85-21-01: Forward Engine Mount
FAA order 85-21-01 is an airworthiness directive in force since October 21, 1985. The FAA's subject line: Forward Engine Mount. It names Boeing 737: about 2,896 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
- The Boeing Company
- Models
- 737-300 Series
- On this site
- Boeing 737 2,896 registered
Dates and paperwork
- In force since
- October 21, 1985
- 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 (2,759 characters)
85-21-01 BOEING: Amendment 39-5148. Applies to all Model 737-300 series airplanes delivered prior to line position 1147, certificated in any category. Line position 1147 was delivered September 13, 1985. To detect loose cone bolts and interference between the engine and engine support strut at the forward engine mount, accomplish the following within 30 days after the effective date of this AD, unless already accomplished: \n\n\tA.\tVisually inspect for clearances between the engine and engine support strut in the vicinity of the forward engine mount as specified in Boeing Telegraphic Service Letter M- 7272-2396, dated September 12, 1985. \n\n\tB.\tIf the required clearance cannot be confirmed at any location specified in Boeing Telegraphic Service Letter M-7272-2396, dated September 12, 1985, lower the engine in accordance with Boeing Maintenance Manual Section 71-00-02, revised June 25, 1985, sufficiently to accomplish the following: \n\n\t\t1.\tDisassemble as required to inspect theforward cone bolts and forward mount cone bolt receptacles for pitting, galling, or wear and clearances in accordance with Boeing Maintenance Manual Section 71-21-00, revised October 25, 1984. \n\n\t\t2.\tPenetrant-inspect the cone bolt threads as specified in Boeing Telegraphic Service Letter M-7272-2396, dated September 12, 1985. \n\n\t\t3.\tRepair or replace any damaged cone bolts or cone bolt receptacles. \n\n\tC.\tEliminate interference detected in paragraph A., above, in accordance with procedures specified in Boeing Telegraphic Service Letter M-7272-2396, dated September 12, 1985. \n\n\tD.\tFollowing accomplishment of the above, reinstall the engine in accordance with instructions provided in Maintenance Manual Section 71-00-02, revised June 25, 1985, except that the cone bolts must be tightened to 1200-1400 inch-pounds of torque. \n\n\tE.\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD. \n\n\tF.\tAlternate means of compliance which provide an acceptable level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tAll persons affected by this AD who have not already received copies of the service information cited herein may obtain copies upon request from the Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington. \n\n\tThis amendment becomes effective October 21, 1985.
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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 November 6, 2026. Connections as data: /graph/directive/85-21-01.json · aircraft systems.
