# AD 90-03-18: Takeoff Configuration Warning Systems - Type: Airworthiness directive - Status: Current - Products: Boeing 727-100 Series, 727-100C Series, 727-200 Series, 727-200F Series, 727 Series, 727C Series, 737-100 Series, 737-200 Series, 737-200C Series, 737-300 Series, 737-400 Series, 737-500 Series and 3 more - Effective: March 7, 1990 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-6498 - Docket: 88-NM-158-AD - Registered aircraft: 848 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CEFD6DC2BD7EA65E8625695E00720D36.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/90-03-18 ## The airworthiness directive 90-03-18 BOEING: Amendment 39-6498. Docket No. 88-NM-158-AD. Applicability: Model 727 and 737 series airplanes, not equipped with a system incorporating Engine Pressure Ratio (EPR) logic for activation of the takeoff warning system, certificated in any category. Compliance: Required within the next 30 months following the effective date of this AD, unless previously accomplished. To prevent the occurrence of takeoff configuration nuisance warnings when taxi operations are conducted with the flaps intentionally retracted, accomplish the following: A. For Boeing Model 727 series airplanes with Auto-Speedbrakes operative: Modify the logic which enables the Takeoff Configuration Warning Systems (TOCWS) in accordance with Boeing Service Bulletin 727- 31-29, January 26, 1979; 727-31-33, dated November 26, 1980; 727-31-35, dated January 26, 1979; or 727-31- 36, dated January 26, 1979, as appropriate. B. For Boeing Model 727 series airplanes not equipped with Auto-Speedbrakes or with the Auto-Speedbrakes deactivated: 1. Modify the logic which enables the Takeoff Configuration Warning Systems (TOCWS) in accordance with Boeing Service Bulletin 727-31-29, January 26, 1979; 727-31-33, dated November 26, 1980; 727- 31-35, dated January 26, 1979; or 727-31-36, dated January 26, 1979, as appropriate; or 2. Adjust the takeoff warning thrust lever actuated switches to operate at 19.5 degrees from the idle stop for takeoff configuration warning system arming in accordance with Boeing Service Bulletin 727-31-30, dated November 11, 1977. Install a circuit breaker guard (cover) on the TOCWS circuit breaker, and safety wire the guard. Operation of the airplane must be in accordance with the Limitations of the Takeoff Configuration Warning System specified in Appendix 39 or 51 (as appropriate) of the Airplane Flight Manual (AFM). C. For Boeing Model 737 series airplanes: Modify the logic which enables the TOCWS in accordance with Boeing Service Bulletin 737-31-1033, Revision 1, dated January 14, 1983. D. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment and then send it to the Manager, Seattle Aircraft Certification Office. E. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplanes, 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, FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington. This amendment (39-6498, AD 90-03-18) becomes effective on March 7, 1990. ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A16WE](https://openairdocs.org/tcds/A16WE): The Boeing Company; names 9 of 17 models: 737-500 Series, 737-100 Series, 737-200C Series, 737-800 Series, 737-300 Series, 737-200 Series, 737-700 Series, 737-400 Series… - [TCDS A3WE](https://openairdocs.org/tcds/A3WE): The Boeing Company; names 6 of 6 models: 727-100 Series, 727 Series, 727-200 Series, 727-100C Series, 727-200F Series, 727C Series ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 848 (848 by airframe model, 0 by engine model) - Makers: Boeing 848 Models with the most aircraft: - [Boeing 737-823](https://openairdocs.org/model/boeing-737-823): 278 aircraft (airframe model) - [Boeing 737-800](https://openairdocs.org/model/boeing-737-800): 139 aircraft (airframe model) - [Boeing 737-824](https://openairdocs.org/model/boeing-737-824): 135 aircraft (airframe model) - [Boeing 737-832](https://openairdocs.org/model/boeing-737-832): 73 aircraft (airframe model) - [Boeing 737-890](https://openairdocs.org/model/boeing-737-890): 60 aircraft (airframe model) - [Boeing 737-724](https://openairdocs.org/model/boeing-737-724): 36 aircraft (airframe model) - [Boeing 737-790](https://openairdocs.org/model/boeing-737-790): 14 aircraft (airframe model) - [Boeing 737-752](https://openairdocs.org/model/boeing-737-752): 13 aircraft (airframe model) - [Boeing 727-223](https://openairdocs.org/model/boeing-727-223): 9 aircraft (airframe model) - [Boeing 737-400](https://openairdocs.org/model/boeing-737-400): 8 aircraft (airframe model) - [Boeing 737-852](https://openairdocs.org/model/boeing-737-852): 7 aircraft (airframe model) - [Boeing 737-500](https://openairdocs.org/model/boeing-737-500): 6 aircraft (airframe model) - [Boeing 737-436](https://openairdocs.org/model/boeing-737-436): 6 aircraft (airframe model) - [Boeing 737-700](https://openairdocs.org/model/boeing-737-700): 5 aircraft (airframe model) - [Boeing 727-227](https://openairdocs.org/model/boeing-727-227): 4 aircraft (airframe model) - [Boeing 737-300](https://openairdocs.org/model/boeing-737-300): 4 aircraft (airframe model) - [Boeing 737-883](https://openairdocs.org/model/boeing-737-883): 4 aircraft (airframe model) - [Boeing 737-205](https://openairdocs.org/model/boeing-737-205): 3 aircraft (airframe model) - [Boeing 737-490](https://openairdocs.org/model/boeing-737-490): 3 aircraft (airframe model) - [Boeing 737-484](https://openairdocs.org/model/boeing-737-484): 3 aircraft (airframe model) All 53 models: https://openairdocs.org/ad/90-03-18/models.md Every aircraft: https://openairdocs.org/ad/90-03-18/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.