2. Task/Inspection Suspense Date. At next phase inspection (250 hours).
3. Reporting Compliance Suspense Date. Not applicable.
4. Summary of Problem.
a. Issues with the integrity of the blue and yellow wire harnesses on the -701 engine has prompted a requirement to
check their insulation resistance levels.
c. The purpose of this TB is to measure the insulation resistance levels on the blue and yellow wire harnesses and
compare them with accepted values.
5. End Items to be Inspected. All AH-64A aircraft with T700-GE-701 engines.
6. Assembly Components to be Inspected.
7. Parts to be Inspected.
8. Inspection Procedures.
a. General Theory of Operation.
(1) When the harness under test is connected to the test box (refer to para 11 .a.), all wires and the shield are
tied together to the megohmmeter negative side. The switches numbered 1 through 31 (right side of panel) are
connected to each respective wire in the yellow harness. Switches 1 through 12 (left side of panel) are connected to the
blue harness connector.
(2) Operation of any switch removes that individual wire from all the others including the shield and connects it
to the megohmmeter positive side. The megohmmeter will then read the insulation resistance between the wire under
test and all the others including the shield.
(3) The test box has capability to plug in a megohmmeter capable of generating up to a 500 volt signal (DC
voltage), which is induced into the harness being tested. The test box has the capability of isolating different pins in the
harness, and will provide impedance values while under load.
This test box is for testing the following cables/connectors.
(1) Yellow cables with size 18-31 scoop proof connectors with a normal key arrangement such as found on
cables P/N 6044T60P01 and 6044T60P03.