Airworthiness Directives; deHavilland Inc. Models DHC-2 Mk. I and DHC-2 Mk. II Airplanes and Bombardier Inc. Model (Otter) DHC-3 Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all deHavilland Inc. Models DHC-2 Mk. I and DHC-2 Mk. II airplanes and for all Bombardier Inc. Model (Otter) DHC-3 airplanes powered by radial engines. This proposed AD would require you to visually inspect the firewall ignition plugs and receptacles for proper lockwire security and replace or modify as appropriate. This proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Canada. We are issuing this proposed AD to prevent loss of ignition systems during flight caused by improper lockwire security, which could result in engine failure. This failure could lead to a forced landing of the airplane.

DATES:

We must receive any comments on this proposed AD by May 7, 2004.

ADDRESSES:

Use one of the following to submit comments on this proposed AD:

• By mail: FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2004-CE-02-AD, 901 Locust, Room 506, Kansas City, Missouri 64106.
• By fax: (816) 329-3771.
• By e-mail: 9-ACE-7-Docket@faa.gov. Comments sent electronically must contain “Docket No. 2004-CE-02-AD” in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Word 97 for Windows or ASCII.

You may get the service information identified in this proposed AD from Bombardier Aerospace Regional Aircraft, Garratt Boulevard, Downsview, Ontario, Canada M3K 1Y5; facsimile: (416) 375-4538.

You may view the AD docket at FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2004-CE-02-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. Office hours are 8 a.m. to 4 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Sarbhpreet Singh Sawhney, Aerospace Engineer, New York Aircraft Certification Office (ACO), FAA, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone: (516) 228-7340; facsimile: (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited

How do I comment on this proposed AD? We invite you to submit any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2004-CE-02-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it. We will date-stamp your postcard and mail it back to you.

Are there any specific portions of this proposed AD I should pay attention to? We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. If you contact us through a nonwritten communication and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend this proposed AD in light of those comments and contacts.

Discussion

What events have caused this proposed AD? Transport Canada, which is the airworthiness authority for Canada, recently notified FAA that an unsafe condition may exist on all deHavilland DHC-2 Mk. I and DHC-2 Mk. II airplanes and all Bombardier (Otter) DHC-3 airplanes powered by radial engines. Transport Canada reports that a DHC-3 airplane lost both ignition systems during flight.

The lockwire hole in the ignition connector plug on the firewall broke and the plug vibrated loose. Both magnetos then grounded through a spring-loaded center pin in the plug (a maintenance safety feature).

The DHC-2 Mk. I and DHC-2 Mk. II airplanes have a similar ignition system.

What are the consequences if the condition is not corrected? If not detected and corrected, failure of the lockwire hole could result in engine failure. This failure could lead to a forced landing of the airplane.

Is there service information that applies to this subject? Bombardier has issued deHavilland Beaver Alert Service Bulletin Number A2/53, Revision A, dated August 30, 2001; and deHavilland Otter Alert Service Bulletin Number A3/53, Revision A, dated August 30, 2001.

What are the provisions of this service information? These service bulletins include procedures for:

• Inspecting the ignition plugs and receptacles on the fore and aft side of the firewall for security;
• Replacing any plugs or receptacles with damaged lockwire holes; and
• Replacing any damaged lockwire.

What action did Transport Canada take? Transport Canada classified these service bulletin as mandatory and issued Canadian AD Number CF-2001-36, dated October 31, 2001, and Canadian AD Number CF-2001-37, dated October 31, 2001, to ensure the continued airworthiness of these airplanes in Canada.

Did Transport Canada inform the United States under the bilateral airworthiness agreement? These deHavilland DHC-2 Mk. I and DHC-2 Mk. II airplanes, and Bombardier (Otter) DHC-3 airplanes are manufactured in Canada 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.

Under this bilateral airworthiness agreement, Transport Canada has kept us informed of the situation described above.

FAA's Determination and Requirements of This Proposed AD

What has FAA decided? We have examined Transport Canada's findings, 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.

Since the unsafe condition described previously is likely to exist or develop on other deHavilland DHC-2 Mk. I and DHC-2 Mk. II airplanes, and Bombardier (Otter) DHC-3 airplanes powered by radial engines of the same type design that are registered in the United States, we are proposing AD action to prevent loss of ignition systems during flight caused by improper lockwire security, which could result in engine failure. This failure could lead to a forced landing of the airplane.

What would this proposed AD require? This proposed AD would require you to incorporate the actions in the previously-referenced service bulletin.

How does the revision to 14 CFR part 39 affect this proposed AD? On July 10, 2002, we published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.

Costs of Compliance

How many airplanes would this proposed AD impact? We estimate that this proposed AD affects 242 airplanes in the U.S. registry.

What would be the cost impact of this proposed AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish this proposed inspection:

We estimate the following costs to accomplish any necessary replacements that would be required based on the results of this proposed inspection. We have no way of determining the number of airplanes that may need these replacements:

Regulatory Findings

Would this proposed AD impact various entities? 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.

Would this proposed AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this proposed AD:

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 summary of the costs to comply with this proposed AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2004-CE-02-AD” in your request.

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 Federal Aviation Administration proposes to amend 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.