AD 95-12827

[Federal Register Volume 60, Number 101 (Thursday, May 25, 1995)] [Proposed Rules] [Pages 27704-27705] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 95-12827]

======================================================================== Proposed Rules Federal Register ________________________________________________________________________ This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. ========================================================================

Federal Register / Vol. 60, No. 101 / Thursday, May 25, 1995 / Proposed Rules

[[Page 27704]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-38-AD]

Airworthiness Directives; Fokker Model F28 Mark 0100 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Fokker Model F28 Mark 0100 series airplanes. This proposal would require replacement of the return filter diaphragm assemblies on hydraulic systems 1 and 2 with modified filter units having new diaphragms. This proposal is prompted by a report of insufficient running clearance of the brake units due to overpressure in the hydraulic return system; this condition could lead to brake overheating. The actions specified by the proposed AD are intended to prevent overpressure of the hydraulic return system, which could result in reduced braking performance and/or blown tires due to brake overheating.

DATES: Comments must be received by July 5, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 95-NM-38-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. The service information referenced in the proposed rule may be obtained from Fokker Aircraft USA, Inc., 1199 North Fairfax Street, Alexandria, Virginia 22314. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Tim Dulin, Aerospace Engineer, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2141; fax (206) 227-1320.

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 notice may be changed in light of the comments received. 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 notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 95-NM-38-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-103, Attention: Rules Docket No. 95-NM-38-AD, 1601 Lind Avenue SW., Renton, Washington 98055- 4056.

Discussion

The Rijksluchtvaartdienst (RLD), which is the airworthiness authority for the Netherlands, recently notified the FAA that an unsafe condition may exist on certain Fokker Model F28 Mark 0100 series airplanes. The RLD advises that it received a report of insufficient running clearance of the brake units on a Fokker Model F28 Mark 0100 series airplane due to overpressure in the hydraulic return system. Results of an investigation revealed that the outlet check valve of a return filter diaphragm assembly of the hydraulic system was blocked. The probable cause of this blockage was determined to be incorrect manufacturing tolerances, which resulted in extrusion of the lower seal at the inner diameter during installation. The RLD received additional reports concerning the possibility of a hydraulic lock between the diaphragm and the check valve of the filter inlet port. This hydraulic lock could lead to incorrect installation of the filter bowl and element. These conditions, if not corrected, could result in overpressure of the hydraulic return system, which may result in reduced braking performance and/or blown tires due to brake overheating. Fokker has issued Service Bulletin SBF100-29-025, dated December 31, 1993, which describes procedures for replacement of the return filter diaphragm assemblies on hydraulic systems 1 and 2 with modified filter units having new diaphragms. Installation of these modified units will ensure that the outlet check valve of the return filter diaphragm assembly is not blocked, and will eliminate the possibility of a hydraulic lock between the diaphragm and the check valve of the filter inlet port. The RLD classified this service bulletin as mandatory and issued Netherlands airworthiness directive 94-024 (A), dated January 28, 1994, in order to assure the continued airworthiness of these airplanes in the Netherlands. 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 RLD has kept the FAA informed of the situation described above. The FAA has examined the findings of the RLD, reviewed all available information, and determined that AD action is necessary for products of this type design that are [[Page 27705]] certificated for operation in the United States. 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 replacement of the return filter diaphragm assemblies on hydraulic systems 1 and 2 with modified filter units having new diaphragms. The actions would be required to be accomplished in accordance with the service bulletin described previously. As a result of recent communications with the Air Transport Association (ATA) of America, the FAA has learned that, in general, some operators may misunderstand the legal effect of AD's on airplanes that are identified in the applicability provision of the AD, but that have been altered or repaired in the area addressed by the AD. The FAA points out that all airplanes identified in the applicability provision of an AD are legally subject to the AD. If an airplane has been altered or repaired in the affected area in such a way as to affect compliance with the AD, the owner or operator is required to obtain FAA approval for an alternative method of compliance with the AD, in accordance with the paragraph of each AD that provides for such approvals. A note has been included in this notice to clarify this long-standing requirement. The FAA estimates that 119 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 2 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would be provided by the parts manufacturer at no cost to operators. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $14,280, or $120 per airplane. The total cost impact figure discussed above is 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 regulations proposed herein would not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Fokker: Docket 95-NM-38-AD.

Applicability: Model F28 Mark 0100 series airplanes equipped with Aircraft Porous Media Europe (APME) Limited hydraulic return filter assemblies having part numbers (P/N) QA07236 and QA07237, all serial numbers; 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 use the authority provided in paragraph (c) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously. To prevent overpressure in the hydraulic return system, which could result in reduced braking performance and/or blown tires due to brake overheating, accomplish the following: (a) Within 6 months after the effective date of this AD, replace the return filters, P/N's QA07236 and QA07237, on hydraulic systems 1 and 2, respectively, with modified return filter units, in accordance with Fokker Service Bulletin SBF100-29-025, dated December 31, 1993. (b) As of the effective date of this AD, no person shall install on any airplane a return filter unit, P/N QA07236 or QA07237, on hydraulic system 1 or 2, respectively, unless that unit has been modified in accordance with Fokker Service Bulletin SBF100-29-025, dated December 31, 1993. (c) 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, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Standardization Branch, ANM-113.

Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(d) Special flight permits may be issued in accordance with Secs. 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.

Issued in Renton, Washington, on May 19, 1995. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 95-12827 Filed 5-24-95; 8:45 am] BILLING CODE 4910-13-U