# AD 88-25-51 R1: Horizontal Stabilizer - Type: Airworthiness directive - Status: Current - Products: Boeing DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87) and MD-88 - Effective: February 15, 1989 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-6128 - Registered aircraft: 100 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/A6A59E97DC9BB1BD862569F2006E1D57.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/88-25-51-R1 ## The airworthiness directive 88-25-51 R1 McDONNELL DOUGLAS: Amendment 39-6128. Final copy of, and revision to, telegraphic AD T88-25-51 which was issued December 16, 1988. Applicability: McDonnell Douglas Model DC-9-81, -82, -83, -87, and MD-88 series airplanes, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To ensure that the airplane horizontal stabilizer is configured correctly for takeoff, accomplish the following: A. Within 5 calendar days after the effective date of this AD and daily thereafter, perform a functional test of the horizontal stabilizer takeoff position indicator assembly by selecting a center of gravity setting of 13 and a flap setting of 8, and verifying that the longitudinal trim is correctly displayed as 6 plus or minus 1/2 degrees. If the longitudinal trim displayed is not correct, check the adhesive bond strength of the center of gravity and flap indicator dials as indicated in paragraph B., below. 1. If both indicator dials are firmly bonded to their respective wheels, re-rig the horizontal stabilizer takeoff position indicator assembly in accordance with McDonnell Douglas MD-80 Maintenance Manual, Chapter 27-40-12, step 3, paragraph A, "Test Module." 2. If either the flap or center of gravity indicator dials show signs of loose bonding, or if the assembly cannot be re-rigged to bring it within tolerance, replace the horizontal stabilizer takeoff position indicator assembly prior to further flight. B. Within 25 calendar days after the effective date of this AD and thereafter at intervals not to exceed 25 days, accomplish both of the following: 1. Check the center of gravity and flap indicator dial adhesive bond strength in accordance with the "Accomplishment Instructions," with the exception of paragraphs F and J, of McDonnell Douglas Service Bulletin A27-304, Revision 1, dated December 23, 1988. If the indicator dials are dislodged or loosened, replace the horizontalstabilizer takeoff position indicator assembly prior to further flight. 2. Perform an adjustment/test of the horizontal stabilizer takeoff position indicator assembly in accordance with McDonnell Douglas MD-80 Maintenance Manual, Chapter 27-40-12, step 3, paragraph A, "Test Module." If the adjustment/test is not successful, check the adhesive bond strength of the center of gravity and flap indicator dials as indicated in paragraph B.1., above. a. If both indicator dials are firmly bonded to their respective wheels, re-rig the horizontal stabilizer position indicator assembly in accordance with McDonnell Douglas MD-80 Maintenance Manual, Chapter 27-40-12, step 3, paragraph A, "Test Module." b. If either the flap or center of gravity indicator dials show signs of loose bonding, or if the assembly cannot be re-rigged to bring it within tolerance, replace the horizontal stabilizer takeoff position indicator assembly prior to further flight. C. Modification of theflap and center of gravity dial indicators in the horizontal stabilizer takeoff position indicator assembly, in accordance with "Repair Action II" of McDonnell Douglas Service Rework Drawing SRO9270010, New, dated December 17, 1988, constitutes terminating action for the requirements of this AD. D. 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 inspection requirements of this AD. E. 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, Los Angeles Aircraft Office, FAA, Northwest Mountain Region. NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who may add any comments and then send it to the Manager, Los Angeles Aircraft Certification Office. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer, may obtain copies upon request to McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Director of Publications, CL-100 (54-60). These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California. This AD is the final copy of, and revision to, Telegraphic AD T88-25-51. Portions of this amendment were effective earlier to all recipients of Telegraphic AD T88-25-51, issued December 16, 1988, which was effective immediately upon receipt. This amendment (39-6128, AD 88-25-51 R1) becomes effective February 15, 1989. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A6WE](https://openairdocs.org/tcds/A6WE): The Boeing Company; names 5 of 25 models: MD-88, DC-9-81 (MD-81), DC-9-83 (MD-83), DC-9-87 (MD-87), DC-9-82 (MD-82) ## 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: 100 (100 by airframe model, 0 by engine model) - Makers: Mcdonnell Douglas 99, Douglas 1 Models with the most aircraft: - [Mcdonnell Douglas DC-9-83(MD-83)](https://openairdocs.org/model/mcdonnell-douglas-dc-9-83-md-83): 49 aircraft (airframe model) - [Mcdonnell Douglas DC-9-82(MD-82)](https://openairdocs.org/model/mcdonnell-douglas-dc-9-82-md-82): 22 aircraft (airframe model) - [Mcdonnell Douglas MD-88](https://openairdocs.org/model/mcdonnell-douglas-md-88): 14 aircraft (airframe model) - [Mcdonnell Douglas DC-9-87](https://openairdocs.org/model/mcdonnell-douglas-dc-9-87): 13 aircraft (airframe model) - [Douglas DC-9-83](https://openairdocs.org/model/douglas-dc-9-83): 1 aircraft (airframe model) - [Mcdonnell Douglas DC-9-87 (MD-87)](https://openairdocs.org/model/mcdonnell-douglas-dc-9-87-md-87): 1 aircraft (airframe model) All 7 models: https://openairdocs.org/ad/88-25-51-R1/models.md Every aircraft: https://openairdocs.org/ad/88-25-51-R1/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.