80-21-12 R1: Engine Oil System
FAA order 80-21-12 R1 is an airworthiness directive in force since April 14, 1983. The FAA's subject line: Engine Oil System. It names Great Lakes 2: about 168 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: engine.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Great Lakes Aircraft Company, LLC (John Duncan)
- Models
- 2T-1A-1, 2T-1A-2
- On this site
- Great Lakes 2 168 registered
Dates and paperwork
- In force since
- April 14, 1983
- Docket
- Unknown
- Status
- Current
- The FAA's document
- Read the order on the FAA's site
The order itself the regulatory text, as published
Show the full text (1,754 characters)
80-21-12 R1 GREAT LAKES AIRCRAFT CORPORATION: Amendment 39-3940 as amended by Amendment 39-4625. Applies to Models 2T-1A-1 and 2T-1A-2 (Serial Numbers 501 through 828) airplanes with Lycoming I0-360 or AEIO-360 engines installed, certificated in any category.
Compliance: Required as indicated, unless already accomplished.
To prevent engine oil inlet temperatures from exceeding acceptable limits within the next 50 hours time- in-service after the effective date of this AD, accomplish either paragraph (a) or (b) below:
(a) Remove Cowl Face P/N 50106-2 and Belly Cowl P/N 50105-2 and modify in accordance with Great Lakes Service Bulletin No. 11, dated September 1, 1980, and incorporate Great Lakes Parts Kit SPK 101. Perform engine run-up and inspect oil system for leaks; or
(b) Fabricate and install a louver plate (P/N 50105-33) and louver backing plate (P/N 50105-32) on the side of the belly cowling in accordance with Great Lakes Drawing Number 50105, Sheet 3 of4, Revision C.
(c) The airplane may be flown in accordance with FAR 21.197 to a location where this AD may be accomplished.
(d) An equivalent method of compliance may be approved by the Manager, Atlanta Aircraft Certification Office, FAA Central Region, 1075 Inner Loop Road, College Park, Georgia 30337.
Drawing 50105, Sheet 3 of 4, Revision C, and Great Lakes Service Bulletin No. 11, dated September 1, 1980, pertinent to this AD, may be obtained from Great Lakes Aircraft Company, Drawer A, Eastman, Georgia 31023; telephone (912) 374-5535.
This Amendment 39-4625 revises Amendment 39-3940 (45 FR 67646), AD 80-21-12 in its entirety.
Amendment 39-3940 became effective October 17, 1980.
This Amendment 39-4625 becomes effective April 14, 1983.
Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 7, 2026. Connections as data: /graph/directive/80-21-12 R1.json · aircraft systems.
