Federal Register: March 3, 2005 (Volume 70, Number 41)

DOCID: FR Doc 05-4080

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

CFR Citation: 14 CFR Part 39

Docket ID: [Docket No. FAA-2005-20473; Directorate Identifier 2004-NM-156-AD]

RIN ID: RIN 2120-AA64

NOTICE: PROPOSED RULES

ACTION: Airworthiness directives:

DOCUMENT ACTION: Notice of proposed rulemaking (NPRM).

SUBJECT CATEGORY:

Airworthiness Directives; Boeing Model 757-200, -200PF, and -300 Series Airplanes

DATES: We must receive comments on this proposed AD by April 18, 2005.

DOCUMENT SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 757200, 200PF, and 300 series airplanes. This proposed AD would require inspecting for damage of the ground brackets, ground wires, and terminal lugs of the auxiliary power unit (APU) battery and the APU start transformer rectifier unit (TRU) as applicable; and corrective and related investigative actions. This proposed AD is prompted by reports indicating that, during inspections on two airplanes, the ground brackets for the APU battery were found damaged. We are proposing this AD to detect and correct a damaged electrical bonding surface of the APU battery and APU start TRU ground connections, which could cause overheating of the ground connections and lead to possible consequent ignition of the adjacent insulating blankets.

SUMMARY:

Boeing,

SUPPLEMENTAL 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. FAA200520473; Directorate Identifier 2004NM156AD'' in the subject line 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 submitted 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 can review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 1947778), 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 (800) 647 5227) 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 DMS receives them. Discussion

We have received reports indicating that, during inspections on two Boeing Model 757200 airplanes, the ground brackets for the auxiliary power unit (APU) battery were found damaged. Manufacturer analysis found that the bonding surface of the ground brackets had an anodized finish, which reduces electrical conductivity. Further manufacturer investigation of airplanes in production revealed that the method used to clean the ground brackets didn't remove the anodized finish from the bonding surface before the ground wires were installed. This condition, if not corrected, could cause overheating of the ground connections and lead to possible consequent ignition of the adjacent insulating blankets.

Similar Models

The subject ground brackets on certain Boeing Model 757200PF and 300 airplanes are almost identical to those on the affected Model 757 200 airplanes. Therefore, all of these models may be subject to the same unsafe condition.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 75724A0099 (for Model 757200 and 200PF series airplanes), and Alert Service Bulletin 75724A0100 (for Model 757300 series airplanes); both dated March 25, 2004. The service bulletins describe procedures for inspecting the ground brackets, ground wires, and terminal lugs of the APU battery and the APU start transformer rectifier unit (TRU) ground connections; and corrective and related investigative actions. Corrective actions include cleaning the bonding surfaces of the ground brackets and terminal lugs; and replacing the ground brackets, ground wires, and terminal lugs if necessary. Investigative actions include measuring the electrical resistance between the ground brackets and the terminal lugs and between the ground brackets and the station frame. 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. Therefore, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously.

Clarification of Inspection Terminology

The Boeing alert service bulletins specify inspecting for damage to certain ground connections, but do not specify the type of inspection to be performed. Paragraph (f) of this proposed AD identifies this inspection as a ``general visual inspection,'' and Note 1 of this proposed AD defines this inspection.

Costs of Compliance

There are about 251 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 159 airplanes of U.S. registry.

For about 95 Group 1 and Group 3 airplanes: The proposed inspection and cleaning of the ground connections would take about 2 work hours per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $12,350, or $130 per airplane.

For about 64 Group 2 airplanes: The proposed inspection and cleaning of the ground connection would take about 1 work hour per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $4,160, or $65 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,
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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 39AIRWORTHINESS DIRECTIVES

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

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

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD):
Boeing: Docket No. FAA200520473; Directorate Identifier 2004NM 156AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive comments on this AD action by April 18, 2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 757200, 200PF, and 300 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 75724A0099, and Boeing Alert Service Bulletin 75724A0100; both dated March 25, 2004.
Unsafe Condition
(d) This AD was prompted by reports indicating that during inspections on two airplanes, the ground brackets for the auxiliary power unit (APU) battery were found damaged. We are issuing this AD to detect and correct a damaged electrical bonding surface of the APU battery and APU start transformer rectifier unit (TRU) ground connections, which could cause overheating of the ground connections and lead to possible consequent ignition of the adjacent insulating blankets.
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 of Ground Connections
(f) Within 18 months after the effective date of this AD, perform a general visual inspection for damage of the ground brackets, ground wires, and terminal lugs of the APU battery and APU start transformer rectifier unit (TRU), and do any corrective and related investigative actions; by doing all the actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 75724A0099 (for Model 757200 and 200PF series airplanes), or Boeing Alert Service Bulletin 75724A0100 (for Model 757300 series airplanes); both dated March 25, 2004; as applicable.

Note 1: For the purposes of this AD, a general visual inspection is ``a visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normal available lighting conditions such as daylight, hangar lighting, flashlight or drop light and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked.''
Alternative Methods of Compliance (AMOCs)
(g) 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.

Issued in Renton, Washington, on February 18, 2005. Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 054080 Filed 3205; 8:45 am]
BILLING CODE 491013P

FOR FURTHER INFORMATION CONTACT

Elias Natsiopoulos, Aerospace Engineer, Systems and Equipment Branch, ANM130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055 4056; telephone (425) 9176478; fax (425) 9176590.