E8-11286. Airworthiness Directives; Boeing Model 757-200 and -200PF Series Airplanes, and Model 767-200 and -300 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 757-200 and -200PF series airplanes; and Model 767-200 and -300 series airplanes. This proposed AD would require doing an inspection to determine the part number and serial number of the hub assembly of the ram air turbine (RAT), and replacing the hub assembly of the RAT with a new, serviceable, or reworked and re-identified hub assembly if necessary. This proposed AD results from reports indicating that the counterweights in some hub assemblies of the RATs could be under strength and fracture when they are extended in flight. We are proposing this AD to prevent a fractured counterweight on the hub assembly of the RAT, which will cause an overspeed condition, and consequent turbine blade separation, possible injury to passengers, possible airplane structural damage, and an inoperative RAT. An inoperative RAT will cause the loss of hydraulic power to the primary flight controls in cases where both engines are shut down in flight, resulting in subsequent loss of control of the airplane.

DATES:

We must receive comments on this proposed AD by July 7, 2008.

ADDRESSES:

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: [phone].
• 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 [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Kenneth Frey, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

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-2008-0561; Directorate Identifier 2007-NM-223-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, 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.

Discussion

We have received reports indicating that the counterweights in some hub assemblies of the ram air turbine (RAT) could be under strength and fracture when they are extended in flight, on certain Boeing Model 757-200 and -200PF series airplanes and Model 767-200 and -300 series airplanes. The cause of the fractures has been attributed to a manufacturing process error. A fractured counterweight on the hub assembly of the RAT, if not corrected, will cause an overspeed condition, and consequent turbine blade separation, possible injury to passengers, possible airplane structural damage, and an inoperative RAT. An inoperative RAT will cause the loss of hydraulic power to the primary flight controls in cases where both engines are shut down in flight, resulting in subsequent loss of control of the airplane.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 757-29A0066, dated January 2, 2007 (for Model 757-200 and -200PF series airplanes); and Boeing Alert Service Bulletin 767-29A0110, dated January 2, 2007 (for Model 767-200 and -300 series airplanes). The service bulletins describe procedures for doing an inspection to determine the part number and serial number on the hub assembly of the RAT, replacing the hub assembly of the RAT with a new, serviceable, or reworked and re-identified hub assembly if necessary, and submitting a report to the manufacturer. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

Boeing Alert Service Bulletin 757-29A0066, refers to the Hamilton Sundstrand Service Bulletin 730814-29-12, dated November 30, 2005; and Boeing Alert Service Bulletin 767-29A0110, refers to the Hamilton Sundstrand Service Bulletin 729548-29-15, dated November 30, 2005; as additional sources of service information for accomplishing the inspection and replacement of the hub assembly of the RAT.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the Boeing service information described previously, except as discussed under “Difference between the Proposed Rule and Referenced Service Bulletin.”

Difference Between Proposed Rule and Referenced Service Bulletin

Operators should note that, although the Accomplishment Instructions of the referenced Boeing service bulletins describe procedures for submitting a feedback form related to the service bulletins, this proposed AD would not require those actions.

Costs of Compliance

There are about 60 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 43 airplanes of U.S. registry. The proposed inspection would take about 1 work hour per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $3,440, or $80 per airplane.

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.

Regulatory Findings

We have 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 that the 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2008-0561; Directorate Identifier 2007-NM-223-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by July 7, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing airplanes identified in Table 1 of this AD, certified in any category.

Table 1.—Applicability

For model—	As identified in—
(1) 757-200 and -200PF series airplanes	Boeing Alert Service Bulletin 757-29A0066, dated January 2, 2007.
(2) 767-200 and -300 series airplanes	Boeing Alert Service Bulletin 767-29A0110, dated January 2, 2007.

Unsafe Condition

(d) This AD results from reports indicating that the counterweights in some hub assemblies of the ram air turbines (RAT) could be under strength and fracture when they are extended in flight. We are issuing this AD to prevent a fractured counterweight on the hub assembly of the RAT, which will cause an overspeed condition, and consequent turbine blade separation, possible injury to passengers, possible airplane structural damage, and an inoperative RAT. An inoperative RAT will cause the loss of hydraulic power to the primary flight controls in cases where both engines are shut down in flight, resulting in subsequent loss of control of the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Inspection and Replacement

(f) Within 24 months after the effective date of this AD, do an inspection to determine the part number and serial number on the hub assembly of the RAT in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 757-29A0066, dated January 2, 2007 (for Model 757-200 and -200PF series airplanes); or Boeing Alert Service Bulletin 767-29A0110, dated January 2, 2007 (for Model 767-200 and -300 series airplanes); as applicable. If the part number and serial number on the hub assembly of the RAT are listed in Table 2 of this AD, within 24 months after the effective date of this AD, replace the hub assembly of the RAT with a new, serviceable, or reworked and re-identified hub assembly, in accordance with the Accomplishment Instructions of the service bulletin.

Parts Installation

(g) As of the effective date of this AD, no person may install a hub assembly of the RAT having any applicable part number and serial number listed in Table 2 of this AD, on any airplane, unless it has been reworked and re-identified in accordance with paragraph (f) of this AD.

Table 2.—RAT Hub Assembly Part Numbers

For model—	Part No.—	Serial No.—
(1) 757-200 and -200PF series airplanes	733785A or 733785B	0410 through 0413 inclusive, 0415, 0417 through 0430, 0432, or 0434.
(2) 767-200 and -300 series airplanes	734350A, 734350B, 734350C, or 734350D	0666, 0673 through 0684 inclusive, 0686, 0687, or 0689.

No Information Submission

(h) Although Boeing Alert Service Bulletin 757-29A0066, dated January 2, 2007 (for Model 757-200 and -200PF series airplanes); and Boeing Alert Service Bulletin 767-29A0110, dated January 2, 2007 (for Model 767-200 and -300 series airplanes); specify to submit information to the manufacturer, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with 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 May 7, 2008.

Michael J. Kaszycki,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.