E6-1944. Airworthiness Directives; Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Boeing Model 747-400, 747-400D, and 747-400F series airplanes. The existing AD currently requires reviewing airplane maintenance records; inspecting the yaw damper actuator portion of the upper and lower rudder power control modules (PCM) for cracking, and replacing the PCMs if necessary; and reporting all airplane maintenance records review and inspection results to the manufacturer. This proposed AD would expand the applicability and discontinue certain requirements of the existing AD. This proposed AD would require repetitive inspections of the PCMs and replacement of the PCMs if necessary. This proposed AD results from manufacturer findings that the inspections required by the existing AD must be performed at regular intervals. We are proposing this AD to detect and correct cracking in the yaw damper actuator portion of the upper and lower rudder PCMs, which could result in an uncommanded left rudder hardover, consequent increased pilot workload, and possible runway departure upon landing.

DATES:

We must receive comments on this proposed AD by March 30, 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.

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

FOR FURTHER INFORMATION CONTACT:

Douglas Tsuji, 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

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2006-23873; Directorate Identifier 2005-NM-110-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 our docket 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 can review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.

Examining the Docket

You can 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 (DMS) receives them.

Discussion

On November 3, 2003, we issued AD 2003-23-01, amendment 39-13364 (68 FR 64263, November 13, 2003), for certain Boeing Model 747-400, 747-400D, and 747-400F series airplanes. That AD requires reviewing airplane maintenance records; inspecting the yaw damper actuator portion of the upper and lower power control modules (PCM) for cracking, and replacing the PCMs if necessary; and reporting airplane maintenance records review and inspection results to the manufacturer. That AD was prompted by a report that the lower rudder of a Boeing Model 747-400 series airplane made an uncommanded move to the full left position (hardover) during flight. We issued that AD to detect and correct cracking in the yaw damper actuator portion of the upper and lower rudder PCMs, which could result in an uncommanded left rudder hardover, consequent increased pilot workload, and possible runway departure upon landing.

Actions Since Existing AD Was Issued

The preamble to AD 2003-23-01 explains that we consider the requirements “interim action.” The inspection reports required by that AD were intended to enable the manufacturer and the FAA to obtain better insight into the nature, cause, and extent of the cracking, and eventually to develop final action to address the unsafe condition. We now have determined that further rulemaking is necessary, and this proposed AD follows from that determination.

Since we issued AD 2003-23-01, there have been no further reports of a failure of the yaw damper actuator portion of the lower rudder PCM manifold. Also, investigations that included inspection results gathered during accomplishment of the original release of Boeing Alert Service Bulletin 747-27A2397, dated July 24, 2003 (which is referenced as the appropriate source of service information for doing the actions required by AD 2003-23-01), did not yield any explanation as to the cause of the cracks in the yaw damper actuator portion of the lower rudder PCM manifold. However, the failure that led to the issuance of AD 2003-23-01 highlighted a previously unidentified single point failure. Without inspection of the yaw damper actuator portion of the lower rudder PCM manifold, a developing crack can remain latent and grow to the point of failure. Therefore, to ensure that no latent crack can develop undetected to the point of failure of the PCM manifold, it has been determined that regular repetition of the inspection required by AD 2003-23-01 is necessary for all Boeing Model 747-400, 747-400D, and 747-400F series airplanes.

The compliance time for the initial inspection (for airplanes not previously inspected as required by AD 2003-23-01) has been revised to the earlier of 56,000 total flight hours or 9,000 total flight cycles, or, for airplanes that are close to or have exceeded that total, 24 months after the effective date of the AD. This compliance time is based on the data gathered from airplanes inspected in accordance with AD 2003-23-01, including the fact that there have been no further reports of a failure of the yaw damper actuator portion of the lower rudder PCM manifold. We find that this initial compliance time will be adequate to ensure the safety of the affected airplane fleet.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 747-27A2397, Revision 1, dated March 31, 2005. The service bulletin describes procedures for performing repetitive ultrasonic inspections for cracking of the yaw damper actuator portion of the upper and lower rudder PCMs; reporting the finding of any indication of a cracked or broken PCM to the airplane manufacturer; and returning any cracked or broken part to the PCM manufacturer.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to develop on other airplanes of the same type design. For this reason, we are proposing this AD, which would supersede AD 2003-23-01. This proposed AD would expand the applicability of the existing AD and require accomplishing all actions specified in Boeing Alert Service Bulletin 747-27A2397, Revision 1, described previously.

Clarification of Alternative Method of Compliance (AMOC) Paragraph

We have revised this action to clarify the appropriate procedure for notifying the principal inspector before using any approved AMOC on any airplane to which the AMOC applies.

Costs of Compliance

There are approximately 636 airplanes of the affected design in the worldwide fleet. The FAA estimates that 86 airplanes of U.S. registry would be affected by this proposed AD, and that it would take approximately 4 work hours per airplane to accomplish the ultrasonic inspection, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the inspection is estimated to be $22,360, or $260 per airplane, per inspection 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. 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 FAA amends § 39.13 by removing amendment 39-13364 (68 FR 64263, November 13, 2003) and adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2006-23873; Directorate Identifier 2005-NM-110-AD.

Comments Due Date

(a) The Federal Aviation Administration must receive comments on this AD action by March 30, 2006.

Affected ADs

(b) This AD supersedes AD 2003-23-01.

Applicability

(c) This AD applies to all Boeing Model 747-400, 747-400D, and 747-400F series airplanes, certificated in any category.

Unsafe Condition

(d) This AD results from manufacturer findings that the inspections required by AD 2003-23-01 must be performed at regular intervals. We are issuing this AD to detect and correct potential cracking in the yaw damper actuator portion of the upper and lower rudder power control modules (PCM), which could result in an uncommanded left rudder hardover, consequent increased pilot workload, and possible runway departure upon landing.

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.

Verification of Rudder PCM/Main Manifold Time in Service

(f) For any affected airplane, if it can be positively verified that any rudder PCM or PCM main manifold installed on that airplane has accumulated a different total of flight hours or flight cycles than the totals accumulated by that airplane, the flight cycles or flight hours accumulated by the rudder PCM or PCM main manifold will be acceptable as valid starting points for meeting the compliance times required by this AD.

Inspection Accomplished Prior to the Issuance of This AD

(g) For airplanes which, prior to the effective date of this AD, have received an ultrasonic inspection for cracking of the yaw damper actuator portion of the upper and lower rudder PCM, in accordance with Boeing Alert Service Bulletin 747-27A2397, dated July 24, 2003, as required by AD 2003-23-01, do paragraphs (g)(1), (g)(2), (g)(3), and (g)(4) of this AD, as applicable, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-27A2397, Revision 1, dated March 31, 2005.

(1) Perform the ultrasonic inspection described in paragraph (g) of this AD at the later of the times specified in paragraph (g)(1)(i) or (g)(1)(ii) of this AD, then do paragraph (g)(2) or (g)(3) of this AD, as applicable; and paragraph (g)(4) of this AD.

(i) Within 28,000 flight hours or 4,500 flight cycles after the date of the prior inspection, whichever occurs first.

(ii) Within 24 months after the effective date of this AD.

(2) If no cracking is found during any inspection required by paragraph (g)(1) or (h) of this AD: Apply sealant and a torque stripe and install a lockwire on the rudder PCM in accordance with the Accomplishment Instructions and Figure 1 or Figure 2, as applicable, of Alert Service Bulletin 747-27A2397, Revision 1.

(3) If any cracking is found during any inspection required by paragraph (g)(1) or (h) of this AD: Before further flight, replace the affected PCM with a new or serviceable PCM and submit the report required by paragraph (i) of this AD.

(4) Repeat the ultrasonic inspection described in paragraph (g) of this AD at intervals not to exceed 28,000 flight hours or 4,500 flight cycles, whichever occurs first, and repeat the actions of paragraph (g)(2) or (g)(3) of this AD, as applicable.

Initial Inspection

(h) For airplanes not inspected prior to the effective date of this AD as specified in paragraph (g) of this AD: At the later of the times specified in paragraph (h)(1) or (h)(2) of this AD, perform an ultrasonic inspection for cracking of the yaw damper actuator portion of the upper and lower rudder PCM main manifold; and the actions specified in paragraph (g)(2) or (g)(3) of this AD, as applicable; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-27A2397, Revision 1, dated March 31, 2005. Repeat the inspection thereafter at intervals not to exceed 28,000 flight hours or 4,500 flight cycles, whichever occurs first.

(1) Prior to the accumulation of 56,000 total flight hours or 9,000 total flight cycles, whichever occurs first.

(2) Within 24 months after the effective date of this AD.

Reporting Requirements and Damaged Parts Disposition

(i) For all airplanes: At the applicable time specified in paragraph (i)(1) or (i)(2) of this AD, accomplish paragraph (j) of this AD.

(1) If the inspection was done after the effective date of this AD: Submit the report and part, if applicable, within 30 days after the inspection.

(2) If the inspection was done before the effective date of this AD: Submit the report and part, if applicable, within 30 days after the effective date of this AD.

(j) At the applicable time specified in paragraph (i) of this AD: Do the requirements of paragraphs (j)(1) and (j)(2) of this AD. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.

(1) If any inspection required by this AD reveals any indication of a cracked or broken part, submit a report to: The Boeing Company, Service Engineering—Mechanical Systems. The report must contain the airplane and rudder PCM serial numbers, the total flight hours and flight cycles for each rudder PCM (and rudder PCM main manifold, if known), and a description of any damage found. Submission of the Inspection Report Form (Figure 3 of Boeing Alert Service Bulletin 747-27A2397, Revision 1, dated March 31, 2005) is one acceptable method of complying with this requirement.

(2) Send any cracked or broken PCMs to Parker Hannifin Corporation in accordance with the shipping instructions specified in Appendix A of Boeing Alert Service Bulletin 747-27A2397, Revision 1.

Prior Accomplishment of Requirements

(k) Actions accomplished before the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-27A2397, dated July 24, 2003, shall be considered acceptable for compliance with the corresponding requirements of this AD.

Parts Installation

(l) As of the effective date of this AD, no person shall install on any airplane a rudder PCM having part number (P/N) 332700-1003, -1005, -1007, or -1009; or P/N 333200-1003, -1005, -1007, or -1009; unless the PCM has been ultrasonically inspected (either by the operator or the supplier) in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-27A2397, Revision 1, dated March 31, 2005.

Alternative Methods of Compliance (AMOCs)

(m)(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 14 CFR 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) AMOCs approved previously according to AD 2003-23-01, amendment 39-13364, are approved as AMOCs with this AD.

Issued in Renton, Washington, on January 31, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.