03-18419. Airworthiness Directives; Saab Model SAAB 2000 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 Saab Model SAAB 2000 series airplanes. This proposal would require an inspection to detect chafing or damage to the electrical wire harnesses in the left- and right-hand wing fuel tanks, applicable corrective action(s) if necessary, and installation of harnesses. For certain airplanes, this proposal also would require modifying the collector tank walls. This action is necessary to prevent chafing damage to the electrical wire harnesses in the left and right wing fuel tanks, which could cause misleading data and erroneous fuel pump cautions to be displayed to the flightcrew, and could result in electrical arcing with consequent increased potential for fire or explosion in the fuel tank. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by August 20, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-372-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. 2001-NM-372-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 Saab Aircraft AB, SAAB Aircraft Product Support, S-581.88, Linköping, Sweden. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Rosanne Ryburn, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 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 2001-NM-372-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. 2001-NM-372-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Luftfartsverket (LFV), which is the airworthiness authority for Sweden, notified the FAA that an unsafe condition may exist on certain Saab Model SAAB 2000 series airplanes. The LFV advises that an operator reported a damaged fuel tank harness, which resulted in an “R FUEL PUMP FAULT” caution. Inspection of the fuel tank wire harnesses revealed evidence of chafing due to the proximity of the wire harnesses to the openings in the metal collector tank walls. Chafing of the wire harness against the collector tank walls could expose the electric wiring in the harness to the collector tank wall. This condition, if not corrected, could cause misleading data and erroneous fuel pump cautions to be displayed to the flightcrew, and could result in electrical arcing with consequent increased potential for fire or explosion in the fuel tank.

Explanation of Relevant Service Information

Saab has issued Service Bulletin SAAB 2000-28-012, dated October 1, 2001, which describes procedures for a detailed inspection to detect chafing or damage to the electrical wire harnesses in the left- and right-hand wing fuel tanks; and applicable corrective action(s) if necessary. The corrective actions include:

• Adding and sealing a new piece of shrinkable tubing to repair a chafed/damaged area;
• Performing additional inspections; and
• Installing a new harness.

For certain airplanes, the service bulletin also describes procedures for modifying the collector tank walls. The modification includes:

• Increasing the cut out in the forward upper wall of the collector tanks;
• Removing all burrs and debris; breaking all sharp edges; applying alodine to the new edges; and
• Applying new part numbers to the doors.

In addition, the service bulletin describes procedures for installation of harnesses, which includes:

• Installing additional harness clamps;
• Cleaning the attaching surfaces;
• Installing new O-rings; and
• Applying primer and sealant.

Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. The LFV classified this service bulletin as mandatory and issued Swedish airworthiness directive 1-168, dated October 1, 2001, in order to assure the continued airworthiness of these airplanes in Sweden. The Swedish airworthiness directive contains a typographical error in that it references Saab Service Bulletin “SAAB 200-28-012” instead of Saab Service Bulletin “SAAB 2000-28-012.”

FAA's Conclusions

This airplane model is manufactured in Sweden and is type certificated for operation in the United States under the provisions of § 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the LFV has kept the FAA informed of the situation described above. The FAA has examined the findings of the LFV, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously, except as discussed below.

Differences Between Proposed Rule and Swedish Airworthiness Directive

The proposed AD would differ from the parallel Swedish airworthiness directive in that, if it is not possible to repair the chafed and/or opened area with a new piece of Viton shrinkable tubing, the proposed AD instructs operators to install a new electrical wire harness before further flight. The Swedish airworthiness directive instructs operators to return the damaged harness to Saab for repair. The FAA has notified the LFV of this difference in the proposed AD.

Cost Impact

The FAA estimates that 3 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 80 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $455 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $15,765, or $5,255 per airplane.

The cost impact figure discussed above is 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:

SAAB Aircraft AB: Docket 2001-NM-372-AD.

Applicability: Model SAAB 2000 series airplanes, serial numbers SAAB 2000-004 through ^063 inclusive, certificated in any category.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been 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 (f) 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 chafing damage to the electrical wire harnesses in the left- and right-hand wing fuel tanks, which could cause misleading data and erroneous fuel pump cautions to be displayed to the flightcrew, and could result in electrical arcing with consequent increased potential for fire or explosion in the fuel tank, accomplish the following:

Inspection

(a) For all airplanes: Within 18 months after the effective date of this AD, do a detailed inspection to detect chafing or damage to the electrical wire harnesses in the left- and right-hand wing fuel tanks, per the Accomplishment Instructions of Saab Service Bulletin SAAB 2000-28-012, dated October 1, 2001.

Note 2:

For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

Chafing or Damage: Corrective Actions

(b) If any chafing or damage is detected during the inspection required by paragraph (a) of this AD: Before further flight, do the applicable corrective action(s) (e.g., adding and sealing a new piece of Viton shrinkable tubing to repair a chafed/damaged area; and additional inspection) per paragraphs 2.C.(2)(b) and 2.C.(2)(c) of the Accomplishment Instructions of Saab Service Bulletin SAAB 2000-28-012, dated October 1, 2001, except as provided by paragraph (c) of this AD.

(c) For cases where it is not possible to repair the chafed and/or opened area with a new piece of Viton shrinkable tubing: Before further flight, install a new electrical wire harness per paragraph 2.E.(1) of the Accomplishment Instructions of Saab Service Bulletin SAAB 2000-28-012, dated October 1, 2001.

Modification (for Certain Airplanes)

(d) For airplanes having serial numbers SAAB 2000-007 through ^063 inclusive: Within 18 months after the effective date of this AD, modify the collector tank walls by accomplishing all the actions specified in paragraph 2.D. of the Accomplishment Instructions of Saab Service Bulletin SAAB 2000-28-012, dated October 1, 2001.

Installation

(e) For all airplanes: Within 18 months after the effective date of this AD, install new electrical wire harnesses by accomplishing all the actions specified in paragraph 2.E. of the Accomplishment Instructions of Saab Service Bulletin SAAB 2000-28-012, dated October 1, 2001.

Alternative Methods of Compliance

(f) 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, International Branch, ANM-116, Transport Airplane Directorate, FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.

Note 3:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

Special Flight Permits

(g) Special flight permits may be issued in accordance with sections §§ 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.

Note 4:

The subject of this AD is addressed in Swedish airworthiness directive 1-168, dated October 1, 2001.

Issued in Renton, Washington, on July 15, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.