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AD 90-10-05 ACTIVE

Tail Rotor Gearbox
Key Information
AD Number 90-10-05 Status Active
Effective Date June 05, 1990 Issue Date Not specified
Docket Number 89-ASW-52 Amendment 39-6596
Product Type ["Aircraft"] Product Subtype ["Rotorcraft"]
CFR Part --- - Part 39 CFR Section N/A
Citation This information is not available.
Applicability
Manufacturer(s) Bell Helicopter Textron, Inc. California Department of Forestry International Helicopters, Inc. Overseas Aircraft Support Inc Richards Heavylift Helo, Inc. Rotorcraft Development Corporation Rotorcraft Development Corporation Rotorcraft Development Corporation Rotorcraft Development Corporation Rotorcraft Development Corporation Rotorcraft Development Corporation Rotorcraft Development Corporation Rotorcraft Development Corporation Rotorcraft Development Corporation Rotorcraft Development Corporation San Joaquin Helicopters Smith Helicopters Southwest Florida Aviation International Tamarack Helicopters, Inc. West Coast Fabrications
Model(s) TH-1L UH-1E UH-1L UH-1F UH-1B TH-1L UH-1E UH-1L UH-1A UH-1B UH-1H TH-1L UH-1B UH-1E UH-1L UH-1B UH-1E UH-1H UH-1F UH-1E
Regulatory Text

90-10-05 CALIFORNIA DEPARTMENT OF FORESTRY; GARLICK HELICOPTERS; HAWKINS AND POWERS AVIATION, INC.; HERCULES; INTERNATIONAL HELICOPTERS, INC.; OFFSHORE CONSTRUCTION; OREGON HELICOPTERS; PILOT PERSONNEL INTERNATIONAL, INC.; SMITH HELICOPTERS; SOUTHERN AERO CORPORATION; SOUTHWEST FLORIDA AVIATION; AND WEST COAST FABRICATIONS (these helicopters were manufactured by Bell Helicopter Textron, Inc under military contract): Amendment 39-6596. Docket No 89-ASW-52.

Applicability: Model UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and TH-1L helicopters, certificated in any category.

Compliance: Required as indicated, unless already accomplished.

To prevent failure of the tail rotor duplex bearing which could result in loss of tail rotor control and subsequent loss of the helicopter, accomplish the following:

(a) Within the next 100 hours' time in service after the effective date of this AD, determine if the tail rotor gearbox duplex bearing sets, P/N 204-040-424-001, havingthe following serial numbers are installed in the tail rotor gearbox output quill, P/N 204-040-012-009:

Serial Numbers

1 thru 182

MB183 thru MB382
MB442
MB486
MB513
MB518
MB519
MB524
MB530
MB531
MB544
MB545
MB548
MB549
MB551
MB553
MB554
MB561
MB659
MB743
MB744
MB760 thru MB769

MB927 thru MB936

If a part with any of the listed serial numbers is installed, replace with a serviceable part before further flight.

(b) In accordance with FAR Sections 21.197 and 21.199, the helicopter may be flown to a base where the requirements of this AD may be accomplished.

(c) An alternate method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be used when approved by the Manager, Rotorcraft Certification Office, ASW-170, Rotorcraft Directorate, FAA, Southwest Region, Fort Worth, Texas.

This amendment (39-6596, AD 90-10-05) becomes effective on June 5, 1990.