00-27791. Airworthiness Directives; Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; correction.

SUMMARY:

This document corrects information in an existing airworthiness directive (AD) that applies to certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. That AD supersedes AD 99-05-15, amendment 39-11063, to require a one-time inspection of the attachment nuts at each end attachment of the elevator tab push rods to measure run-on torque values, and corrective actions, if necessary. That AD also requires replacement of all existing bolts and attachment nuts at the forward and aft end attachment of each elevator tab push rod with new bolts and self-locking castellated nuts with cotter pins. This document corrects an inadvertent error regarding the compliance time for certain requirements of that AD. This correction is necessary to provide an adequate compliance time for the replacement of certain parts.

DATES:

Effective October 25, 2000.

The incorporation by reference of Boeing Service Letter 737-SL-27-118-D, dated December 17, 1999, was approved previously by the Director of the Federal Register as of October 25, 2000 (65 FR 56783, September 20, 2000).

The incorporation by reference of Boeing Alert Service Bulletin 737-27A1205, dated August 28, 1997, was approved previously by the Director of the Federal Register as of March 23, 1999 (64 FR 10935, March 8, 1999).

FOR FURTHER INFORMATION CONTACT:

Scott Fung, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

On September 12, 2000, the Federal Aviation Administration (FAA) issued AD 2000-19-05, amendment 39-11906 (65 FR 56783, September 20, 2000), which applies to certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. That AD supersedes AD 99-05-15, amendment 39-11063, to require a one-time inspection of the attachment nuts at each end attachment of the elevator tab push rods to measure run-on torque values, and corrective actions, if necessary. That AD also requires replacement of all existing bolts and attachment nuts at the forward and aft end attachment of each elevator tab push rod with new bolts and self-locking castellated nuts with cotter pins. That AD was prompted by reports of excessive high-frequency airframe vibration during flight, with consequent structural damage to the elevator tab, elevator, and stabilizer. The actions required by that AD are intended to prevent detachment of an elevator tab push rod due to a detached nut at either end attachment of a push rod, which could result in excessive high-frequency airframe vibration during flight; consequent structural damage to the elevator tab, elevator, and horizontal stabilizer; and reduced controllability of the airplane.

Need for the Correction

Since the issuance of AD 2000-19-05, the FAA has reviewed the wording in paragraph (b) of that AD and finds that there was an inadvertent error in the compliance time. In the preamble of AD 2000-19-05, the FAA concurred with a commenter's request to extend the compliance time in paragraph (b) from, “Within 12 months or 4,000 flight cycles after the effective date of this AD, whichever occurs first: * * *” to “Within 24 months or 4,000 flight cycles after the effective date of this AD, whichever occurs first: * * *” However, in the final rule the FAA inadvertently retained the proposed compliance time of “Within 12 months * * *” This AD corrects the compliance time for paragraph (b) of that AD to read, “Within 24 months or 4,000 flight cycles after the effective date of this AD, whichever occurs first: * * *”

Correction of Publication

This document corrects the error and correctly adds the AD as an amendment to § 39.13 of the Federal Aviation Regulations (14 CFR 39.13).

The AD is reprinted in its entirety for the convenience of affected operators. The effective date of the AD remains October 25, 2000.

Since this action only corrects an error, which extends the compliance time in that AD, it has no adverse economic impact and imposes no additional burden on any person. Therefore, the FAA has determined that notice and public procedures are unnecessary.

List of Subject in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Correction

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39—AIRWORTHINESS DIRECTIVES

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

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Corrected]

2. Section 39.13 is amended by correctly adding the following airworthiness directive (AD):

2000-19-05 Boeing: Amendment 39-11906. Docket 99-NM-69-AD. Supersedes AD 99-05-15, Amendment 39-11063.

Applicability: Model 737-100, -200, -200C, -300, -400, and -500 series airplanes; line numbers 1 through 2939 inclusive; certificated in any category.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c)(1) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent detachment of an elevator tab push rod due to a detached nut at either end attachment of a push rod, which could result in excessive high-frequency airframe vibration during flight; consequent structural damage to the elevator tab, elevator, and horizontal stabilizer; and reduced controllability of the airplane; accomplish the following:

Restatement of Requirements of AD 99-05-15

One-Time Inspection

(a) Within 90 days after March 23, 1999 (the effective date of AD 99-05-15, amendment 39-11063): Perform a one-time inspection of all attachment nuts at each end of each elevator tab push rod to measure the run-on torque values of the nuts, in accordance with Boeing Alert Service Bulletin 737-27A1205, dated August 28, 1997.

Corrective Actions

(1) If the run-on torque value of any end attachment nut is within the limits specified in the alert service bulletin, prior to further flight, ensure that the final seating torque of the attachment nuts is within the torque values specified in the alert service bulletin.

(2) If the run-on torque value of any end attachment nut is outside the limits specified in the alert service bulletin, prior to further flight, replace all existing bolts and attachment nuts at each end of each elevator tab push rod with new bolts and self-locking castellated nuts that have cotter pins installed as a secondary locking feature, in accordance with Boeing Service Letter 737-SL-27-118-D, dated December 17, 1999, and ensure that the final seating torque of the nuts is within the torque values specified in the service letter.

Note 2:

Accomplishment of the inspection and ensuring adequate final seating torque values prior to the effective date of this AD in accordance with Boeing All-Base Telex M-7272-97-0897, dated February 13, 1997, are considered acceptable for compliance with the actions specified in paragraphs (a) and (a)(1) of this AD for only the forward attachment nuts.

New Requirements of This AD

Replacement

(b) Within 24 months or 4,000 flight cycles after the effective date of this AD, whichever occurs first: Replace all existing bolts and attachment nuts at the forward and aft end attachment of each elevator tab push rod with new bolts and self-locking castellated nuts that have cotter pins installed as a secondary locking feature, in accordance with Boeing Service Letter 737-SL-27-118-D, dated December 17, 1999.

Note 3:

Replacements accomplished prior to the effective date of this AD in accordance with Boeing Service Letter 737-SL-27-118-A, dated November 14, 1997; 737-SL-27-118-B, dated April 14, 1999; or 737-SL-27-118-C, dated May 19, 1999; are considered acceptable for compliance with paragraphs (a)(2) and (b) of this AD.

Alternative Methods of Compliance

(c)(1) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

(2) Alternative methods of compliance, approved previously in accordance with AD 99-05-15, amendment 39-11063, are considered to be approved as alternative methods of compliance with paragraph (a) of this AD only.

Note 4:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

Special Flight Permits

(d) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Incorporation by Reference

(e) The actions shall be done in accordance with Boeing Alert Service Bulletin 737-27A1205, dated August 28, 1997, and Boeing Service Letter 737-SL-27-118-D, dated December 17, 1999.

(1) The incorporation by reference of Boeing Service Letter 737-SL-27-118-D, dated December 17, 1999, was approved previously by the Director of the Federal Register as of October 25, 2000 (65 FR 56783, September 20, 2000).

(2) The incorporation by reference of Boeing Alert Service Bulletin 737-27A1205, dated August 28, 1997, was approved previously by the Director of the Federal Register as of March 23, 1999 (64 FR 10935, March 8, 1999).

(3) Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) The effective date of this amendment remains October 25, 2000.

Issued in Renton, Washington, on October 24, 2000.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.