Federal Aviation Administration (FAA), DOT.
Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.
We are revising an earlier proposed airworthiness directive (AD) for certain Boeing Model 767 airplanes. The original NPRM would have required modifying the link arms of the number 2 windows in the flight compartment. The original NPRM resulted from reports of the number 2 windows opening during takeoff roll, which has resulted in aborted takeoffs. This supplemental NPRM would require an inspection of the number 2 windows to determine whether the link arms are in the over-center position. The results of the inspection would determine the need for the modification. This supplemental NPRM would also require the inspection and applicable corrective action following any rigging change or replacement of any number 2 window assembly. We are proposing this supplemental NPRM to prevent the opening of the number 2 windows during takeoff roll, which could result in an aborted takeoff or an unscheduled landing, and adversely affect the flightcrew's ability to perform critical takeoff communication.
We must receive comments on this supplemental NPRM by December 16, 2008.
You may send comments by any of the following methods:
- Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
- Fax: 202-493-2251.
- Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
- Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Emerson Hevia, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6414; fax (425) 917-6590.End Further Info End Preamble Start Supplemental Information
We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2007-27223; Directorate Identifier 2006-NM-224-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, Start Printed Page 70609economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.
We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.
We issued a notice of proposed rulemaking (NPRM) (the “original NPRM”) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Boeing Model 767 airplanes. That original NPRM was published in the Federal Register on February 14, 2007 (72 FR 6980). That original NPRM proposed to require modifying the link arms of the number 2 windows in the flight compartment.
Actions Since Original NPRM Was Issued
Since we issued the original NPRM, the referenced service bulletin (Boeing Alert Service Bulletin 767-56A0010, dated September 7, 2006) was determined to inadequately address the need for the link arm to be positioned at an angle less than 90 degrees (over-center), in reference to the track roller, when the window is closed. Boeing has since revised the service bulletin. Revision 1, dated January 24, 2008, adds instructions to inspect the link arm on the number 2 openable window to determine if an over-center position exists when the window is fully closed. This inspection will determine the need for the modification described in the original service bulletin (and described previously in the original NPRM). The modification, if done, will ensure that the window cannot open without input from the operating crank as designed. Accomplishment of the actions specified in this service bulletin will reduce the risk of a high-speed rejected takeoff if the window opens at takeoff. Aside from other minor changes, the remaining procedures in the service bulletin are unchanged.
We gave the public the opportunity to participate in developing this AD. We considered the comments received.
Request To Withdraw NPRM
Florida West International Airways feels that proposed modification is not necessary. According to the commenter, the windows can be prevented from opening during takeoff roll if the crew follows the normal Before Start checklist in the FAA-approved operations manual. The checklist directs the crew to physically check that the windows are closed. Florida West reports that its crews observe this requirement and have not experienced this problem even when the windows are opened on the ground during aircraft maintenance. Florida West suggests that some operational experience with the new modified window—before the modification is mandated on the rest of the fleet—will ensure that the solution addresses the unsafe condition, and avoid further regulatory action.
We infer that the commenter is requesting that we withdraw the NPRM. We disagree. Even though proper closure of the window has been added to the preflight checklist, we have continued to receive problem reports. We find that the modification, as proposed, will better ensure long-term continued operational safety by design changes to remove the source of the problem, rather than by relying on flight procedures and their inherent associated human factors (variations in flightcrew training and familiarity with the airplane, flightcrew awareness in the presence of other hazards, flightcrew fatigue, etc.). So in this case reliance on the checklist would not provide the degree of safety assurance necessary for the transport airplane fleet. The requirements, as proposed, are consistent with these conditions. We have not changed the AD regarding this issue.
Request To Provide Different Approach To Address Unsafe Condition
Air Transport Association (ATA), on behalf of its member Delta Air Lines, suggests two ideas that could positively improve the level of safety:
1. An electrical annunciation means of an improperly latched and/or locked window.
2. Increased awareness of proper operating procedures plus a visual means to verify that the upper aft cam follower has reached full forward travel into the cam block before the window is locked. Delta suggests that this could be accomplished by adding match lines visible through the cam block cover or making a clear cover over the cam block.
Delta explains that, if the cam follower has reached full travel into the cam block, the window is properly closed and can then be properly locked. Delta adds that the modification proposed in the NPRM would not increase the level of safety because the window is not properly in the hole until the upper aft cam has reached full travel in the cam block. Delta further adds that the position of the window must be verified prior to dispatch, but the modification procedures do not include this verification.
We disagree with Delta's proposals, which would not enhance safety beyond the level provided by the proposed design modification specified in the NPRM, which prevents the window from opening when the crank is rotated to the closed position. An electronic indication system through the Engine Indicating and Crew Alerting System (EICAS) was evaluated and was determined to not be cost effective. Operational procedures should also be in place to verify that the window is closed for taxi/takeoff. As previously discussed, even though verification has been added to the preflight checklist, we have continued to receive problem reports. Additional indicators or procedures would not improve safety if the modification did not prevent the window from opening. If an indicator were installed to verify that the window was closed, but the window opened inadvertently during takeoff, then the level of safety is not improved. Accomplishment of the modification as proposed will ensure that the window cannot open during takeoff, and will adequately address the unsafe condition. We have not changed the supplemental NPRM regarding this issue.
FAA's Determination and Proposed Requirements of the Supplemental NPRM
We are proposing this supplemental NPRM because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design. The additional proposed actions described above expand the scope of the original NPRM. As a result, we have determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this supplemental NPRM.
Costs of Compliance
There are about 896 airplanes of the affected design in the worldwide fleet; of these, 384 are U.S.-registered airplanes. The following table provides the estimated costs for U.S. operators to comply with this proposed AD. Start Printed Page 70610
|Action||Work hours||Average labor rate per hour||Cost per airplane||Fleet cost|
|Inspection||1||$80||$80||Up to $30,720.|
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. “Subtitle VII: Aviation Programs” describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in “Subtitle VII, Part A, Subpart III, section 44701: General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.
We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.
For the reasons discussed above, I certify 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. 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.
You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.Start List of Subjects
List of Subjects in 14 CFR Part 39End List of Subjects
The Proposed Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. The FAA amends § 39.13 by adding the following new AD:
BOEING: Docket No. FAA-2007-27223; Directorate Identifier 2006-NM-224-AD.
Comments Due Date
(a) We must receive comments by December 16, 2008.
(c) This AD applies to Model 767-200, -300, -300F, and -400ER series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 767-56A0010, Revision 1, dated January 24, 2008.
(d) This AD results from reports of the number 2 windows in the flight compartment opening during takeoff roll, which has resulted in aborted takeoffs. We are issuing this AD to prevent the opening of the number 2 windows during takeoff roll, which could result in an aborted takeoff or an unscheduled landing, and adversely affect the flightcrew's ability to perform critical takeoff communication.
(e) Comply with this AD within the compliance times specified, unless already done.
(f) Do a general visual inspection of the number 2 windows to determine whether the link arms are in the over-center position, and do all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 767-56A0010, Revision 1, dated January 24, 2008. Do the actions at the applicable times specified in paragraph 1.E. of the service bulletin, including applicable corrective actions before further flight following any rigging change or replacement of any number 2 window assembly.
Alternative Methods of Compliance (AMOCs)
(g)(1) The Manager, Seattle Aircraft Certification Office, FAA, ATTN: Emerson Hevia, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6414; fax (425) 917-6590; has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.
(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.
Issued in Renton, Washington on November 6, 2008.
Stephen P. Boyd,
Assistant Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. E8-27519 Filed 11-20-08; 8:45 am]
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