TB 1-1520-210-20-36
g. Components/Parts in Work (Depot and Others). N/A.
2. Task/lnspection Suspense Date. Within the next 30 flight hours or 60 days from receipt of original
message or this TB, whichever is received first.
3. Reporting Compliance Suspense Date. No later than 23 July 97 per paragraph 14.a. of this TB.
4. Summary of Problem.
a. TB 1-1520-210-20-34 (UH-1-97-ASAM-02) directed all units to remove obscuring materials from the
red and green navigation position lights. The original intent of masking these lights was to prevent
disruptive glare during night vision goggle (NVG) operations. However, these masking practices were in
violation of FAA regulations when aircraft were operated in national airspace at night. Once the masking
was removed, an unacceptable level of glare persisted for aircraft operators using NVG. The aeromedical
research laboratory developed a masking scheme in compliance with FAA regulations and NVG user
requirements.
b. For manpower/downtime and funding impacts, see paragraph 12.
c. The purpose of this TB is to:
(1) Require a one-time masking of the red and green position lights to exact dimensions specified.
(2) Ensure that flight operations are conducted in accordance with FAA regulations when flying in
civil airspace at night.
(3) Provide controls to minimize risk during NVG flight operations.
5. End Items to be Inspected. All UH-1H/V aircraft.
6. Assembly Components to be Inspected. Both upper and lower sets of red and green exterior
navigation lights.
N/A.
7. Parts to be lnspected.
8. Inspection Procedures. Ensure actions per paragraph 9. of TB 1-1520-210-20-34 (UH-1-97-ASAM-
02) were performed, which required the removal of all tape and or paint from both upper and lower sets of
red and green lenses. If actions per paragraph 9. of TB 1-1520-210-20-34 (UH-1-97-ASAM-02) were not
performed, complete the procedures of paragraph 9. of TB 1-1520-210-20-34 (UH-1-97-ASAM-02) prior to
implementing paragraph 9. of this TB.
9. Correction Procedures.
a. Lens Modification (Reference Figure 1).
(1) Both upper and lower red and green lenses must be modified. Leave position light dome lens
in assembly.
(2) Determine the horizontal center line of the position lights by drawing or marking from the
center of the Phillips screw and cone point of the light cover and extending across dome lens through the
raised letter or dimple located in the center of the lens.
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