Airworthiness directives: Boeing,
[Federal Register: March 20, 2001 (Volume 66, Number 54)]
[Proposed Rules]
[Page 15670-15673]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20mr01-17]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2000-NM-361-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Boeing Model 757 series airplanes. The existing AD requires repetitive freeplay checks of the elevator, and replacement of worn elevator power control actuator (PCA) reaction link rod-end bearings and the PCA rod-end bearing, if necessary. That AD also provides an optional terminating action for the repetitive checks. This action would remove the optional terminating action provided by the existing AD, expand the applicability of the existing AD, and require repetitive freeplay checks of the elevator at a revised repeat interval and repetitive lubrication of bearings of the elevator actuator load loop and hinge line. The actions specified by the proposed AD are intended to prevent unacceptable airframe vibration during flight, which could lead to excessive wear of bearings of the elevator PCA load loop and hinge line and result in reduced controllability of the airplane.
DATES: Comments must be received by May 4, 2001.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-361-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 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. 2000-NM-361-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 for Windows 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.
FOR FURTHER INFORMATION CONTACT: Dennis Stremick, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2776; fax (425) 227-1181.
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 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 filedin 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 2000-NM-361-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. 2000-NM-361-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
Discussion
On January 11, 1989, the FAA issued AD 89-03-05, amendment 39-6120 (54 FR 3430, January 24, 1989), applicable to certain Model 757 series airplanes, to require periodic freeplay checks of the elevator, and replacement of worn elevator power control actuator (PCA) reaction link rod-end bearings and the PCA rod-end bearing, if necessary. That action was prompted by reports of
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excessive wear of elevator PCA rod-end and reaction link rod-end bearings. The requirements of that AD are intended to prevent unacceptable airframe vibration during flight.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, there have been numerous occurrences of airframe vibration attributed to excessive freeplay in the bearing of the elevator PCA load loop. The existing AD contains an optional terminating action that involves replacement of the old-design PCA reaction link rod-end bearings with improved bearings. If this optional terminating action is accomplished, the modified airplane is only subject to freeplay checks per the Boeing Maintenance Manual (BMM). The FAA has determined that the freeplay check in the BMM does not accurately measure freeplay of the elevator.
In addition, since the issuance of the existing AD, corrosion has been detected in the bearings of the elevator PCA load loop and hinge line. This corrosion has been attributed to inappropriate lubrication of the bearings. The interval at which the bearings are lubricated is currently specified by the Boeing Maintenance Planning Document.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Service Bulletin 757- 27A0086, Revision 2, dated July 27, 1989, which describes procedures for repetitive freeplay checks of the elevator. The procedures in this service bulletin are similar to those in Boeing Service Bulletin 757- 27A0086, dated June 9, 1988, which was referenced as the appropriate source of service information for the repetitive freeplay checks required by the existing AD. Revision 2 clarifies that certain corrective actions need be done only if replacement of the bearing of the PCA reaction link rod-end does not correct excessive freeplay in the elevator. Accomplishment of the actions specified in the 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 supersede AD 89-03-05 to continue to require repetitive freeplay checks of the elevator, and replacement of worn elevator power control actuator (PCA) reaction link rod-end bearings and the PCA rod-end bearing, if necessary. The proposed AD would remove the optional terminating action specified in the existing AD, expand the applicability of the existing AD, and require new repetitive freeplay checks of the elevator at a revised repeat interval and repetitive lubrication of bearings in the elevator PCA load loop and hinge line. The repetitive freeplay checks would be required to be done per Boeing Service Bulletin 757-27A0086, Revision 2, except as discussed below in the section called ``Differences Between Proposed Rule and Service Bulletin.'' The repetitive lubrication of the bearings in the elevator PCA load loop and hinge line would be required to be done per the Maintenance Planning Document.
Explanation of Revised Repetitive Interval
For airplanes subject to the existing AD, this proposed AD would revise the repetitive inspection interval from an interval stated in flight hours to an interval stated in calendar time. The FAA finds that this change is appropriate because, as stated previously, the unsafe condition addressed by this AD is related to corrosion, which is a function of time rather than flight hours.
Differences Between Proposed Rule and Service Bulletin
Although Boeing Service Bulletin 757-27A0086, Revision 2, lists an effectivity that includes certain Model 757 series airplanes having line positions 2 through 136, the requirements of this proposed AD would apply to all Boeing Model 757 series airplanes. As stated previously, the FAA has determined that the freeplay check in the BMM is not adequate to prevent excessive freeplay in the bearings of the elevator PCA load loop and hinge line and consequent unacceptable airframe vibration. Therefore, the FAA finds that the freeplay checks of the elevator proposed in this action are necessary for all Boeing Model 757 series airplanes.
Boeing Service Bulletin 757-27A0086, Revision 2, specifies that the freeplay checks of the elevator in that bulletin should be repeated at each ``C'' check until improved PCA reaction link rod-end bearings are installed, and thereafter, the checks should be repeated at each ``2C'' check. The FAA finds that such intervals are inadequate to ensure that excessive freeplay in the bearings of the elevator PCA load loop is detected and corrected in a timely manner. Therefore, the proposed AD would require freeplay checks of the elevator to be done at intervals not to exceed 18 months.
Cost Impact
There are approximately 906 airplanes of the affected design in the worldwide fleet.
The cost impact for the existing AD was calculated based on an estimated average labor cost of $40 per work hour. Since the issuance of that AD, the FAA has revised the figures it has used over the past several years in calculating the economic impact of AD activity. In order to account for various inflationary costs in the airline industry, the FAA has determined that it is necessary to increase the labor rate used in these calculations from $40 per work hour to $60 per work hour. The cost impact information, below, has been revised to reflect this increase in the specified hourly labor rate.
The actions that are currently required by AD 89-03-05 affect approximately 90 airplanes of U.S. registry. Those actions take approximately 30 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $162,000, or $1,800 per airplane, per check cycle.
The FAA estimates that 598 airplanes of U.S. registry would be affected by this new proposed AD. The new actions that are proposed in this AD action would take approximately 28 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the proposed requirements of this AD on U.S. operators is estimated to be $1,004,640, or $1,680 per airplane, per check 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
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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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
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:
PART 39--AIRWORTHINESS DIRECTIVES
-
The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
-
Section 39.13 is amended by removing amendment 39-6120 (54 FR 3430, January 24, 1989), and by adding a new airworthiness directive (AD), to read as follows:
Boeing: Docket 2000-NM-361-AD. Supersedes 89-03-05, amendment 39- 6120.
Applicability: All Model 757 series airplanes, 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 (f)(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 unacceptable airframe vibration during flight, which could lead to excessive wear of elevator bearings and result in reduced controllability of the airplane, accomplish the following:
Restatement of Requirements of AD 89-03-05
Repetitive Elevator Freeplay Checks
(a) For Boeing Model 757 series airplanes listed in Boeing Alert Service Bulletin 757-27A0086, dated June 9, 1988, on which the elevator power control actuator (PCA) rod-end and reaction link rod- end bearings are lubricated at intervals of 1,000 flight hours or less, in accordance with Boeing Service Letter 757-SL-27-26, dated April 1, 1988, and on which paragraph (d) of AD 89-03-05 was not done: Within the next 90 days after March 6, 1989 (the effective date of AD 89-03-05, amendment 39-6120), or prior to the accumulation of 4,000 flight hours total time-in-service, whichever occurs later, and thereafter at intervals not to exceed 4,000 flight hours, perform an elevator freeplay check in accordance with Boeing Alert Service Bulletin 757-27A0086, dated June 9, 1988, or Revision 2, dated July 27, 1989. Doing paragraph (d) of this AD ends the repetitive inspections required by this paragraph.
(b) For Boeing Model 757 series airplanes listed in Boeing Alert Service Bulletin 757-27A0086, dated June 9, 1988, not subject to paragraph (a) of this AD, and on which paragraph (d) of AD 89-03-05 was not done: Within the next 90 days after March 6, 1989, or prior to the accumulation of 3,000 flight hours total time-in-service, whichever occurs later, and thereafter at intervals not to exceed 3,000 flight hours, perform an elevator freeplay check in accordance with Boeing Alert Service Bulletin 757-27A0086, dated June 9, 1988, or Revision 2, dated July 27, 1989. Doing paragraph (d) of this AD ends the repetitive inspections required by this paragraph.
Replacement
(c) If freeplay of the elevator exceeds the limits specified in the service bulletin during any check per this AD: Before further flight, replace elevator PCA reaction link rod-end bearings and PCA rod-end bearings, as necessary, with new, improved bearings, in accordance with Boeing Alert Service Bulletin 757-27A0086, dated June 9, 1988, or Revision 2, dated July 27, 1989. After the effective date of this AD, use only Revision 2 of the service bulletin.
New Requirements of this AD
Repetitive Elevator Freeplay Checks
(d) For all airplanes, do elevator freeplay checks per Boeing Service Bulletin 757-27A0086, Revision 2, dated July 27, 1989. Before further flight after the freeplay checks, lubricate the bearings in the elevator PCA load loop and hinge line. Do these actions per the schedule in Table 1 of this AD:
Table 1--Compliance Schedule
Repeat the check and Inspection per
For airplanes subject to...
Do the initial check and lubrication thereafter paragraph (d) ends the lubrication...
at least every... requirements of...
Paragraph (a) of this AD........... At the earlier of.......... 18 months............. Paragraph (a) of this 4,000 flight hours after
AD. the most recent inspection per paragraph (a) of AD 89- 03-05. OR..................... 18 months after the effective date of this AD. Paragraph (b) of this AD........... At the earlier of.......... 18 months............. Paragraph (b) of this Within 3,000 flight hours
AD. after the most recent inspection per paragraph (b) of AD 89-03-05. OR..................... Within 18 months after the effective date of this AD. Neither paragraph (a) nor (b) of At the later of............ 18 months............. N/A. this AD.
3,000 total flight hours... OR..................... 90 days after the effective date of this AD.
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Replacement
(e) If freeplay of the elevator exceeds the limits specified in the service bulletin during any check per paragraph (d) of this AD: Before further flight, replace elevator PCA reaction link rod-end bearings and PCA rod-end bearings, as necessary, with new, improved bearings, per Boeing Alert Service Bulletin 757-27A0086, Revision 2, dated July 27, 1989.
Alternative Methods of Compliance
(f)(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 89-03-05, amendment 39-6120, are NOT considered to be approved as alternative methods of compliance with this AD.
Note 2: 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
(g) 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.
Issued in Renton, Washington, on March 13, 2001. Vi L. Lipski, Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 01-6789Filed3-19-01; 8:45 am]
BILLING CODE 4910-13-U
