01-20811. Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B 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 SF340A and SAAB 340B series airplanes. This proposal would require a one-time review of records to determine whether an airplane has been repainted since its delivery from the factory; and a one-time inspection to detect damage associated with improper preparation for the repainting, and corrective action, if necessary. This action is prompted by mandatory continuing airworthiness information from a foreign civil airworthiness authority. This action is necessary to detect and correct damage to the aluminum skin of the airplane, which could result in a weakening of the structure of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by September 17, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket Number 2001-NM-91-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 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-91-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:

Todd Thompson, 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-91-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 Number 2001-NM-91-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 Saab Model SAAB SF340A and SAAB 340B series airplanes. The LFV advises that, on a number of airplanes that were repainted after being delivered from the factory, the preparation for such repainting was performed using unapproved methods, including sanding the aluminum skin down to bare metal. These unapproved methods may have damaged the skin by removing its anodized and primed protective coat, causing pitting corrosion, or reducing the thickness of the skin to less than the minimum allowable. This condition, if not corrected, could result in damage to the aluminum skin of the airplane, with consequent weakening of the structure of the airplane.

Explanation of Relevant Service Information

Saab has issued Service Bulletin 340-51-020, Revision 01, dated May 16, 2001, which describes procedures for a one-time inspection of repainted airplanes for damage caused by use of unapproved methods during preparation for repainting. Such damage includes removal of the skin's protective coating of bonding primer, pitting corrosion of the skin, or reduction of the thickness of the skin to less than the minimum allowable. The service bulletin also describes corrective action to be taken, if it is found that an unapproved method was used. The LFV classified this service bulletin as mandatory and issued Swedish airworthiness directive 1-161 R1, dated March 5, 2001, in order to assure the continued airworthiness of these airplanes in Sweden.

Differences Between Proposed Rule and Service Bulletin

Operators should note that, although the service bulletin specifies that the manufacturer may be contacted for disposition of certain repair conditions that are detected during the inspection, this proposed rule would require the repair of those conditions to be accomplished by a method approved by the FAA or the LFV (or its designated agent).

FAA's Conclusions

These airplane models are manufactured in Sweden and are type certificated for operation in the United States under the provisions of section 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 rule would require accomplishment of the actions specified in the service bulletin described previously, except as discussed below.

Cost Impact

The FAA estimates that 288 airplanes of U.S. registry would be affected by this proposed rule.

It would take 1 work hour per airplane to accomplish the proposed review of records, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the proposed review of records on U.S. operators is estimated to be $17,280, or $60 per airplane.

For those airplanes which have been repainted, it would take 20 to 45 work hours per airplane to accomplish the proposed inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the proposed inspection on U.S. operators is estimated to be $1,200 to $2,700 per airplane.

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:

SAAB AIRCRAFT AB: Docket 2001-NM-91-AD

Applicability: Model SAAB SF340A series airplanes having serial numbers -004 through -159 inclusive, and SAAB 340B series airplanes having serial numbers -160 through -459 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 (c) 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 detect and correct damage to the aluminum skin of the airplane, which could result in a weakening of the structure of the airplane, accomplish the following:

Review of Records

(a) Within 200 flight hours or 1 year after the effective date of this AD, whichever occurs first: Perform a review of records to determine whether an airplane subject to this AD has been repainted since its delivery from the factory. If the airplane has not been repainted, no further action is needed.

Inspection and Corrective Action

(b) If an airplane has been repainted since its delivery from the factory: Within 200 flight hours or 1 year after the effective date of this AD, whichever occurs first, perform chemical stripping of local areas of the skin and inspection to detect damage to (or removal of) the protective coat of bonding primer, in accordance with Saab Service Bulletin 340-51-020, Revision 01, dated May 16, 2001.

(1) If no damage to the protective coat of bonding primer is detected: Prior to further flight, repaint the stripped areas, in accordance with the service bulletin.

(2) If damage to (or removal of) the protective coat of bonding primer is detected: Prior to further flight, perform additional chemical stripping and inspection of the skin for pitting corrosion, in accordance with the service bulletin.

(i) If pitting corrosion is detected: Prior to further flight, perform corrective action in a manner approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, or the Luftfartsverket (or its designated agent).

(ii) If no pitting corrosion is detected: Prior to further flight, measure the thickness of the skin of the airplane, in accordance with the service bulletin.

(A) If a reduction in skin thickness is detected: Prior to further flight, perform corrective action in a manner approved by the Manager, International Branch, ANM-116, or the Luftfartsverket (or its designated agent).

(B) If no reduction in skin thickness is detected: Prior to further flight, check records to determine whether the airplane was repainted using an approved paint system.

(1) If the airplane was repainted using an approved paint system: Prior to further flight, repaint the stripped areas of the airplane, in accordance with the service bulletin.

(2) If the airplane was painted using an unapproved paint system: Prior to further flight, chemically strip the entire airplane and repaint it, in accordance with the service bulletin.

Alternative Methods of Compliance

(c) 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. 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 2:

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

(d) 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 3:

The subject of this AD is addressed in Swedish airworthiness directive 1-161R1, dated May 5, 2001.

Issued in Renton, Washington, on August 13, 2001.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.