Task/Inspection Suspense Date. Within next 50 flight hours/60 days.
3. Reporting Compliance Suspense Date. No later than 14 Sept 1999 IAW paragraph 14.a. of this mes-
Summary of the Problem.
a. Electrical leads from the center aft fuel cell fuel quantity transmitter have been found chafing against
the fuel quantity transmitter mounting bracket. The wire insulation was completely chafed through and electri-
cal arcing was evident. Chafing in this area is a known problem. Although instructions are provided in the
UH--1 maintenance manual to route wires correctly to preclude chafing, chafing continues to be a problem.
Some aircraft are equipped with an external fuel system (EFS) that
modified the access panel on which the fuel quantity transmitter is
mounted. The EFS was installed on selected National Guard aircraft
via an airworthiness release.
Although chafing has not been reported on aircraft equipped with the EFS, the fuel quantity probe is oriented
similarly and the potential does exist for chafing. In light of this most recent report, a method has been devel-
oped to protect these leads from chafing.
c. The purpose of this TB is to:
(1) Require a one time inspection for chafing fuel quantity transmitter leads.
(2) Require a protective spiral wrap be installed to protect the fuel quantity transmitter leads from
End Items to be inspected. All UH--1H/V series aircraft.
Assembly Components to be Inspected..
NATIONAL STOCK NUMBER
Fuel Quantity Transmitter
Parts to be Inspected. N/A.
Items peculiar to the EFS are not identified in the UH--1 mainte-
nance manual or the Repair Parts and Special Tools List. EFS pecu-
liar items are identified and referenced in "EFS Maintenance In-
struction UH--1 Helicopter" (TM 1--1560--311--23&P). This is a
commercial publication and is not supported by, nor available
through, normal Department of the Army publication distribution.
This manual is provided to each EFS fielding location.
a. Defuel aircraft.
(1) Non--EFS -- IAW chapter 1 of TM 55--1520--210--23--1.