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Proposed Rule

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

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This proposal would require repetitive inspections for corrosion and cracking of the pivot hinge pins of the horizontal stabilizer, certain follow-on inspections, and replacement of the hinge pins with new or serviceable pins if necessary. This action is necessary to prevent failure of the outer and inner hinge pins due to corrosion or cracking, which could allow the pins to migrate out of the joint and result in intermittent movement of the horizontal stabilizer structure and consequent loss of controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by January 22, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-90-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-90-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6440; fax (425) 917-6590.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

  • Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the Alert Service bulletin reference as two separate issues.
  • For each issue, state what specific change to the proposed AD is being requested.
  • Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2003-NM-90-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-90-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports of corrosion in the pivot hinge pins that attach the horizontal stabilizer center section to the Body Station 1156 support bulkhead on certain Boeing Model 737-300, -400, and -500 series airplanes. Corrosion has been found on outer primary pins and inner failsafe pins made from both 4330 steel and 15-5 PH corrosion-resistant steel (CRES). Investigation has revealed the presence of heavy corrosion on areas of the outer pin not protected by chrome plating and of heavy corrosion on all areas of the inner pin. Such corrosion or cracking could lead to pin failure and allow the pins to migrate out of the joint, resulting in intermittent movement of the horizontal stabilizer structure and consequent loss of controllability of the airplane.

Similar Airplanes

The pivot hinge pins of the horizontal stabilizer on certain Boeing Model 737-100, -200, and 200C series airplanes are identical to those on the affected Model 737-300, -400, and -500 series airplanes. Therefore, all of these models may be subject to the same unsafe condition.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 737-55A1077, dated December 6, 2001, which describes procedures for performing repetitive detailed and magnetic particle inspections for corrosion and cracking of the hinge pin joints of the horizontal stabilizer. The alert service bulletin also describes procedures for replacing the hinge pins with new or serviceable pins if necessary. Accomplishment of the actions specified in the alert service bulletin is intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the actions specified in the alert service bulletin described previously, except as discussed below. Start Printed Page 68302

Differences Between the Proposed Rule and the Alert Service Bulletin

Where the Accomplishment Instructions of the alert service bulletin specify a certain area of inspection of the outer pin as area that “includes the tapered shank, the adjacent thread relief radius, and the threaded end, * * *,” this AD specifies the area that “includes the tapered shank, the adjacent thread relief radius, or the threaded end, * * * .” Additionally, where the Accomplishment Instructions of the alert service bulletin specify a certain other area of inspection of the outer pin as area that “ includes the straight shank and the head, * * * ,” this AD specifies the area that “includes the straight shank or the head, * * * ” The manufacturer has advised us that it has notified opertors of its intention to revise the referenced alert service bulletin to reflect these corrections.

Although the alert service bulletin specifies that operators should contact the manufacturer for disposition of certain corrosion conditions, this proposed AD would require operators to repair those conditions per a method approved by the FAA.

Changes to 14 CFR Part 39/Effect on the Proposed AD

On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance (AMOCs). Because we have now included this material in part 39, only the office authorized to approve AMOCs is identified in each individual AD.

Change to Labor Rate Estimate

We have reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.

Cost Impact

There are approximately 3,132 airplanes of the affected design in the worldwide fleet. The FAA estimates that 1,250 airplanes of U.S. registry would be affected by this proposed AD.

We estimate that it would take approximately 1 work hour per airplane to accomplish the detailed inspection specified in paragraph (a) of the proposed AD, and that the average labor rate is $65 per work hour. Since the requirements of paragraph (a) of this proposed AD apply to the total affected fleet, the cost impact of the inspections required by paragraph (a) of this proposed AD on U.S. operators is estimated to be $81,250, or $65 per airplane, per inspection cycle.

It would take approximately 6 work hours per airplane, per inspection, to accomplish the detailed and magnetic particle inspections described in Part 2 of the Accomplishment Instructions of the specified alert service bulletin. We estimate that if all airplanes were required to accomplish those inspections, the estimated cost impact of the affected airplanes would be $487,500 or $390 airplane, per inspection cycle.

It would take approximately 12 work hours per airplane, per inspection, to accomplish the detailed and magnetic particle inspections described in Part 3 of the Accomplishment Instructions of the specified alert service bulletin. We estimate that if all airplanes were required to accomplish those inspections, the estimated cost impact of the affected airplanes would be $975,000, or $780 per airplane, per inspection cycle.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

The Proposed Amendment

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

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

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

Start Authority

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

End Authority
[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Boeing: Docket 2003-NM-90-AD.

Applicability: Model 737-100, -200, -200C, -300, -400, and -500 series airplanes having line numbers 1 through 3132 inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the outer and inner pivot hinge pins due to corrosion or cracking, which could allow the pins to migrate out of the joint and result in intermittent movement of the horizontal stabilizer structure and consequent loss of controllability of the airplane; accomplish the following:

(a) For all airplanes: Within 90 days after the effective date of this AD, perform a detailed inspection of the pivot hinge pin joints for corrosion and, with hand pressure, check for movement of the hinge pins within the joints of the horizontal stabilizer, per Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1077, dated December 6, 2001. Repeat the detailed inspections and check at intervals not to exceed 180 days until the initial inspection specified in paragraph (b), (d), (f), or (h) of this AD, as applicable, is performed.

Note 1:

For the purposes of this AD, a detailed 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.”

Start Printed Page 68303

(1) If no corrosion is found, and if the hinge pins cannot be moved with hand pressure, the hinge pins are serviceable. No further action is required by this paragraph.

(2) If any pin can be moved with hand pressure, before further flight, remove and inspect both pins and perform follow-on corrective actions per Part 3 of the Accomplishment Instructions of the alert service bulletin.

(3) If any corrosion is found, before further flight, remove and perform a detailed inspection of the pin(s) per Figure 2 (inner pin) or Figure 3 (inner and outer pins), as applicable, of the Accomplishment Instructions of the Alert Service Bulletin; and perform follow-on corrective actions, per the Accomplishment Instructions of the alert service bulletin.

(b) For Models 737-100, -200, and 200C series airplanes: Within 3,000 flight hours or 24 months after the effective date of this AD, whichever occurs first, perform a detailed inspection and magnetic particle inspection for corrosion and cracking of the horizontal stabilizer hinge pins, per Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1077, dated December 6, 2001.

(1) If no corrosion or cracking is found, before further flight, reinstall the pin unless the condition of the other pin in that joint requires that both pins be replaced. (See paragraphs (b)(3) and (b)(4) of this AD.)

(2) If an outer pin is cracked in the area that includes the tapered shank, the adjacent thread relief radius, or the threaded end, but the inner pin is damage free, before further flight, replace the outer pin with a new or serviceable pin, per the Accomplishment Instructions of the alert service bulletin.

(3) If an outer pin is cracked in the area that includes the straight shank or the head, before further flight, replace both the inner and outer pins with new or serviceable pins, per the Accomplishment Instructions of the alert service bulletin.

(4) If any cracks are found on an inner pin, before further flight, replace both the inner and outer pins with new or serviceable pins, per the Accomplishment Instructions of the alert service bulletin.

(5) On any pin, if corrosion is found on a threaded area or in the thread relief radius adjacent to the threads, before further flight, replace the pin with a new or serviceable pin, per the Accomplishment Instructions of the alert service bulletin.

(6) If any corrosion is found on an area of the pin that is not threaded or in a thread relief radius adjacent to threads, before further flight, repair per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA.

(c) For Models 737-100, -200, -200C series airplanes: Thereafter, repeat the inspections required by paragraph (b) of this AD at the times specified in paragraph (c)(1) or (c)(2) of this AD, as applicable.

(1) If BMS 3-27 grease (Mastinox 6856K) is used, repeat the inspection at intervals not to exceed 6,000 flight hours or 48 months, whichever occurs first.

(2) If BMS 3-33 grease is used as a substitute for BMS 3-27 grease (Mastinox 6856K), repeat the inspections at intervals not to exceed 3,000 flight hours or 24 months, whichever occurs first.

(d) For Models 737-100, -200, and -200C series airplanes: Within 12,000 flight hours or 96 months after the effective date of this AD, whichever occurs first, perform a detailed inspection and magnetic particle inspection for corrosion and cracking of the horizontal stabilizer hinge pins, per Part 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1077, dated December 6, 2001.

(1) If no corrosion or cracking is found, before further flight, reinstall the pin unless the condition of the other pin in that joint requires that both pins be replaced. (See paragraphs (d)(3) and (d)(4) of this AD.)

(2) If an outer pin is cracked in the area that includes the tapered shank, the adjacent thread relief radius, or the threaded end, but the inner pin is damage free, before further flight, replace the outer pin with a new or serviceable pin, per the Accomplishment Instructions of the alert service bulletin.

(3) If an outer pin is cracked in the area that includes the straight shank and the head, before further flight, replace both the inner and outer pins with new or serviceable pins, per the Accomplishment Instructions of the alert service bulletin.

(4) If any cracks are found on an inner pin, before further flight, replace both the inner and outer pins with new or serviceable pins, per the Accomplishment Instructions of the alert service bulletin.

(5) On any pin, if corrosion is found on a threaded area or in the thread relief radius adjacent to the threads, before further flight, replace the pin with a new or serviceable pin, per the Accomplishment Instructions of the alert service bulletin.

(6) If any corrosion is found on an area of the pin that is not threaded or in a thread relief radius adjacent to threads, before further flight, repair per a method approved by the Manager, Seattle ACO.

(e) For Models 737-100, -200, -200C series airplanes: Thereafter, repeat the inspections required by paragraph (d) of this AD at the times specified in paragraph (e)(1) or (e)(2) of this AD, as applicable.

(1) If BMS 3-27 grease (Mastinox 6856K) is used, thereafter, repeat the inspections at intervals not to exceed 12,000 flight hours or 96 months, whichever occurs first.

(2) If BMS 3-33 grease is used as a substitute for BMS 3-27 grease (Mastinox 6856K), thereafter, repeat the inspections at intervals not to exceed 6,000 flight hours or 48 months, whichever occurs first.

(f) For Model 737-300, -400, and -500 series airplanes: Within 4,000 flight hours or 24 months from the effective date of this AD, whichever occurs first, inspect the horizontal stabilizer hinge pins, per Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1077, dated December 6, 2001.

(1) If no corrosion or cracking is found, before further flight, reinstall the pin unless the condition of the other pin in that joint requires that both pins be replaced. (See paragraphs (f)(3) and (f)(4) of this AD.)

(2) If an outer pin is cracked in the area that includes the tapered shank, the adjacent thread relief radius, or the threaded end, but the inner pin is damage free, before further flight, replace the outer pin with a new or serviceable pin, per the Accomplishment Instructions of the alert service bulletin.

(3) If an outer pin is cracked in the area that includes the straight shank or the head, before further flight, replace both the inner and outer pins with new or serviceable pins, per the Accomplishment Instructions of the alert service bulletin.

(4) If any cracks are found on an inner pin, before further flight, replace both the inner and outer pins with new or serviceable pins, per the Accomplishment Instructions of the alert service bulletin.

(5) On any pin, if corrosion is found on a threaded area or in the thread relief radius adjacent to the threads, before further flight, replace the pin with a new or serviceable pin, per the Accomplishment Instructions of the alert service bulletin.

(6) If any corrosion is found on an area of the pin that is not threaded or in a thread relief radius adjacent to threads, before further flight, repair per a method approved by the Manager, Seattle ACO.

(g) For Model 737-300, -400, and -500 series airplanes: Thereafter, repeat the inspections required by paragraph (f) of this AD at the times specified in paragraph (g)(1) or (g)(2) of this AD, as applicable.

(1) If BMS 3-27 grease (Mastinox 6856K) is used, therafter, repeat the inspections at intervals not to exceed 8,000 flight hours or 48 months, whichever occurs first.

(2) If BMS 3-33 grease is used as a substitute for BMS 3-27 (Mastinox 6856K), repeat the inspections at intervals not to exceed 4,000 flight hours or 24 months, whichever occurs first.

(h) For Model 737-300, -400, and -500 series airplanes: Within 16,000 flight hours or 96 months from the effective date of this AD, whichever occurs first, perform a detailed inspection and magnetic particle inspection for corrosion or cracking of the horizontal stabilizer hinge pins per Part 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1077, dated December 6, 2001.

(1) If no corrosion or cracking is found, before further flight, reinstall the pin unless the condition of the other pin in that joint requires that both pins be replaced. (See paragraphs (h)(3) and (h)(4) of this AD.)

(2) If an outer pin is cracked in the area that includes the tapered shank, the adjacent thread relief radius, or the threaded end, but the inner pin is damage free, before further flight, replace the outer pin with a new or serviceable pin.

(3) If an outer pin is cracked in the area that includes the straight shank or the head, before further flight, replace both the inner and outer pin with new or serviceable pins.

(4) If any cracks are found on an inner pin, before further flight, replace both the inner and outer pin with new or serviceable pins.

(5) On any pin, if corrosion is found on a threaded area or in the thread relief radius adjacent to the threads, before further flight, replace the pin with a new or serviceable pin.

(6) If any corrosion is found on an area of the pin that is not threaded or in a thread relief radius adjacent to threads, before further flight, contact the Manager, Seattle ACO. Start Printed Page 68304

(i) For Model 737-300, -400, and -500 series airplanes: Thereafter, repeat the inspections required by paragraph (h) of this AD at the times specified in paragraph (i)(1) or (i)(2) of this AD, as applicable.

(1) If BMS 3-27 grease (Mastinox 6856K) is used, thereafter, repeat the inspections at intervals not to exceed 16,000 flight hours or 96 months, whichever occurs first.

(2) If BMS 3-33 grease is used as a substitute for BMS 3-27 (Mastinox 6856K), thereafter, repeat the inspections at intervals not to exceed 8,000 flight hours or 48 months, whichever occurs first.

Alternative Methods of Compliance

(j) In accordance with 14 CFR 39.19, the Manager, Seattle ACO, FAA, is authorized to approve alternative methods of compliance for this AD.

Start Signature

Issued in Renton, Washington, on December 1, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 03-30334 Filed 12-5-03; 8:45 am]

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