03-10515. Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes. This proposal would require a one-time inspection of the potable water and drain lines in the forward and aft cargo compartments for indications of overheating of the heater tape, exposed foam insulation, missing or damaged protective tape, or debris around the potable water fill and drain lines; and corrective action, if necessary. This action is necessary to prevent overheating of the heater tape on potable water fill and drain lines, which may ignite accumulated debris or contaminants on or near the potable water fill and drain lines, resulting in a fire in the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by June 13, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-341-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-341-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Donald Eiford, 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

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2002-NM-341-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-341-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received a report of a fire in the aft cargo compartment of a Boeing Model 767 series airplane. The fire was detected and extinguished. Investigation by the operator of the airplane indicated that heater tape on a water fill line overheated, igniting debris accumulated on or near the heater tape. The operator inspected several other airplanes and found heater tape that failed a continuity test, evidence of heat damage on foam insulation or protective tape, and accumulated debris on or near heater tape on potable water fill and drain lines in both the forward and aft cargo compartments. The combination of failed heater tape on the potable water fill and drain lines and the accumulation of ignitable debris or contamination on or near one of those lines may lead to a fire in the airplane. Model 747 series airplanes have a similar configuration to that of the Model 767 and, under similar conditions, are subject to the same unsafe condition.

Related Rulemaking

On May 29, 2002, the FAA issued AD 2002-11-11, amendment 39-12772 (67 FR 39265, June 7, 2002), for certain Boeing Model 767-200, -300, and -300F series airplanes to require a one-time inspection of the potable water and drain lines in the forward and aft cargo compartments for indications of overheating of the heater tape, exposed foam insulation, missing or damaged protective tape, or debris around the potable water fill and drain lines; and corrective action, if necessary. As indicated in that AD, the FAA has been investigating the extent to which the heater tape addressed in that AD is used on other Boeing airplane models. Based on the results of that investigation, the FAA has determined that additional rulemaking is necessary for certain Model 747 series airplanes. The unsafe condition and required actions of AD 2002-11-11 are identical to those specified in this proposed AD.

AD 2002-11-11 was issued as an immediately adopted rule. The FAA has re-evaluated the urgency associated with the identified unsafe condition and determined that it is practicable to provide notice and the opportunity for public comment on this proposed rule for certain Model 747 series airplanes.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 747-30A2079, dated December 12, 2002, which describes procedures for the following actions:

• One-time inspection of visually accessible areas in the forward and aft cargo compartments for accumulated debris and contaminants on or near the potable water fill and drain lines, and removal of any debris or contaminants found.
• One-time inspection of visually accessible portions of the potable water fill and drain lines in the forward and aft cargo compartments for indications of overheating of the heater tape, and replacement of heater tape where such indications are found.
• One-time inspection of visually accessible portions of the potable water fill and drain lines in the forward and aft cargo compartments for missing or damaged protective tape or exposed foam insulation, and replacement of any missing or damaged protective tape.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously.

Interim Action

This is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.

Cost Impact

There are approximately 1,129 airplanes (968 passenger and 161 freighter) of the affected design in the worldwide fleet. The FAA estimates that 250 airplanes of U.S. registry would be affected by this proposed AD. The FAA provides the following cost estimates associated with this proposed AD:

Cost Estimates

Type of airplane	Work hours	Hourly labor rate	Parts cost	Cost per airplane	Number of airplanes	Fleet cost
Freighter	10	$60	$0	$600	35	$21,000
Passenger	20	60	0	1,200	215	258,000

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness directive:

Boeing: Docket 2002-NM-341-AD.

Applicability: Model 747 series airplanes, certificated in any category, with lower cargo floors (floors in the lower cargo areas) that are not fully enclosed. A fully enclosed cargo floor is a floor with panels installed between all roller trays in the cargo compartment. A cargo floor that is not fully enclosed is a floor without panels installed between all roller trays in the cargo compartment.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent overheating of the heater tape on potable water fill and drain lines, which may ignite accumulated debris or contaminants on or near the potable water fill and drain lines, resulting in a fire in the airplane, accomplish the following:

Debris Removal

(a) At the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD: Perform a one-time general visual inspection for foreign object debris (FOD) and contamination in visually accessible areas on or near potable water and drain lines located below the cargo floor in the forward and aft cargo compartments, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-30A2079, dated December 12, 2002. Remove any FOD or contamination observed on or near the potable water or drain lines before further flight in accordance with the service bulletin.

(1) Inspect within 18 months since the date of issuance of the original Airworthiness Certificate or within 18 months since the date of issuance of the Export Certificate of Airworthiness, whichever occurs first; or

(2) Inspect within 90 days after the effective date of this AD.

Note 2:

The inspection of potable water and drain lines in visually accessible areas does not require removal of floor panels.

Note 3:

For the purposes of this AD, a general visual inspection is defined as: “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 enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight 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.”

Inspection for Discrepant Heater Tape

(b) At the applicable time specified in paragraph (c) of this AD: Perform a general visual inspection for discrepancies of visually accessible areas of potable water and drain lines located below the cargo floor in the forward and aft cargo compartments, as specified in paragraphs (b)(1) and (b)(2) of this AD, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-30A2079, dated December 12, 2002.

(1) Inspect potable water and drain lines for indications of overheating of the heater tape, including localized darkening of foam insulation or protective tape. If overheating is observed: Prior to further flight, replace the defective heater tape in accordance with the service bulletin, removing floor panels as necessary to replace the defective heater tape.

(2) Inspect potable water and drain lines for exposed foam insulation and missing or damaged protective tape. If exposed foam insulation is observed: Prior to further flight, cover the foam insulation with a continuous wrap of protective tape, in accordance with the service bulletin. If protective tape is missing or damaged: Prior to further flight, replace the protective tape in accessible areas in accordance with the service bulletin. It is not necessary to remove floor panels to replace the protective tape.

(c) Do the inspection required by paragraph (b) at the later of the times specified in paragraphs (c)(1) and (c)(2) of this AD.

(1) Within 18 months since the date of issuance of the original Airworthiness Certificate or the date of issuance of the Export Certificate of Airworthiness, whichever occurs first.

(2) Within 90 days after the effective date of this AD.

Alternative Methods of Compliance

(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

Note 4:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

Special Flight Permits

(e) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Issued in Renton, Washington, on April 23, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.