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Airworthiness Directives; Fokker Model F.28 Mark 0100 Series Airplanes

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Information about this document as published in the Federal Register.

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Start Preamble

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Fokker Model F.28 Mark 0100 series airplanes. This action requires repetitive inspections of certain main landing gear (MLG) main fittings to detect forging defects, and rework of the main fittings if necessary. This action is necessary to detect forging defects of the MLG main fittings, which could lead to cracking and result in significant structural damage to the airplane and possible injury to the occupants.

DATES:

Effective December 20, 2001.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of December 20, 2001.

Comments for inclusion in the Rules Docket must be received on or before January 4, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-327-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-iarcomment@faa.gov. Comments sent via the Internet must contain “Docket No. 2001-NM-327-AD” in the subject line and need not be submitted in triplicate. Comments sent via fax or the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in this AD may be obtained from Fokker Services B.V., P.O. Box 231, 2150 AE Nieuw-Vennep, the Netherlands. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Tom Rodriguez, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1137; fax (425) 227-1149.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

The Civil Aviation Authority—The Netherlands (CAA-NL), which is the airworthiness authority for the Netherlands, notified the FAA that an unsafe condition may exist on certain Fokker Model F.28 Mark 0100 series airplanes. The CAA-NL advises that, upon touchdown, a main landing gear (MLG) main fitting failed, causing the lower part of the main fitting to break off, including the MLG sliding member, wheels, and brakes. Subsequent inspection revealed a crack, located 5 centimeters outboard from the inboard face of the upstop damper abutment, which measured 12 millimeters in length and 2.5 millimeters in depth. In that same area, an operator found 3 more MLG main fittings with an indication of an eddy current defect. In several other cases, the crack was determined to be due to a forging defect. This condition, if not corrected, could lead to cracking and result in significant structural damage to the airplane and possible injury to the occupants.

Explanation of Relevant Service Information

Messier-Dowty Limited has issued Messier-Dowty Service Bulletin No. F100-32-101, including Appendices A and B, dated October 25, 2001, which describes procedures for two inspections of the MLG fittings for cracking and rework of the MLG main fittings within certain areas.

Service Bulletin No. F100-32-101 refers to Messier-Dowty Service Bulletin No. F100-32-100, Revision 1, dated June 19, 2001, and Fokker Service Bulletin SBF100-32-131, dated October 25, 2001, as additional sources of service information for the inspections and rework actions.

The CAA-NL classified Messier-Dowty Service Bulletin No. F100-32-100 as mandatory and issued Dutch airworthiness directive BLA 2001-080, dated June 29, 2001, for a one-time eddy current inspection and rework actions to assure the continued airworthiness of these airplanes in the Netherlands.

FAA's Determination

Although the previously referenced Dutch airworthiness directive specifies Start Printed Page 63160a one-time eddy current inspection on MLG main fittings and rework actions per Messier-Dowty Service Bulletin No. F100-32-100, the FAA has determined that the initial and repetitive inspections required by paragraph (a) of this AD and the rework actions, if necessary, required by paragraph (b) of this AD must be made per Messier-Dowty Service Bulletin No. F100-32-101. This determination was made because the manufacturer informed the FAA that findings made after the issuance of Service Bulletin F100-32-100 indicate the need for additional eddy current inspections of the MLG main fittings. Findings also reveal that detection of closed forging folds might not be possible and that the forging folds would open when the main fittings are subjected to certain landing load levels. Because some detectable indications could be missed during the initial inspection, repetitive inspections are required to identify all detectable forging fold defects. To address these findings, Messier-Dowty has issued Service Bulletin No. F100-32-101 to specify additional inspections to safeguard the structural integrity of the MLG. As a result, the inspections required by paragraph (a) of this AD must be done per Service Bulletin No. F100-32-101 instead of Service Bulletin No. F100-032-100.

FAA's Conclusions

This airplane model is manufactured in the Netherlands and is 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 CAA-NL has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAA-NL, 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 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, this AD is being issued to detect forging defects of the MLG, and rework of the MLG main fittings if necessary. This AD requires initial and repetitive eddy current inspections of certain MLG main fittings to detect forging defects, and rework of the main fittings if necessary. This AD also would require that operators report all findings of the eddy current inspections to Fokker Services B.V. This AD requires accomplishment of the actions per Messier-Dowty Service Bulletin No. F100-32-101, as described previously, except as discussed below.

Differences Between Dutch Airworthiness Directive and This AD

Operators should note that, as described earlier, Dutch airworthiness directive BLA 2001-080 specifies only a one-time eddy current inspection of the MLG main fittings and rework actions per Messier-Dowty Service Bulletin No. F100-32-100, or a later revision approved by the CAA-NL. However, this AD requires an initial eddy current inspection and repetitive inspections, and rework of the MLG main fittings if necessary, per Messier-Dowty Service Bulletin No. F100-32-101. The CAA-NL has notified the FAA that it will issue a new Dutch airworthiness directive to mandate the inspections, and rework if necessary, specified by Service Bulletin No. F100-32-101. However, operators should note that this AD differs from Dutch airworthiness directive BLA 2001-080 in that it would require continuing the inspections until a final terminating action is identified.

Operators also should note that a later revision of a service bulletin may not be referenced in an AD because the use of the phrase “or a later revision” would violate Office of the Federal Register regulations regarding the approval of materials that are incorporated by reference.

Differences Between the Service Information and This AD

Operators should note the following differences between Service Bulletin No. F100-32-101 and this AD:

  • Although the referenced service bulletin specifies only two eddy current inspections, this AD requires an initial inspection and repetitive inspections until a final terminating action is identified. The FAA point outs that the exclusion of continued inspections after only two inspections relies on a damage tolerance approach. This approach leads the manufacturer to the conclusion that the crack growth is of a magnitude that would not lead to failure prior to overhaul. However, we do not agree with such a conclusion as there are a number of unknown variables associated with detecting and anticipating the effects of forging fold defects. For this reason, we have determined that requiring only two inspections would not adequately address the identified unsafe condition and that continued inspections until accomplishment of a terminating action are necessary to ensure the continued airworthiness of the fleet.
  • Although the referenced service bulletin specifies that the parts manufacturer may be contacted for disposition of certain discrepancies, this AD would require the repair of those conditions to be accomplished in accordance with a method approved by either the FAA, or CAA-NL (or its delegated agent). In light of the type of repair that would be required to address the identified unsafe condition, and in consonance with existing bilateral airworthiness agreements, the FAA has determined that, for this AD, a repair approved by either the FAA or CAA-NL (or its delegated agent) would be acceptable for compliance with this AD.
  • The referenced service bulletin specifies that, after accomplishing the actions specified in that service bulletin, rework of the MLG main fittings is to be accomplished per a new service bulletin, Messier-Dowty Service Bulletin F100-32-102. However, because the new service bulletin has not been issued yet, this AD cannot specify that service bulletin. The new service bulletin is expected to include procedures that would terminate the need for the inspections required by this AD.

Interim Action

This is considered to be interim action. The manufacturer has advised that it currently is developing rework procedures that will positively address the unsafe condition addressed by this AD. Once this procedure is developed, approved, and available, the FAA may consider additional rulemaking.

Determination of Rule's Effective Date

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All communications received on or before Start Printed Page 63161the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

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 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 rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NM-327-AD.” The postcard will be date stamped and returned to the commenter.

Regulatory Impact

The regulations adopted herein will 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 final rule does not have federalism implications under Executive Order 13132.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a “significant regulatory action” under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

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1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]
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2. Section 39.13 is amended by adding the following new airworthiness directive:

End Amendment Part

2001-24-10 Fokker Services B.V.: Amendment 39-12527. Docket 2001-NM-327-AD.

Applicability: Model F.28 Mark 0100 series airplanes, certificated in any category, equipped with Messier-Dowty main landing gear units having part numbers (P/N) 201072011, 201072012, 201072013, 201072014, 201072015, or 201072016, that include main fitting subassemblies having P/Ns 201072283, 201072284, or 201251258 (main fittings having P/Ns 201072383, 201072384, or 201072389).

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 (f) 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.

Note 2:

This AD references Messier-Dowty Service Bulletin No. F100-32-101, including Appendices A and B, dated October 25, 2001, which is not referenced in Dutch airworthiness directive BLA 2001-080, dated June 29, 2001. In addition, this AD specifies additional inspections that are beyond those included in the service bulletin. Where there are differences between the AD and the service information, the AD prevails.

To detect forging defects of the main landing gear (MLG), which could lead to cracking and result in significant structural damage to the airplane and possible injury to the occupants, accomplish the following:

Initial and Repetitive Inspections

(a) Before the accumulation of 1,000 total landings on a new MLG, or within 30 days after the effective date of this AD, whichever occurs later: Do an initial eddy current inspection on all MLG main fittings to detect forging defects per Messier-Dowty Service Bulletin No. F100-32-101, including Appendices A and B, dated October 25, 2001. After accomplishment of the initial inspection, repeat the inspection thereafter at intervals not to exceed 500 landings or 6 months, whichever occurs first, per the service bulletin.

Rework

(b) After any inspection required by paragraph (a) of this AD, before further flight, accomplish the applicable actions required by paragraph (b)(1) or (b)(2) of this AD.

(1) If any cracking is found within the limits specified in Messier-Dowty Service Bulletin No. F100-32-101, including Appendices A and B, dated October 25, 2001: Rework the MLG main fitting per the service bulletin.

(2) If any cracking is found that exceeds the limits specified in Messier-Dowty Service Bulletin No. F100-32-101, including Appendices A and B, dated October 25, 2001: Rework the MLG main fitting per a method approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; or the Civil Aviation Authority “ The Netherlands (CAA-NL) (or its delegated agent).

Exception to Service Information

(c) During any action required by this AD, if the service bulletin specifies to contact Messier-Dowty for an appropriate action: Before further flight, repair per a method approved by the Manager, International Branch, ANM-116; or the CAA-NL (or its delegated agent).

Reporting Requirement

(d) Within 7 days after accomplishing any inspection required by paragraph (a) of this AD: Submit a report of the inspection findings (positive and negative) to Fokker Services B.V, Technical Services Dept., P.O. Box 231, 2150 AE Nieuw-Vennep, the Netherlands, fax number 31 (0) 252 627211. The report must include MLG crack indication, part number, serial number, crack depth and length, and a description of any rework of the MLG main fittings accomplished. Information collection requirements contained in this AD have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.

Spares

(e) As of the effective date of this AD, no person shall install on any airplane, an MLG main fitting or main fitting subassembly having a part number specified in Paragraph 1.A of the “Effectivity” in Messier-Dowty Start Printed Page 63162Service Bulletin No. F100-32-101, including Appendices A and B, dated October 25, 2001, unless the MLG fitting has been inspected, and the rework actions accomplished if necessary, per the service bulletin.

Alternative Methods of Compliance

(f) 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 3:

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

(g) 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.

Incorporation by Reference

(h) Except for the actions required by paragraphs (b)(2) and (c) of this AD, the actions shall be done in accordance with Messier-Dowty Service Bulletin No. F100-32-101, including Appendices A and B, dated October 25, 2001. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Fokker Services B.V., P.O. Box 231, 2150 AE Nieuw-Vennep, the Netherlands. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Note 4:

The subject of this AD is addressed in Dutch airworthiness directive BLA 2001-080, dated June 29, 2001.

Effective Date

(i) This amendment becomes effective on December 20, 2001.

Start Signature

Issued in Renton, Washington, on November 26, 2001.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 01-30081 Filed 12-4-01; 8:45 am]

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