# AD 2008-16-13: Elevator tab control mechanisms

- Type: Airworthiness directive
- Status: Current
- Products: Boeing 737-600 Series, 737-700 Series, 737-700C Series, 737-800 Series, 737-900 Series and 737-900ER Series
- Effective: September 9, 2008
- Published: August 5, 2008, 73 FR 45350–45351
- Issued: July 23, 2008
- Issued as: Final rule
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-15631
- Docket: FAA-2008-0413 (https://www.regulations.gov/docket/FAA-2008-0413)
- Project: 2008-NM-003-AD
- Registered aircraft: 1,128 may be affected, by airframe or engine model (OpenAirDocs)
- Official PDF: https://openairdocs.org/files/sha256/60/14/6014de0d24698bfda4d9974fe38c99ecb493e96f50383394b33a3a1395c64d1b (from https://www.govinfo.gov/content/pkg/FR-2008-08-05/pdf/E8-17748.pdf)
- Federal Register: https://www.federalregister.gov/documents/2008/08/05/E8-17748/airworthiness-directives-boeing-model-737-600--700--700c--800--900-and--900er-series-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9714AB28643A449F8625749C004B8325.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/2008-16-13

## Summary

We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This AD requires replacing the pushrods for the left and right elevator tab control mechanisms with new, improved pushrods. This AD results from a report of a rod end fracture on a rudder power control unit (PCU) control rod, which is similar to the ones used for the elevator tab pushrods. Analysis revealed that the fractured rod end had an incorrect hardness, which had probably occurred during the manufacture of the control rod. We are issuing this AD to prevent fracture of the elevator tab pushrod ends, which could result in excessive in-flight vibrations of the elevator tab, possible loss of the elevator tab, and consequent loss of controllability of the airplane.

## The airworthiness directive

### Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by adding the following new AD:

2008-16-13 Boeing: Amendment 39-15631. Docket No. FAA-2008-0413; Directorate Identifier 2008-NM-003-AD.

### (a) Effective Date

  (a) This airworthiness directive (AD) is effective September 9, 2008.

### (b) Affected ADs

  (b) None.

### (c) Applicability

  (c) This AD applies to Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes, certificated in any category; line numbers 1 through 2196 inclusive.

### (d) Unsafe Condition

  (d) This AD results from a report of a rod end fracture on a rudder power control unit (PCU) control rod, which is similar to the ones used for the elevator tab pushrods. Analysis revealed that the fractured rod end had an incorrect hardness, which had probably occurred during the manufacture of the control rod. We are issuing this AD to prevent fracture of the elevator tab pushrod ends, which could result in excessive in-flight vibrations of the elevator tab, possible loss of the elevator tab, and consequent loss of controllability of the airplane.

### (e) Compliance

  (e) Comply with this AD within the compliance times specified, unless already done.

### (f) Pushrod Replacement

  (f) At the time specified in paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 737-27-1284, dated November 28, 2007; except, where the service bulletin specifies a compliance time after the date on the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD: Replace the pushrods for the left and right elevator tab control mechanisms with new, improved pushrods by doing all the actions in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-27-1284, dated November 28, 2007.

### (g) Parts Installation

  (g) As of the effective date of this AD, no person may install a pushrod assembly, part number 65-45166-24, on any airplane.

### (h) Alternative Methods of Compliance (AMOCs)

  (h)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, ATTN: Tamara Anderson, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6421; fax (425) 917-6590; has the authority to approve AMOCs for this AD, if requested, using the procedures found in 14 CFR 39.19.

  (2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

  (3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane.

### (i) Material Incorporated by Reference

    (i) You must use Boeing Special Attention Service Bulletin 737-27-1284, dated November 28, 2007, to do the actions required by this AD, unless the AD specifies otherwise.

  (1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

  (2) For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

  (3) You may review copies of the service information incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

## Rule preamble

### Dates

This AD is effective September 9, 2008.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of September 9, 2008.

### Addresses

For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

### For further information contact

Tamara Anderson, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6421; fax (425) 917-6590.

### Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. That NPRM was published in the Federal Register on April 24, 2008 (73 FR 22090). That NPRM proposed to require replacing the pushrods for the left and right elevator tab control mechanisms with new, improved pushrods.

### Comments

We gave the public the opportunity to participate in developing this AD. We considered the two comments received. Boeing concurs with the contents of the NPRM, and Continental Airlines has no issues with the NPRM.

### Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD as proposed.

### Costs of Compliance

We estimate that this AD affects 715 airplanes of U.S. registry. We also estimate that it takes about 4 work-hours per product to comply with this AD. The average labor rate is $80 per work-hour. Required parts cost about $8,036 per product. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $5,974,540, or $8,356 per product.

### Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. “Subtitle VII: Aviation Programs,” describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in “Subtitle VII, Part A, Subpart III, Section 44701: General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

### Regulatory Findings

This AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that this AD:

  (1) Is not a “significant regulatory action” under Executive Order 12866,

  (2) Is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), and

  (3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A16WE](https://openairdocs.org/tcds/A16WE): The Boeing Company; names 6 of 17 models: 737-900 Series, 737-700C Series, 737-800 Series, 737-900ER Series, 737-700 Series, 737-600 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: 1,128 (1,128 by airframe model, 0 by engine model)
- Makers: Boeing 1,128

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 737-924ER](https://openairdocs.org/model/boeing-737-924er): 130 aircraft (airframe model)
- [Boeing 737-900ER](https://openairdocs.org/model/boeing-737-900er): 99 aircraft (airframe model)
- [Boeing 737-832](https://openairdocs.org/model/boeing-737-832): 73 aircraft (airframe model)
- [Boeing 737-932ER](https://openairdocs.org/model/boeing-737-932er): 65 aircraft (airframe model)
- [Boeing 737-890](https://openairdocs.org/model/boeing-737-890): 60 aircraft (airframe model)
- [Boeing 737-990ER](https://openairdocs.org/model/boeing-737-990er): 51 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 737-924](https://openairdocs.org/model/boeing-737-924): 12 aircraft (airframe model)
- [Boeing 737-852](https://openairdocs.org/model/boeing-737-852): 7 aircraft (airframe model)
- [Boeing 737-700](https://openairdocs.org/model/boeing-737-700): 5 aircraft (airframe model)
- [Boeing 737-883](https://openairdocs.org/model/boeing-737-883): 4 aircraft (airframe model)
- [Boeing 737-732](https://openairdocs.org/model/boeing-737-732): 3 aircraft (airframe model)
- [Boeing 737-804](https://openairdocs.org/model/boeing-737-804): 1 aircraft (airframe model)
- [Boeing 737-705](https://openairdocs.org/model/boeing-737-705): 1 aircraft (airframe model)
- [Boeing 737-809](https://openairdocs.org/model/boeing-737-809): 1 aircraft (airframe model)

All 22 models: https://openairdocs.org/ad/2008-16-13/models.md
Every aircraft: https://openairdocs.org/ad/2008-16-13/aircraft.md

## Related documents

- [Proposed rule FAA-2008-0413](https://openairdocs.org/proposed/FAA-2008-0413): Notice of proposed rulemaking (NPRM), published Jan 4, 2008
- [Proposed rule FAA-2008-0413](https://openairdocs.org/proposed/FAA-2008-0413): Notice of proposed rulemaking (NPRM), published Apr 24, 2008

Its text cites no advisory circulars or STCs.

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