TB
1-1520-240-20-108
a. Investigations have revealed that the hoist/cargo control panel has chaffed wires and corrosion on
the terminal lugs. These conditions could cause electrical shorting and inadvertent jettison of external cargo.
b.
For manpower/downtime and funding impacts, see paragraph 12.
c. The purpose of this TB is to perform a one time inspection of the hoist/cargo control panel for
corrosion, wire routing, and wire positioning on terminal lugs. In addition, an inspection for water intrusion
will be performed. As a result of this condition, establishment of a 200/300 hour recurring inspection during
phase will be required for corrosion.
5.
End Items to be Inspected. All CH-47D, MH-47D, and MH-47E aircraft.
6.
Assembly Components to be Inspected.
PART NUMBER
NOMENCLATURE
NATIONAL STOCK NUMBER
145E2334-1
Hoist/Cargo Control Panel
7.
Parts to be Inspected. Internal components of the hoist/cargo control panel.
8.
Inspection Procedures.
a. Prepare aircraft for safe ground maintenance. This includes disconnecting the battery and all
electrical power to the aircraft.
b. Remove hoist/cargo hook panel from overhead console in accordance with TM 55-1520-240-23
and TM 1-1520-252-23.
c. Visually inspect for presence of water/moisture, corrosion, wire chafing, wire routing and wire
positioning on terminal lugs (i.e. assure that no wires are shorted.) Correct any discrepancies in accordance
with paragraph 9 below.
d. Annotate DA Form 2408-18 that " ecurring phase inspections are required at 200 hours for the
R
CH-47D and at 300 hours for the MH-47D and MH-47E aircraft in accordance with paragraphs 8 and 9 of
CH-47-99-ASAM-03, TB 1-1520-240-20-108"
.
e.
Perform a cockpit water intrusion check as follows.
(1) Use a garden hose to allow water to flow over the outside area above the hoist/cargo hook
panel. include sheet metal and windshields.
(2) From inside inspect for and identify all water entry points. For corrective procedures see
paragraph 9 below.
NOTE
The inspection for water entry should be completed as soon as
practical. Local Commanders are authorized to defer this check
as weather conditions dictate but no later than 31 May 1999.
9. Correction Procedures.
a. If corrosion or wire chafing is present, clean corrosion and repair wires in accordance with TM
55-1500-323-24. For all control panels, treat with corrosion prevention compound.
b. For wire routing, assure that wires are tucked between the support posts so that they cannot be
pinched or chafed against the console when the panel is installed.
c. For wire connectors on terminal lugs, bend wire connectors away from the other lugs. Maintain as
much gap as possible between the wire connector and the nearest terminal lug.
d.
For cockpit water/moisture intrusion the following are potential problem areas:
e. For leaks around the cockpit crown window and cockpit lower window panel. Most leaks occur from
improper sealing of the window, or improper installation of attachment screws.
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