TB 1-1520-238-20-119
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 50
flight
hours but NLT 1 October 2001 and report IAW para 14a(2) NLT 5 October 2001.
Reporting Compliance Suspense Date.
Report compliance IAW para 14a(1) NLT 23
August 2001.
4.
Summary of the Problem.
a. AH--64--00--ASAM--08 (TB 1--1520--238--20--100) was issued on 27 Jan 00 to require an initial
and recurring inspection of the fire extingusher tubes for corrosion. Subsequent reports from the field
indicate that, during normal maintenance inspections, extensive corrosion was found inside the engine
fire extinguisher system check valves. The internal check valve ball had corroded to a point that it seized
and was blocking the secondary bottle entry port into the valve.
b. For manpower/downtime and funding impacts, see para 12.
c. The purpose of this TB is to --
(1) Require an initial inspection of the engine number 1 and 2 and the auxiliary power unit
(APU) fire extinguishing check valves, and the fire bottle vertical outlet ports.
(2) Require a recurring inspection at phase numbers 2 and 4 for all three fire extinguisher
system check valves and the 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
Parts To Be Inspected.
Nomenclature
Part Number
NSN
Valve, Stop--Check
7--117210003
4820--01--170--1280
Extinguisher, Fire
30205000--3
4210--01--359--4769
Inspection Procedures.
a. Initial Inspections --
(1) Initial Check Valve Inspection --
(a) Remove the three fire extinguisher system check valves IAW para 12.42, TM
1--1520--238--23 for the AH--64A, and the IETM for the AH--64D.
(b) Remove tube assemblies part number 7--311620503 and part number 7--311620504 IAW
paragraph 12.38, TM 1--1520--238--23 for the AH--64A, and the IETM for the AH--64D. Refer to figure
668, items 26 and 27, TM 1--1520--238--23P, for the AH64A for the location of these tubes or the IETM
for the AH--64D.
(c) Rapidly move the check valve side to side to ensure unrestricted movement of the check
valve ball.
(d) If ball moves unrestricted in check valve and there is no pitting observed, clean valve IAW
(e) If ball is pitted and/or seized to the valve, replace the valve IAW paragraph 9c.
(f) Inspect the three threaded portions on each valve using a 10X magnifier. Replace all
cracked valves.
(2) Initial Fire Bottle Outlet Port Inspection --
2