67 FR 55 pgs. 13108-13111 - Airworthiness Directives; Bombardier Model DHC-8-100, -200, and -300 Series Airplanes

Type: PRORULEVolume: 67Number: 55Pages: 13108 - 13111
Docket number: [Docket No. 2001-NM-69-AD]
FR document: [FR Doc. 02-6794 Filed 3-20-02; 8:45 am]
Agency: Transportation Department
Sub Agency: Federal Aviation Administration
Official PDF Version:  PDF Version

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-69-AD]

RIN 2120-AA64

Airworthiness Directives; Bombardier Model DHC-8-100, -200, 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 Bombardier Model DHC-8-100, -200, and "300 series airplanes. This proposal would require revision of the applicable maintenance program manual, repetitive inspections for corrosion or cracking of the hook roller shafts of the flap carriage, and eventual replacement of the hook roller shafts with new or serviceable hook roller shafts. This replacement would extend the interval for the repetitive inspections. This action is necessary to prevent cracking of the hook roller shafts of the flap carriage and consequent reduced structural integrity of the flap, which could result in jamming of the flap. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by April 22, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-69-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. 2001-NM-69-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 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, 10 Fifth Street, Third Floor, Valley Stream, New York.

FOR FURTHER INFORMATION CONTACT:

Dan Parrillo, Aerospace Engineer, Airframe and Propulsion Branch, ANE-172, FAA, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York 11581; telephone (516) 256-7505; fax (516) 568-2716.

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-69-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-69-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-8-100, -200, and -300 series airplanes. TCCA advises that corroded hook roller shafts have been found on the flap carriages of several in-service airplanes. During its investigation, the airplane manufacturer has identified discrepancies in the manufacturing process that may have resulted in inadequate corrosion protection on some hook roller shafts. This condition, if not corrected, could cause cracking of the hook roller shafts of the flap carriage and consequent reduced structural integrity of the flap, which could result to jamming of the flap.

Explanation of Relevant Service Information

Bombardier, Inc., has issued De Havilland Inc. Dash 8 Airworthiness Limitations List Temporary Revisions (TRs) AWL-75 and AWL-76 (for Model DHC-8-100 series airplanes), AWL 2-19 (for Model DHC-8-200 series airplanes), and AWL 3-83 (for Model DHC-8-300 series airplanes), all dated July 14, 2000. Those TRs specify new thresholds and repetitive intervals for existing structural inspections of the hook roller shafts of the flap carriage according to De Havilland Inc. Dash 8 Maintenance Program Manual PSM 1-8-7 (for Model DHC-8-100 series airplanes), PSM 1-82-7 (for Model DHC-8-200 series airplanes), or PSM 1-83-7 (for Model DHC-8-300 series airplanes), as applicable. TCCA classified these TRs as mandatory and issued Canadian airworthiness directive CF-1999-10R2, dated September 12, 2000, in order to assure the continued airworthiness of these airplanes in Canada. Canadian airworthiness directive CF-1999-10R2 also requires replacement of existing hook roller shafts with new or serviceable hook roller shafts.

FAA's Conclusions

This airplane model is manufactured in Canada 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, TCCA has kept the FAA informed of the situation described above. The FAA has examined the findings of the 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 revision of De Havilland Inc. Dash 8 Maintenance Program Manual PSM 1-8-7 (for Model DHC-8-100 series airplanes), PSM 1-82-7 (for Model DHC-8-200 series airplanes), or PSM 1-83-7 (for Model DHC-8-300 series airplanes), as applicable, repetitive detailed inspections for corrosion or cracking of the hook roller shafts of the flap carriage, and eventual replacement of the hook roller shafts with new or serviceable hook roller shafts. This replacement would extend the interval for the repetitive inspections. The inspections would be required to be accomplished according to the applicable De Havilland Inc. Dash 8 Maintenance Program Manual and at the compliance times specified in the TRs described previously. The replacement of the hook roller shafts would be required to be accomplished in accordance with certain sections of the applicable De Havilland Inc. Dash 8 Aircraft Maintenance Manual.

Differences Between the Proposed Rule and Service Information

The service information identifies the inspection described previously only as a "structural inspection." For clarity, this proposed AD refers to that structural inspection as a "detailed inspection." Note 2 of this proposed AD defines such an inspection.

Cost Impact

The FAA estimates that 183 airplanes of U.S. registry would be affected by this proposed AD.

It would take approximately 4 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 $43,920, or $240 per airplane, per inspection cycle.

It would take approximately 4 work hours per airplane to accomplish the proposed replacement, at an average labor rate of $60 per work hour. Required parts would cost approximately $460 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $128,100, or $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:

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket 2001-NM-69-AD.

Applicability: Model DHC-8-100, -200, and "300 series airplanes; serial numbers 3 through 555 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 (e) 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 cracking of the hook roller shafts of the flap carriage and consequent reduced structural integrity of the flap, which could result in jamming of the flap, accomplish the following:

Revision of Maintenance Program Manual

(a) Within 30 days after the effective date of this AD, accomplish paragraph (a)(1), (a)(2), or (a)(3) of this AD, as applicable.

(1) For Model DHC-8-100 series airplanes: Insert De Havilland Inc. Dash 8 Airworthiness Limitations List Temporary Revisions (TRs) AWL-75 and AWL-76, both dated July 14, 2000, into De Havilland Inc. Dash 8 Series 100 Maintenance Program Manual PSM 1-8-7.

(2) For Model DHC-8-200 series airplanes: Insert De Havilland Inc. Airworthiness Limitations List TR AWL 2-19, dated July 14, 2000, into De Havilland Inc. Dash 8 Series 200 Maintenance Program Manual PSM 1-82-7.

(3) For Model DHC-8-300 series airplanes: Insert De Havilland Inc. Airworthiness Limitations List TR AWL 3-83, dated July 14, 2000, into De Havilland Inc. Dash 8 Series 300 Maintenance Program Manual PSM 1-83-7.

Repetitive Inspections

(b) Do a detailed inspection for corrosion or cracking of the hook roller shafts of the flap carriage, at the times specified in paragraph (b)(1), (b)(2), or (b)(3) of this AD, as applicable, and according to the service information in paragraph (b)(1), (b)(2), or (b)(3) of this AD, as applicable.

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."

(1) For Model DHC-8-100 series airplanes: For Pre Mod 8Q101103 roller shafts having part number (P/N) 85750362-103 or 85750362-105, do the initial inspection at the compliance time specified in the "Threshold" column of the table in De Havilland Inc. Airworthiness Limitations List TRs AWL-75 and AWL-76, both dated July 14, 2000, or within 12 months after the effective date of this AD, whichever occurs later, according to De Havilland Inc. Dash 8 Series 100 Maintenance Program Manual PSM 1-8-7. Thereafter, repeat the inspection at the applicable interval specified in the "Initial Interval" column of the table in TR AWL-75 and AWL-76, until the airplane reaches the applicable threshold listed in the "Repeat Cut-In" column of the table in TR AWL-75 and AWL-76. Thereafter, repeat the inspections at the applicable interval listed in the "Repeat Interval" column of the table in TR AWL-75 and AWL-76, until paragraph (c) of this AD has been accomplished on all affected hook roller shafts. Where the TR specifies compliance intervals in "flights," for the purposes of this AD, "flights" means "flight cycles."

(2) For Model DHC-8-200 series airplanes: For Pre Mod 8Q101103 hook roller shafts having part number (P/N) 85750362-103 or 85750362-105, do the initial inspection at the compliance time specified in the "Threshold" column of the table in De Havilland Inc. Airworthiness Limitations List TR AWL 2-19, dated July 14, 2000, or within 12 months after the effective date of this AD, whichever occurs later, according to De Havilland Inc. Dash 8 Series 200 Maintenance Program Manual PSM 1-82-7. Thereafter, repeat the inspection at the applicable interval specified in the "Initial Interval" column of the table in TR AWL 2-19, until the airplane reaches the applicable threshold listed in the "Repeat Cut-In" column of the table in TR AWL 2-19. Thereafter, repeat the inspections at the applicable interval listed in the "Repeat Interval" column of the table in TR AWL 2-19, until paragraph (c) of this AD has been accomplished on all affected hook roller shafts. Where the TR specifies compliance intervals in "flights," for the purposes of this AD, "flights" means "flight cycles."

(3) For Model DHC-8-300 series airplanes: For Pre Mod 8Q101103 hook roller shafts having part number (P/N) 85750362-103 or 85750362-105, do the initial inspection at the compliance time specified in the "Threshold" column of the table in De Havilland Inc. Airworthiness Limitations List TR AWL 3-83, or within 12 months after the effective date of this AD, whichever occurs later, according to De Havilland Inc. Dash 8 Series 300 Maintenance Program Manual PSM 1-83-7. Thereafter, repeat the inspection at the applicable interval specified in the "Initial Interval" column of the table in TR AWL 3-83, until the airplane reaches the applicable threshold listed in the "Repeat Cut-In" column of the table in TR AWL 3-83. Thereafter, repeat the inspections at the applicable interval listed in the "Repeat Interval" column of the table in TR AWL 3-83 until paragraph (c) of this AD has been accomplished on all affected hook roller shafts. Where the TR specifies compliance intervals in "flights," for the purposes of this AD, "flights" means "flight cycles."

Replacement

(c) At the applicable time specified in paragraph (c)(1) or (c)(2) of this AD, replace hook roller shafts having P/N 85750362-103 or 85750362-105 with new or serviceable hook roller shafts having P/N 85750362-107, according to Sections 57-50-44 and 57-50-53 of the De Havilland Inc. Dash 8 Aircraft Maintenance Manual, as applicable. Replacement of all hook roller shafts, P/N 85750362-103 or 85750362-105, with new hook roller shafts, P/N 85750362-107, ends the repetitive inspections at the intervals required by paragraph (a) of this AD.

(1) For hook roller shafts on which any corrosion or crack is found during any inspection per paragraph (b) of this AD: Do the replacement before further flight.

(2) For uncracked or uncorroded hook roller shafts: Do the replacement within 20,000 flight cycles or 5 years after the effective date of this AD, whichever is first.

Post-Replacement Inspections

(d) Following the replacement of hook roller shafts according to paragraph (c) of this AD, do the Structural Inspection Program for the hook roller shafts of the flap carriage, as specified in paragraph (d)(1), (d)(2), or (d)(3) of this AD, as applicable.

(1) For Model DHC-8-100 series airplanes: Using the criteria for Mod 8Q101103 hook roller shafts having P/N 85750362-107, do the initial inspection at the compliance time specified in the "Threshold" column of the table in De Havilland Inc. Airworthiness Limitations List TR AWL-75 and AWL "76, both dated July 14, 2000, according to De Havilland Inc. Dash 8 Series 100 Maintenance Program Manual PSM 1-8-7. Thereafter, repeat the inspection at the applicable interval specified in the "Initial Interval" column of the table in TRs AWL-75 and AWL -76, until the airplane reaches the applicable threshold listed in the "Repeat Cut-In" column of the table in TRs AWL-75 and AWL-76. Thereafter, repeat the inspections at the applicable interval listed in the "Repeat Interval" column of the table in TRs AWL-75 and AWL-76. Where the TR specifies compliance intervals in "flights," for the purposes of this AD, "flights" means "flight cycles."

(2) For Model DHC-8-200 series airplanes: Using the criteria for Mod 8Q101103 hook roller shafts having P/N 85750362-107, do the initial inspection at the compliance time specified in the "Threshold" column of the table in De Havilland Inc. Airworthiness Limitations List TR AWL 2-19, dated July 14, 2000, according to De Havilland Inc. Dash 8 Series 200 Maintenance Program Manual PSM 1-82-7. Thereafter, repeat the inspection at the applicable interval specified in the "Initial Interval" column of the table in TR AWL 2-19, until the airplane reaches the applicable threshold listed in the "Repeat Cut-In" column of the table in TR AWL 2-19. Thereafter, repeat the inspections at the applicable interval listed in the "Repeat Interval" column of the table in TR AWL 2-19. Where the TR specifies compliance intervals in "flights," for the purposes of this AD, "flights" means "flight cycles."

(3) For Model DHC-8-300 series airplanes: Using the criteria for Mod 8Q101103 hook roller shafts having P/N 85750362-107, do the initial inspection at the compliance time specified in the "Threshold" column of the table in De Havilland Inc. Airworthiness Limitations List TR AWL 3-83, according to De Havilland Inc. Dash 8 Series 300 Maintenance Program Manual PSM 1-83-7. Thereafter, repeat the inspection at the applicable interval specified in the "Initial Interval" column of the table in TR AWL 3-83, until the airplane reaches the applicable threshold listed in the "Repeat Cut-In" column of the table in TR AWL 3-83. Thereafter, repeat the inspections at the applicable interval listed in the "Repeat Interval" column of the table in TR AWL 3-83. Where the TR specifies compliance intervals in "flights," for the purposes of this AD, "flights" means "flight cycles."

Alternative Methods of Compliance

(e) 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, New York Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO.

Note 3:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO.

Special Flight Permits

(f) Special flight permits may be issued in accordance with §§ 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 Canadian airworthiness directive CF-1999-10R2, dated September 12, 2000.

Issued in Renton, Washington, on March 14, 2002.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 02-6794 Filed 3-20-02; 8:45 am]

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