TB 1-1520-238-20-126
f.
Components/Parts in Work (Depot Level and Others). N/A.
2. Task/Inspection Suspense Date. Complete the inspection IAW paragraph 8 within the next 125 flight
hours, but NLT 2 September 2002.
3.
4.
Summary of the Problem.
a. AH--64--01--ASAM--06 was issued to require an initial and recurring inspection of the fire
extinguisher check valves for corrosion. Subsequent reports from the field indicate that, during normal
maintenance inspections, check valves with the required corrosion prevention compound (CPC), fluid
film, applied are being found gummed up. It has been determined that the required CPC will become
gummy when exposed to high humidity or moisture. If the CPC becomes gummy, the check valve ball
may not completely seal when the fire bottles are used.
b. For manpower/downtime and funding impacts, see paragraph 12.
c.
The purpose of this TB is to --
(1) Supercede the requirements in AH--64--01--ASAM--06 (TB 1--1520--238--20--119).
(2) Perform an initial inspection of the fire extinguisher system check valves and apply CPC,
MIL--C--81309 Type II, to eliminate gumming of the check valves.
(3) Perform a recurring inspection of the check valves and fire bottle outlet ports.
5.
End Items To Be Inspected.
All AH--64 series aircraft.
6.
Assembly Components To Be Inspected.
Nomenclature
Part Number
NSN
Fire Extinguisher System Assy
7--311620010
N/A
7.
Parts To Be Inspected.
Nomenclature
Part Number
NSN
Valve, Stop--Check
7--117210003
4820--01--170--1280
Extinguisher, Fire
30205000--2
4210--01--393--5792
8.
Inspection Procedures.
a. Initial Inspections --
(1) Inspect the check valves within the next 125 flight hours, but NLT 2 September 2002 as
follows --
(a) Remove the three fire extinguisher system check valves IAW paragraph 12.42, TM
1--1520--238--23 for the AH--64A, and the IETM for the AH--64D.
(b) Submerse two way check valve in acetone long enough to remove any old CPC. If
required, use a soft brush to help remove any CPC.
(c) Inspect the check valve ball for pitting, and rapidly move the check valve side to side to
ensure unrestricted movement.
(d) If ball is pitted and/or seized to the valve, install a new valve IAW paragraph 9a.
(e) If ball moves unrestricted and there is no pitting observed, inspect for corrosion. If
corrosion is noted, clean the valve in corrosion removing compound (NSN 6850--00--551--9577) as
follows --
1. Submerse two way check valve in corrosion removing compound (NSN
6850--00--551--9577) for a maximum of 30 minutes. Agitate valve in fluid to remove excess corrosion
and evaporation residue.
2
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