E6-16307. Airworthiness Directives; Boeing Model 777 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 all Boeing Model 777 airplanes. This proposed AD would require repetitive measurements of the freeplay of the right and left elevators, rudder, and rudder tab, and related investigative and corrective actions if necessary. This proposed AD would also require repetitive lubrications of the elevator, rudder, and rudder tab components. This proposed AD results from reports of freeplay-induced vibration of unbalanced control surfaces. Excessive freeplay of control surfaces can cause unacceptable airframe vibration during flight. The potential for vibration of the control surface should be avoided because the point of transition from vibration to divergent flutter is unknown. We are proposing this AD to prevent flutter, which can cause damage to the control surface structure and consequent loss of control of the airplane.

DATES:

We must receive comments on this proposed AD by November 17, 2006.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC 20590.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for the service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Dennis Stremick, Aerospace Engineer, Airframe Branch, ANM-120S, 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 submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2006-25973; Directorate Identifier 2006-NM-178-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Discussion

We have received reports of freeplay-induced vibration of unbalanced control surfaces on Boeing Model 727, 737, 757, and 767 airplanes. Excessive corrosion and wear of components and/or interfaces allows excessive freeplay movement of the control surfaces and can cause excessive vibration of the airframe during flight. The potential for vibration of the control surface should be avoided because the point of transition from vibration to divergent flutter is unknown. Flutter can cause damage to the control surface structure during flight. This condition, if not corrected, could result in loss of control of the airplane.

The control surfaces on Model 777 airplanes are similar to those on the affected Model 727, 737, 757, and 767 airplanes. Therefore, all of these models may be subject to the same unsafe condition.

Relevant Service Information

We have reviewed Boeing Special Attention Service Bulletin 777-27-0062, dated July 18, 2006. The service bulletin describes procedures for measuring the freeplay of the right and left elevators, rudder, and rudder tab. If the freeplay is greater than the given limit, the service bulletin specifies accomplishing related investigative and corrective actions to decrease the freeplay. The related investigative actions include inspecting for worn parts, which include hinges, bolts, actuator fittings, related bushings, power control unit (PCU) reaction links, kick link bearings, and hinge bolts. The corrective actions include replacing or repairing any worn parts; and repeating the freeplay measurement until the freeplay is less than the specified limits. The service bulletin also describes procedures for accomplishing repetitive lubrications of the elevator, rudder, and rudder tab components. Those components include hinge bearings for the elevators, rudder, and rudder tab; and reaction links and PCU rod ends for the elevators and rudder. The service bulletin also specifies doing the freeplay measurement before the lubrication, when the lubrication and freeplay measurement of a part are done during the same maintenance period.

For the initial measurement of the freeplay of the right and left elevators, rudder, and rudder tab, the service bulletin specifies that the measurements be done within 36 months after the date of the service bulletin, or within 36 months after the date of issuance of the original standard certificate of airworthiness or original export certificate of airworthiness, whichever occurs later. The service bulletin specifies a measurement repeat interval of 12,000 flight hours, or 36 months, whichever occurs first. The service bulletin also specifies that any corrective actions be done before further flight.

For the initial lubrication of the elevator, rudder, and rudder tab components, the service bulletin specifies that the lubrications be done within 16 months after the date of the service bulletin, or within 16 months after the date of issuance of the original standard certificate of airworthiness or original export certificate of airworthiness, whichever occurs later. The service bulletin specifies a lubrication repeat interval of 5,000 flight hours, or 16 months, whichever occurs first.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

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 service information described previously.

Costs of Compliance

There are about 695 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs, at an average labor rate of $80 per hour, for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Cost per airplane	Number of U.S.- registered airplanes	Fleet cost
Measurement of elevators, per measurement cycle	4	$320, per measurement cycle	145	$46,400, per measurement cycle.
Lubrication of elevators, per lubrication cycle	17	$1,360, per lubrication cycle	145	$197,200, per lubrication cycle.
Measurement of rudder, per measurement cycle	4	$320, per measurement cycle	145	$46,400, per measurement cycle.
Lubrication of rudder, per lubrication cycle	7	$560, per lubrication cycle	145	$81,200, per lubrication cycle.
Measurement of rudder tab, per measurement cycle	3	$240, per measurement cycle	145	$34,800, per measurement cycle.
Lubrication of rudder tab, per lubrication cycle	5	$400, per lubrication cycle	145	$58,000, per lubrication cycle.

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-2006-25973; Directorate Identifier 2006-NM-178-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by November 17, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to all Boeing Model 777-200, -200LR, -300, and -300ER series airplanes, certificated in any category.

Unsafe Condition

(d) This AD results from reports of freeplay-induced vibration of unbalanced control surfaces. Excessive freeplay of control surfaces can cause unacceptable airframe vibration during flight. The potential for vibration of the control surface should be avoided because the point of transition from vibration to divergent flutter is unknown. We are issuing this AD to prevent flutter, which can cause damage to the control surface structure and consequent 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.

Repetitive Measurements

(f) At the applicable times specified in Tables 1, 2, and 3 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 777-27-0062, dated July 18, 2006, except as provided by paragraph (i) of this AD: Measure the freeplay of the right and left elevators, rudder, and rudder tab; and do all related investigative and corrective actions before further flight; by accomplishing all the actions specified in Parts 1, 3, and 5 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-27-0062, dated July 18, 2006, as applicable. Repeat the measurements and related investigative and corrective actions thereafter at the interval specified in Table 1, 2, or 3 of the service bulletin, as applicable.

Repetitive Lubrications

(g) At the applicable times specified in Tables 1, 2, and 3 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 777-27-0062, dated July 18, 2006, except as provided by paragraph (i) of this AD: Lubricate the elevator components, rudder components, and rudder tab components, by accomplishing all the actions specified Parts 2, 4, and 6 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-27-0062, dated July 18, 2006, as applicable. Repeat the lubrications thereafter at the interval specified in Table 1, 2, or 3 of the service bulletin, as applicable.

Concurrent Compliance Times

(h) If a freeplay measurement of a specified part required by paragraph (f) of this AD and a lubrication of the same part required by paragraph (g) of this AD are due at the same time or will be accomplished during the same maintenance visit, the freeplay measurement and all related investigative and corrective actions must be done before the lubrication is accomplished.

Exceptions to Compliance Times

(i) Where Boeing Special Attention Service Bulletin 777-27-0062, dated July 18, 2006, recommends an initial compliance threshold of “Within 36 months after the date on this service bulletin” for Parts 1, 3, and 5 of the service bulletin, this AD requires an initial compliance threshold of “within 36 months after the effective date of this AD.” Where Boeing Special Attention Service Bulletin 777-27-0062, dated July 18, 2006, recommends an initial compliance threshold of “Within 16 months after the date on this service bulletin” for Parts 2, 4, and 6 of the service bulletin, this AD requires an initial compliance threshold of “within 16 months after the effective date of this AD.”

Alternative Methods of Compliance (AMOCs)

(j)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

Issued in Renton, Washington, on September 26, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.