze safety band missing
M29A2
Visual
d. Ejection pin missing
M29A2
Visual
i. Gaging is not normally required during RI, PI, or UBLI.
Gaging during these inspections should be limited to individual
a. Test with shorting clip in place must not exceed 0.055 rounds having visual evidence of damage or other conditions
ohms. The test will be performed without disturbing the which may preclude loading and firing. Unless such rounds
shorting clip when removed from the container.
requiring gaging are truly representative of the lot being
b. If the ejection pin is missing, the rocket will be consid- inspected, they should be disregarded in evaluating the lot.
ered armed and treated accordingly.
j. Only igniter circuit testers meeting the specifications of
c. Any round with a discernible 360 degree gap between MIL-T-11393 are authorized. Testers supplied under NSN
4925-00-712-0205 meet these requirements.
Authorized
the fuze and the warhead is to be rejected.
testers include, but are not limited to, the Alinco No. 101-5BF,
d. Grasp the fuze with one hand and twist the rocket head 101-5BFG, and the Simpson No. 4-000ITS.
with the other. Repeat holding the fuze with one hand and
twisting the motor body with the other hand. Any movement T-7. Reassessment of rocket motor igniter M20A1.
rejects the rocket.
a. Nonfunctional inspection criteria are given in table T-3.
e. Test will be conducted from the copper contact band The sample size is fifty igniters.
(live lead) or blue auxiliary lead to the unpainted groove in the
support ring (ground contact).
M20A1 Rocket Motor Igniter
f. Test the ejection pin for freedom of movement. This is
Defect
Classification
Accept
Reject
done on the M404A1 fuze (square ejection pin) by merely
Powder leakage
Critical
0
1
depressing the pin with the fingers and releasing it. It is done
Damaged igniter
Major
1
2
on the M404A2 fuze (round ejection pin) by depressing the pin
body
with the fingers and then twisting it and releasing. If the
Damaged lead
Major
1
2
ejection pin binds while being depressed or twisted, reject the
wire
rocket.
Resistance not
Major
1
2
g. When the contact ring is damaged or improperly
within 0.75 to
assembled, so that its functional effectiveness has been
1.25 ohms
destroyed it will be classified as a defect.
b. Functional criteria. Lots passing the nonfunctional test
h. Lots already in an unserviceable condition code for will have 50 samples functionally tested. These samples must
replacement of propellant or igniters or requiring 100 percent be nonfunctionally acceptable. The igniter will be initiated
test of igniter circuit or shorting clip do not require electrical using the firing mechanism from a 3.5-inch rocket launcher. A
test.
failure to ignite is a major defect, accept on one, reject on two.
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