Airworthiness Directives; Bombardier Model DHC-8-400, -401, and -402 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 Bombardier Model DHC-8-400, -401, and -402 airplanes. This proposal would require an inspection to determine the serial number of the spoiler lift dump valves installed on the inboard and outboard spoilers, and replacement of certain spoiler lift dump valves. This proposal also would provide for revising the airplane flight manual to include performance penalties, which would allow the replacement of affected spoiler lift dump valves to be deferred. This action is necessary to prevent failure of the ground spoilers to deploy on the ground, which could result in overrunning the end of the runway in the event of a rejected takeoff. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by April 5, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-132-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-132-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 Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Westbury, New York.

FOR FURTHER INFORMATION CONTACT:

Ezra Sasson, Aerospace Engineer, Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Westbury, New York 11590; telephone (516) 228-7320; fax (516) 794-5531.

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-132-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-132-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on certain Bombardier Model DHC-8-400, -401, and -402 airplanes. TCCA advises that, during manufacturing, a venting slot was omitted on one batch of the solenoid armatures that operate the spoiler lift dump valves. Absence of this venting slot could create a pressure differential that prevents the solenoid armature from shuttling and supplying hydraulic pressure to the actuator of the spoiler lift dump valves. This condition, if not corrected, could cause failure of the ground spoilers to deploy on the ground, which could result in overrunning the end of the runway in the event of a rejected takeoff.

Explanation of Relevant Service Information

Bombardier has issued de Havilland Service Bulletin 84-27-12, Revision “A,” dated December 12, 2001, which describes procedures for an inspection to determine the serial number of the spoiler lift dump valves installed on the inboard and outboard spoilers. For spoiler lift dump valves with serial numbers within a certain range, the service bulletin describes procedures for replacing the existing spoiler lift dump valve with one that it is outside the affected range of serial numbers or one that has been modified. Service Bulletin 84-27-12 refers to Parker Service Bulletin 395800-27-229, dated September 11, 2001, as an additional source of service information for replacing the spoiler dump valves. The Parker service bulletin is included within the de Havilland service bulletin.

Accomplishment of the actions specified in the de Havilland service bulletin is intended to adequately address the identified unsafe condition. TCCA classified the de Havilland service bulletin as mandatory and issued Canadian airworthiness directive CF-2001-44, dated December 3, 2001, to ensure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

These airplane models 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. Pursuant to this bilateral airworthiness agreement, TCCA has kept us informed of the situation described above. We have examined the findings of TCCA, 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 de Havilland service bulletin described previously, except as discussed below. This proposed AD also provides for revising the airplane flight manual (AFM) to include performance penalties, which would allow the replacement of affected spoiler lift dump valves to be deferred for a certain length of time. Once the spoiler lift dump valves have been replaced, these performance penalties may be removed from the AFM.

Difference Between Service Information and Proposed AD

Although the Parker service bulletin included within the de Havilland service bulletin specifies to return affected parts to the manufacturer, this proposed AD would not include such a requirement.

Cost Impact

We estimate that 10 airplanes of U.S. registry would be affected by this proposed AD.

It would take approximately 1 work hour per airplane to accomplish the proposed inspection to determine the serial number of the spoiler lift dump valves, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of this proposed inspection on U.S. operators is estimated to be $650, or $65 per airplane.

For airplanes equipped with spoiler lift dump valves in the affected serial number range, it would take approximately 2 work hours per airplane to accomplish the proposed replacement, at an average labor rate of $65 per work hour. Required parts would be provided by the parts manufacturer at no charge. Based on these figures, the cost impact of this proposed replacement is estimated to be $130 per airplane.

Should an operator elect to accomplish the AFM revision that allows deferral of the replacement, it would take approximately 1 work hour per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of this AFM revision, if accomplished, would be $65 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 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.