AIRWORTHINESS DIRECTIVE

 

CAA-AD-079/2001

 

Date of issue: August 31, 2001

 

AIRCRAFT - FORWARD FUSELAGE - INSPECTION

 

Applicability: Model 737-600 and -700 series airplanes, line numbers 1 through 908 inclusive; and Model 737-800 series airplanes, line numbers 1 through 455 inclusive; certificated in any category.

 

Effective date: October 04, 2001

 

Compliance: Required as indicated in FAA AD 2001-17-02.

 

Remarks: The compliance of this AD must be recorded in Aircraft Logbook, where applicable the requirements of this AD must be integrated into Aircraft Technical Documentation. Address inquiries concerning this AD to: Civil Aviation Authority, Airworthiness Division, Ruzyne Airport, 160 08 Prague 6, Czech Republic, tel: 420 2 33320922, fax: 420 2 20562270.

 

Ing. Pavel MATOUŠEK

Director of Airworthiness Division

CAA CZ

 

2001-17-02 Boeing: Amendment 39-12393. Docket 2001-NM-236-AD.

Applicability: Model 737-600 and -700 series airplanes, line numbers 1 through 908 inclusive; and Model 737-800 series airplanes, line numbers 1 through 455 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 (e) 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 rapid degradation of the strength of the keel beam splices, which could result in failure of the keel beam and consequent failure of the forward fuselage, accomplish the following:

Repetitive Inspections

(a) Perform a detailed visual inspection for corrosion or cracking of the keel beam splices, according to Boeing Document D626A001 (the ``Maintenance Planning Data Document''), Task Number 53-210-00, dated June 2001. Do the initial inspection at the compliance time specified in paragraph (a)(1) or (a)(2) of this AD; as applicable; and repeat the inspection at least every 18 months, until the requirements of paragraph (c) of this AD have been done.

(1) For airplanes at less than 18 months since date of manufacture as of the effective date of this AD: Inspect within 18 months since date of manufacture, or 90 days after the effective date of this AD, whichever comes later.

(2) For airplanes at 18 months or more since date of manufacture as of the effective date of this AD: Inspect within 24 months since date of manufacture, or 30 days after the effective date of this AD, whichever comes later.

Note 2: For the purposes of this AD, a detailed visual inspection is defined as: ``An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.''

Repair or Replacement

(b) If any corrosion or cracking is found during the inspection required by paragraph (a) of this AD, before further flight, repair or replace the splice plates and bolts with new, improved parts, according to a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD.

Optional Terminating Action

(c) Replacement of splice plates and bolts with new, improved parts not made from 7150-T6511 material; according to a method approved by the Manager, Seattle ACO, or per data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings; constitutes terminating action for the repetitive inspections required by paragraph (a) of this AD.

 

Spares

(d) As of the effective date of this AD, no person shall install a splice plate made from 7150-T6511 material, or with part number 144A7155-1 or 143A7812-1, on any airplane.

Alternative Methods of Compliance

(e) 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 ACO. 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.

Note 3: 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

(f) Special flight permits may be issued in accordance with sections 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.

Effective Date

(g) This amendment becomes effective on September 4, 2001.

Issued in Renton, Washington, on August 13, 2001.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 01-20807 Filed 8-17-01; 8:45 am]

BILLING CODE 4910-01-P