04-5943. Airworthiness Directives; Fokker Model F.28 Mark 0070 and 0100 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Fokker Model F.28 Mark 0100 series airplanes, that currently 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 would require either replacement of each MLG with a MLG that has main fittings that have been inspected and reworked, or various one-time inspections of the main fittings and rework if necessary. Either of these actions would constitute terminating action for the repetitive inspections. This action would also revise the applicability by adding airplanes. The actions specified by the proposed AD are intended 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. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by April 16, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-162-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 [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-162-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 Fokker Services B.V., PO 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.

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 [phone]; fax [phone].

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 2003-NM-162-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. 2003-NM-162-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On November 26, 2001, the FAA issued AD 2001-24-10, amendment 39-12527 (66 FR 63159, December 5, 2001), applicable to certain Fokker Model F.28 Mark 0100 series airplanes. That AD requires repetitive inspections of certain main landing gear (MLG) main fittings to detect forging defects, and rework of the main fittings if necessary. The requirements of that AD are intended 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.

Actions Since Issuance of Previous AD

Since the issuance of that AD, the airplane manufacturer has advised us that additional airplanes (Model F.28 Mark 0070 series airplanes) may be equipped with the same Messier-Dowty MLG units that are subject to the identified unsafe condition.

Also, the preamble to AD 2001-24-10 specified that we considered the requirements “interim action” and that the manufacturer was developing rework procedures to address the unsafe condition. The manufacturer now has developed such rework procedures, and we have determined that further rulemaking is indeed necessary; this proposed AD follows from that determination.

Explanation of Relevant Service Information

Fokker Services B.V. has issued Service Bulletin SBF100-32-134, dated March 24, 2003. Part 1 of the service bulletin describes procedures for removing the MLGs from the airplane; doing a detailed inspection of the MLG pintle pins, side stay attachment pins, and MLG retract actuator attachment bolts; and installing MLGs with main fittings that were reworked.

Part 2 of Fokker Services B.V. Service Bulletin SBF100-32-134 describes procedures for doing eddy current and etch penetrant inspections on MLG main fittings and identifying MLGs that have been inspected. For discrepancies (e.g., cracking or detected flaws of up to 50% of the calibration amplitude of the eddy current flaw detector) found during the inspections, Part 2 also includes procedures for reworking certain discrepancies and contacting the part manufacturer for discrepancies that are outside the permitted rework areas, or that cannot be removed within the limits specified in the service bulletin.

Both Parts 1 and 2 of Service Bulletin SBF100-32-134 refer to Messier-Dowty Ltd. Service Bulletin F100-32-102, including Appendices A, B, and C, dated February 24, 2003, as an additional source of information for reworking the main fittings of the MLGs, doing the eddy current and etch penetrant inspections, and identifying MLGs that have been inspected.

The Civil Aviation Authority—The Netherlands (CAA-NL), which is the airworthiness authority for the Netherlands, classified Fokker Service Bulletin SBF100-32-134 and Messier-Dowty Ltd. Service Bulletin F100-32-102 as mandatory and issued Dutch airworthiness directive 2003-040, dated March 31, 2003, to ensure the continued airworthiness of these airplanes in the Netherlands.

FAA's Conclusions

These airplane models are manufactured in the Netherlands 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 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 Proposed AD

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 supersede AD 2001-24-10 to continue to require repetitive inspections of certain MLG main fittings to detect forging defects, and rework of the main fittings if necessary. The proposed AD also would require either replacement of the MLG with a MLG that has main fittings that have been inspected and reworked, or various one-time inspections of the main fittings, and rework if necessary. Either of these actions would constitute terminating action for the repetitive inspections. This action would also revise the applicability by adding airplanes. The actions would be required to be accomplished in accordance with the service bulletins described previously, except as discussed below.

Differences Among the Proposed AD, Service Bulletins, and Dutch Airworthiness Directive

The Dutch airworthiness directive and Fokker Service Bulletin SBF100-32-134 recommend that the actions which terminate the repetitive inspections be accomplished prior to or during the next scheduled overhaul of the affected MLG main fitting. Because overhaul schedules vary among operators, this proposed AD would require accomplishment of the terminating actions prior to the accumulation of 16,000 total landings on a new MLG. This compliance time represents the life limit for the MLG main fitting.

Operators should note that, although the Dutch airworthiness directive describes procedures for reporting inspection results to Messier-Dowty and Fokker B.V. Services, this proposed AD would not require those actions.

Although Fokker Service Bulletin SBF100-32-134 and Messier-Dowty Ltd. Service Bulletin F100-32-102 both specify that the parts manufacturer may be contacted for disposition of certain discrepancies, this proposed 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.

Change to Requirements of Existing AD

AD 2001-24-10 included a reporting requirement to enable the manufacturer to obtain better insight into the nature, cause, and extent of the cracking, and to develop final action to address the unsafe condition. This proposed AD includes such final action; therefore, the reporting requirement is not included in the requirements of this proposed AD.

Changes to 14 CFR Part 39/Effect on the AD

On July 10, 2002, the FAA issued a new version of 14 CFR Part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance (AMOC). Because we have now included this material in part 39, only the office authorized to approve AMOCs is identified in each individual AD. Therefore, paragraph (g) and Note 1 of AD 2001-24-10 are not included in this proposed AD.

Cost Impact

There are approximately 70 airplanes of U.S. registry that would be affected by this proposed AD.

The repetitive inspections currently required by AD 2001-24-10 take approximately 2 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $9,100, or $130 per airplane, per inspection cycle.

Should an operator rework a MLG per Part 1 of Fokker Service Bulletin SBF100-32-134, it would take approximately 44 work hours per airplane at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed modification is estimated to be $2,860 per airplane.

Should an operator do the inspections specified in Messier-Dowty Service Bulletin F100-32-102, it would take approximately 2 work hours per airplane at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed inspections is estimated to be $130 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or 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.

§ 39.13

[Amended]

2. Section 39.13 is amended by removing amendment 39-12527 (66 FR 63159, December 5, 2001), and by adding a new airworthiness directive (AD), to read as follows:

Fokker Services B.V.: Docket 2003-NM-162-AD. Supersedes AD 2001-24-10, Amendment 39-12527.

Applicability: Model F.28 Mark 0070 and 0100 series airplanes, certificated in any category, equipped with a Messier-Dowty main landing gear (MLG) unit having a part number (P/N) with a main fitting sub-assembly, as listed in Table 1 of this AD.

Table 1.—Applicability

P/N—	Which includes a main fitting sub-assembly P/N—
201072011	201072283, 201072284, or 201251258 (main fitting P/N 201072383, 201072384, or 201072389)
201072012	201072283, 201072284, or 201251258 (main fitting P/N 201072383, 201072384, or 201072389)
201072013	201072283, 201072284, or 201251258 (main fitting P/N 201072383, 201072384, or 201072389)
201072014	201072283, 201072284, or 201251258 (main fitting P/N 201072383, 201072384, or 201072389)
201072015	201072283, 201072284, or 201251258 (main fitting P/N 201072383, 201072384, or 201072389)
201072016	201072283, 201072284, or 201251258 (main fitting P/N 201072383, 201072384, or 201072389)

Compliance: Required as indicated, unless accomplished previously.

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, accomplish the following:

Restatement of the Requirements of AD 2001-24-10: Initial and Repetitive Inspections

(a) For Fokker Model F.28 Mark 0100 series airplanes: Before the accumulation of 1,000 total landings on a new MLG, or within 30 days after December 20, 2001 (the effective date of AD 2001-24-10, amendment 39-12527), whichever occurs later, do an initial eddy current inspection on all MLG main fittings to detect forging defects, per Messier-Dowty Ltd. Service Bulletin F100-32-101, including Appendices A and B, dated October 25, 2001. After accomplishment of the initial inspection, repeat the eddy current inspection thereafter at intervals not to exceed 500 landings or 6 months, whichever occurs first, per the service bulletin. Accomplishment of the actions required by paragraph (f) of this AD terminates the repetitive inspections. Although this service bulletin specifies to submit certain information to the part manufacturer, this AD does not include such a requirement.

Rework

(b) For Fokker Model F.28 Mark 0100 series airplanes: 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 Ltd. Service Bulletin 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 Ltd. Service Bulletin 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 Ltd. 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).

New Actions Required by This AD

Initial and Repetitive Inspections

(d) For Fokker Model F.28 Mark 0070 series airplanes: 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 Ltd. Service Bulletin 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. Accomplishment of the actions required by paragraph (f) of this AD terminates the repetitive inspections.

Rework

(e) For Fokker Model F.28 Mark 0070 series airplanes: After any inspection required by paragraph (d) of this AD, before further flight, accomplish the applicable actions required by paragraph (e)(1) or (e)(2) of this AD.

(1) If any cracking is found within the limits specified in Messier-Dowty Ltd. Service Bulletin 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 Ltd. Service Bulletin 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; or the CAA-NL (or its delegated agent).

Terminating Actions

(f) For all airplanes: Before the accumulation of 16,000 total landings on a new MLG, do the actions in paragraph (f)(1) or (f)(2) of this AD. Accomplishment of paragraph (f)(1) or (f)(2) of this AD constitutes terminating action for the repetitive inspections required by paragraphs (a) and (d) of this AD.

(1) Replace the main fitting of the MLG with a main fitting that has had a detailed inspection to detect forging defects and has been reworked, per paragraph 2.B., Part 1, of the Accomplishment Instructions of Fokker Service Bulletin SBF100-32-134, dated March 24, 2003. Any discrepancy found during the detailed inspection must be repaired before further flight per the Fokker 100 Aircraft Maintenance Manual and Messier-Dowty Ltd. Component Maintenance Manual 32-11-04; or per a method approved by the Manager, International Branch, ANM-116, or the CAA-NL (or its delegated agent).

Note 1:

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.”

Note 2:

Fokker Service Bulletin SBF100-32-134, dated March 24, 2003, references Messier-Dowty Ltd. Service Bulletin F100-32-102, including Appendices A, B, and C, dated February 24, 2003, as an additional source of service information for reworking the main fitting of each MLG.

(2) Do eddy current and etch penetrant inspections, as applicable, to detect forging defects; and rework the main fitting of each MLG, as applicable; by accomplishing all of the actions in paragraph 3.C. of the Accomplishment Instructions of Messier-Dowty Ltd. Service Bulletin F100-32-102, including Appendices A, B, and C, dated February 24, 2003. Do all of the actions per the service bulletin. Any rework must be done before further flight.

Parts Installation

(g) As of the effective date of this AD, no person may install a MLG, MLG main fitting sub-assembly, or MLG main fitting having a P/N listed in Messier-Dowty Ltd. Service Bulletin F100-32-102, including Appendices A, B, and C, dated February 24, 2003, on any airplane unless the part has been inspected and reworked, as applicable, per that service bulletin.

Alternative Methods of Compliance

(h) In accordance with 14 CFR 39.19, the Manager, International Branch, ANM-116, is authorized to approve alternative methods of compliance for this AD.

Note 3:

The subject of this AD is addressed in Dutch airworthiness directive 2003-040, dated March 31, 2003.

Issued in Renton, Washington, on March 5, 2004.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.