Airworthiness Directives; Dornier Model 328-100 and -300 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 Dornier Model 328-100 and -300 series airplanes. This proposal would require inspection of the metal oxide varistor (MOV) modules and transient absorption zener (TAZ) diodes to determine if those parts are outside of tolerance limits, and replacement of MOV modules and TAZ diodes with new parts, if necessary. This action is necessary to prevent the failure of critical ice protection systems following a lightning strike, which could result in reduced controllability and degraded performance of the airplane in the event of an encounter with icing conditions. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by March 29, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-310-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 (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-310-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 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from AvCraft Aerospace GmbH, P.O. Box 1103, D-82230 Wessling, Germany. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Thomas Groves, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1503; fax (425) 227-1149.

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-310-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-310-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, notified the FAA that an unsafe condition may exist on certain Dornier Model 328-100 and -300 series airplanes. The metal oxide varistor (MOV) modules protect the propeller deice system from the effects of lightning strikes. The transient absorption zener (TAZ) diodes protect other ice protection functions from the effects of lightning strikes. The LBA advises that 37% of the inspected fleet has been found with TAZ diodes and MOV modules that are out of tolerance. Further investigation revealed that the airplane maintenance manual (AMM) does not include a check of this equipment following a lightning strike. The out of tolerance condition, if not corrected, could result in the failure of critical ice protection systems following a lightning strike, which could result in reduced controllability and degraded performance of the airplane in the event of an encounter with icing conditions.

Explanation of Relevant Service Information

Dornier has issued Service Bulletins SB-328-30-417, dated January 24, 2002 (for Model 328-100 series airplanes), and SB-328J-30-150, dated January 24, 2002 (for Model 328-300 series airplanes). The service bulletins describe procedures for inspection of the MOV modules and TAZ diodes to determine if those parts are out of tolerance, and replacement of any MOV module or TAZ diode with a new part if found out of tolerance. Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition. The LBA classified these service bulletins as mandatory and issued German airworthiness directives 2002-262 and 2002-263, both dated September 19, 2002, to assure the continued airworthiness of these airplanes in Germany.

FAA's Conclusions

These airplane models are manufactured in Germany 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 LBA has kept the FAA informed of the situation described above. The FAA has examined the findings of the LBA, 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 bulletins described previously, except as discussed below.

Difference Between Proposed Rule and Referenced Service Bulletin

Operators should note that, although the Accomplishment Instructions of the referenced service bulletins describe procedures for submitting a test report, this proposed AD would not require that action. The FAA does not need this information from operators.

Cost Impact

The FAA estimates that 53 Model 328-100 series airplanes and 48 Model 328-300 series airplanes of U.S. registry would be affected by this proposed AD.

For Model 328-100 airplanes, it would take approximately 6 work hours per airplane to accomplish the proposed inspection, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators of these airplanes is estimated to be $20,670, or $390 per airplane.

For Model 328-300 airplanes, it would take approximately 3 work hours per airplane to accomplish the proposed inspection, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators of these airplanes is estimated to be $9,360, or $195 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.