01-29428. Airworthiness Directives; Boeing Model 757-200, -200CB, and -200PF; and 767-200, -300, and -300F Series Airplanes

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 757-200, 200CB, and -200PF; and 767-200, -300, and -300F series airplanes. This proposal would require modification of the right main landing gear and auto-speedbrake control system to provide an air/ground signal to the system. This action is necessary to prevent uncommanded deployment of the auto-speedbrake spoilers during flight, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by January 11, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-75-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 [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-75-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:

Barbara Mudrovich, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

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 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 2001-NM-75-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. 2001-NM-75-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received a report of two incidents of in-flight auto-speedbrake deployment during landing approach on a Boeing Model 767 series airplane. In one incident, the airplane was at approximately 1,500 feet altitude with the landing gear down and the auto-speedbrake spoilers armed. There was a vibration and the spoilers automatically deployed to 20 degrees during flap extension. Investigation revealed that an incorrect air/ground data input from the proximity switch electronics unit (PSEU) can deploy the auto-speedbrake spoilers. The auto-speedbrake system uses only input from the PSEU as its source for air/ground data, but this single source of air/ground data may not be adequate, in that incorrect data could result in uncommanded deployment of the auto-speedbrake spoilers in flight. Uncommanded deployment of the auto-speedbrake spoilers during flight, if not corrected, could result in reduced controllability of the airplane.

Boeing Model 757 series airplanes have a similar auto-speedbrake control system, therefore, those airplanes may also be subject to the same unsafe condition described above.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletins 757-27A0130, dated August 31, 2000, and 767-27A0160, dated December 20, 2000, which describe the following modification procedures:

Work package	Boeing Alert Service Bulletin 757-27A0130
1	Install the truck tilt sensor wire bundle between the main equipment compartment and the right main landing gear (MLG).
2	Install a truck tilt sensor and target on the right MLG. Replace the terminal rail in the forward junction box and the electrical conduits between the box and the truck tilt sensor. Install sensor wires to the truck tilt sensor.
3	Install a wire between the P36 and P37 panel assemblies in the main equipment compartment. The tilt sensor wires are installed in the P36 and P37 panel assemblies, and the tilt sensor relay is installed in the P37 panel assembly. Do the system functional tests. (The service bulletin specifies that each work package can be done independently or at the same time, in any sequence, but the functional tests in Work Package 3 should be done last.)

Work package	Boeing Alert Service Bulletin 767-27A0160
1	Install the truck tilt sensor wiring between the main electronic equipment center disconnect to the right MLG of the forward cargo compartment.
2	Replace the J2 and J4 junction boxes and conduit on the right MLG. Install new truck tilt sensor wiring.
3	Install new truck tilt proximity sensor and target on the right MLG.
4	Install truck tilt sensor wiring to the P33 forward miscellaneous electronic equipment panel of the main electronic equipment center. Do the wiring changes to the P36 left miscellaneous electronic equipment panel. Install a new gear tilt relay in the P33 panel. Do a system checkout test to make sure the truck tilt sensor and auto-speedbrake, engine probe heat, pitot probe heat, auto ice detection, antiskid, tire pressure indication, brake temperature monitoring, and brake cooling fan systems operate properly. (The service bulletin specifies that each work package can be done independently or at the same time, in any sequence, but Work Package 4 should be done last.)

Accomplishment of the actions specified in the service bulletins 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 service bulletins described previously, except as discussed below.

Related Rulemaking

Boeing Alert Service Bulletin 767-27A0160, is cited in this proposed AD as the correct source of service information for doing certain actions. That service bulletin references five other related service bulletins that should be done before, or concurrently, with this proposed AD. Those service bulletins have been addressed in the previously issued ADs listed below:

• On July 28, 1994, the FAA issued AD 94-16-03, amendment 39-8993 (59 FR 41229, August 11, 1994), applicable to certain Boeing Model 767 series airplanes equipped with Pratt & Whitney JT9D-7R4 or General Electric CF6-80A series engines, which requires inspections, adjustments, and functional tests of the thrust reverser system. That AD also requires installation of an additional thrust reverser system locking feature, periodic functional tests of that locking feature following its installation, and repair of any discrepancy found. (The service bulletins cited in that AD are Boeing Service Bulletins 767-78-0061, Revision 1, and 767-78-0060, Revision 2, both dated August 5, 1993.)
• On February 27, 1996, the FAA issued AD 95-13-12 R1, amendment 39-9528 (61 FR 9092, March 7, 1996), applicable to certain Boeing Model 767 series airplanes equipped with General Electric CF6-80C2 series engines, which requires tests, inspections, and adjustments of the thrust reverser system. That AD also requires installation of a terminating modification and repetitive follow-on actions. (The service bulletin cited in that AD is Boeing Service Bulletin 767-78-0063, Revision 1, dated April 29, 1993.
• On June 3, 1994, the FAA issued AD 94-12-10, amendment 39-8938 (59 FR 31508, June 20, 1994), applicable to certain Boeing Model 767 series airplanes equipped with Pratt & Whitney PW4000 series engines, which requires repetitive inspections, tests, adjustments, and functional checks of the thrust reverser system and of selected engine wiring. That AD also requires installation of a terminating modification, repetitive operational checks of that installation, and repair of any discrepancy found. (The service bulletin cited in that AD is Boeing Service Bulletin 767-78-0062, Revision 1, dated December 17, 1992.)
• On August 4, 1994, the FAA issued AD 94-17-03, amendment 39-8998 (59 FR 41647, August 16, 1994), applicable to certain Boeing Model 767 series airplanes equipped with Rolls-Royce RB211-524 series engines, which requires inspections, adjustments, and functional checks of the thrust reverser system, installation of a terminating modification, and repetitive operational checks of the gearbox locks and the air motor brake following accomplishment of the modification. (The service bulletin cited in that AD is Boeing Service Bulletin 767-78-0059, Revision 1, dated September 24, 1992.)

Difference Between the Proposed AD and Alert Service Bulletins

The alert service bulletins recommend incorporation of the specified actions “at the earliest maintenance opportunity when manpower, materials, and facilities are available,” the FAA finds that such a compliance time will not ensure that the modification is accomplished in a timely manner. In developing an appropriate compliance time for this AD, the FAA considered not only the manufacturer's recommendation, but the degree of urgency associated with addressing the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the modifications. In light of all of these factors, the FAA finds a 36-month compliance time for accomplishing the modifications on all affected airplanes to be warranted, in that it represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.

Cost Impact

There are approximately 1,654 airplanes of the affected design in the worldwide fleet. The FAA estimates that 583 Model 757 series airplanes and 292 Model 767 series airplanes of U.S. registry would be affected by this proposed AD. The work hours and cost estimates for the proposed modifications are listed below:

*Boeing Alert Service Bulletin 757-27A0130

Work package	Work hours @ $60/WH	Cost per airplane without parts	Fleet cost without parts
1	50	$3,000	$1,749,000
2	32	1,920	1,119,360
3	12	720	419,760
*Parts cost for Model 757 series airplanes is between $8,953 and $10,630 per airplane.

*Boeing Alert Service Bulletin 767-27A0160

Work package	Work hours @ $60/WH	Cost per airplane without parts	Fleet cost without parts
1	11	$660	$192,720
2	18	1,080	315,360
3	2	120	35,040
4	15	900	262,800
*Parts cost for Model 767 series airplanes is between $7,132 and $8,224 per airplane.

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.

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

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

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

§ 39.13

[Amended]

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

Boeing: Docket 2001-NM-75-AD.

Applicability: Model 757-200, -200CB, and -200PF series airplanes, line numbers 1 through 895 inclusive; and Model 767-200, -300, and -300F series airplanes, line numbers 1 through 759 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 (b) 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 provide a second air/ground signal to the auto-speedbrake control system to prevent uncommanded deployment of the auto-speedbrake spoilers during flight, which could result in reduced controllability of the airplane, accomplish the following:

Modifications

(a) Within 36 months after the effective date of this AD: Modify the right main landing gear and auto-speedbrake control system according to Work Packages 1 through 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 757-27A0130, dated August 31, 2000 (for Model 757 series airplanes), or Work Packages 1 through 4 of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-27A0160, dated December 20, 2000 (for Model 767 series airplanes), as applicable.

Note 2:

Boeing Alert Service Bulletin 757-27A0130 specifies that each work package can be done independently or at the same time, in any sequence, but the functional tests in Work Package 3 should be done last. Boeing Alert Service Bulletin 767-27A0160 specifies that each work package can be done independently or at the same time, in any sequence, but Work Package 4 should be done last.

Alternative Methods of Compliance

(b) 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.

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 Permit

(c) 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 November 20, 2001.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.