87-23-08: Crankshafts
FAA order 87-23-08 is an airworthiness directive in force since November 30, 1987. The FAA's subject line: Crankshafts. It names the Continental IO-520 series, Continental TSIO-520 series engines: about 13,595 aircraft on the U.S. register today across them, 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
- Engine
- Makes
- Teledyne Continental Motors; Teledyne Continental Motors; Teledyne Continental Motors
- Models
- IO-520 Series (all), TSIO-520 Series (all)
- Engine series
- Continental IO-520 series 9,485 aircraft
Continental TSIO-520 series 4,110 aircraft
Dates and paperwork
- In force since
- November 30, 1987
- Docket
- Unknown
- Replaced by
- 97-26-17
- Status
- Historical
- The FAA's document
- Read the order on the FAA's site
The order itself the regulatory text, as published
Show the full text (2,075 characters)
87-23-08 TELEDYNE CONTINENTAL MOTORS (TCM): Amendment 39-5735. Applies to TCM IO-520 and TSIO-520 series engines.
Compliance is required as indicated, unless already accomplished.
To prevent the installation of crankshafts with existing subsurface fatigue cracks which could result in crankshaft failure with resultant loss of engine power, at the next and every subsequent crankshaft removal from the engine case or installation of a replacement crankshaft, accomplish the following:
(a) Prior to installation in the engine, conduct an ultrasonic inspection in accordance with TCM Service Bulletin M87-5, Revision 1, dated May 25, 1987, and Crankshaft Ultrasonic Inspection Procedure, Form X30554, dated February 1981.
(b) If any cracks are found, replace crankshaft with serviceable crankshaft in accordance with TCM Service Bulletin M87-5, Revision 1, dated May 25, 1987.
(c) If no cracks are found, mark the propeller mounting flange in accordance with TCM Service BulletinM87-5, Revision 1, dated May 25, 1987. NOTE: Accomplishment of the ultrasonic inspection does not set aside any requirements for magnaflux or other inspections specified in TCM overhaul manuals.
Upon request, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Atlanta Aircraft Certification Office, Federal Aviation Administration, Central Region, 1669 Phoenix Parkway, Suite 210, Atlanta, Georgia 30349.
TCM Service Bulletin M87-5, Revision 1, dated May 25, 1987, identified and described in this document, is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). Copies may be obtained from Teledyne Continental Motors, P.O. Box 90, Mobile, Alabama 36601. Copies may be examined in the Regional Rules Docket, Office of the Regional Counsel, Room 311, Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803 or at the Office of the Federal Register, 1100 LStreet NW, Room 8401, Washington, DC.
This amendment becomes effective November 30, 1987.
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/87-23-08.json · aircraft systems.