# AD 75-09-04 R1: Horizontal Stabilizer Rear Spar Center Section Fitting

- Type: Airworthiness directive
- Status: Current
- Products: Boeing 727-100 Series, 727-100C Series, 727-200 Series, 727-200F Series, 727 Series and 727C Series
- Effective: January 22, 1985
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-2142
- Registered aircraft: 25 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/408779C032F61B2E8625683200588875.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/75-09-04-R1

## The airworthiness directive

75-09-04 R1 BOEING: Amendment 39-2174 as amended by Amendment 39-4926. Applies to Boeing Model 727 series airplanes, certificated in all categories, listed in Boeing Service Bulletin 727-55-62, or later FAA approved revisions (line numbers 1 through 641, inclusive). Compliance required as indicated.

To detect cracks in the horizontal stabilizer rear spar center section fitting, accomplish the following:

A. Within the next 750 flight hours after the effective date of this AD, unless accomplished within the last 2250 flight hours, inspect the horizontal stabilizer rear spar center section fitting in accordance with Paragraph III of Boeing Service Bulletin 727-55-62, or later FAA approved revisions or in a manner approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

1. If no cracks are found in the fitting, repeat the inspections at intervals not to exceed 3000 flight hours, until replaced per Paragraph B.

2. If a crackis found at the upper or lower flanges of the fitting and is within the allowable limits specified in Figure 2 of Boeing Service Bulletin 727-55-62, or later FAA approved revisions, prior to further flight, stop drill the crack per the service bulletin. Inspect the stop drilled areas for crack growth at 1500 flight hour intervals, until repaired or replaced in accordance with Boeing Service Bulletin 727-55-62, or later FAA approved revisions, or in a manner approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

3. If a crack is found in any of the hinge lugs and is within the allowable limits specified in Boeing Service Bulletin 727-55-62, or later FAA approved revisions, before further flight, repair the fitting in accordance with Figure 3 of the service bulletin, or in a manner approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. Inspect the repaired fitting thereafter at intervals not to exceed 1500 flight hours.

4. If a crack at any location is beyond the allowable limits specified in Boeing Service Bulletin 727-55-62, or later FAA approved revisions, before further flight, repair in a manner approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, or replace the fitting with a new improved fitting per Paragraph B.

B. As terminating action for this AD, replace the horizontal stabilizer rear spar center section fitting with a new improved 7075-T73 aluminum allow fitting.

C. Airplanes having cracked horizontal stabilizer rear spar center section fittings which require replacement under this AD may be flown in accordance with FAR 21.197 to a base where the replacement can be accomplished.

D. Upon request of an operator, an FAA Maintenance Inspector, subject to the prior approval of the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, may adjust the inspection intervals in this AD, if the request contains substantiating data to justify the increase for that operator.

The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1).

All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124. The documents may also be examined at FAA Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington.

Amendment 39-2174 became effective April 29, 1975.

This Amendment 39-4926 becomes effective January 22, 1985.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [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: 25 (25 by airframe model, 0 by engine model)
- Makers: Boeing 25

Models with the most aircraft:

- [Boeing 727-223](https://openairdocs.org/model/boeing-727-223): 9 aircraft (airframe model)
- [Boeing 727-227](https://openairdocs.org/model/boeing-727-227): 4 aircraft (airframe model)
- [Boeing 727-225](https://openairdocs.org/model/boeing-727-225): 2 aircraft (airframe model)
- [Boeing 727-200F](https://openairdocs.org/model/boeing-727-200f): 1 aircraft (airframe model)
- [Boeing 727-200](https://openairdocs.org/model/boeing-727-200): 1 aircraft (airframe model)
- [Boeing 727-212](https://openairdocs.org/model/boeing-727-212): 1 aircraft (airframe model)
- [Boeing 727-230](https://openairdocs.org/model/boeing-727-230): 1 aircraft (airframe model)
- [Boeing 727-232](https://openairdocs.org/model/boeing-727-232): 1 aircraft (airframe model)
- [Boeing 727-243](https://openairdocs.org/model/boeing-727-243): 1 aircraft (airframe model)
- [Boeing 727-247](https://openairdocs.org/model/boeing-727-247): 1 aircraft (airframe model)
- [Boeing 727-264](https://openairdocs.org/model/boeing-727-264): 1 aircraft (airframe model)
- [Boeing 727-281](https://openairdocs.org/model/boeing-727-281): 1 aircraft (airframe model)
- [Boeing 727-277](https://openairdocs.org/model/boeing-727-277): 1 aircraft (airframe model)

All 13 models: https://openairdocs.org/ad/75-09-04-R1/models.md
Every aircraft: https://openairdocs.org/ad/75-09-04-R1/aircraft.md

Its text cites no advisory circulars or STCs.

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