# Airworthiness Directives; Fokker Model F28 Mark 1000, 2000, 3000, and 4000 Series Airplanes > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A94-8053 ## Record - **Collection:** Federal Register - **Document type:** Uncategorized Document - **Published:** April 5, 1994 ## Text DEPARTMENT OF TRANSPORTATION 14 CFR Part 39 [Docket No. 93-NM-205-AD] Airworthiness Directives; Fokker Model F28 Mark 1000, 2000, 3000, and 4000 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 Fokker Model F28 Mark 1000, 2000, 3000, and 4000 series airplanes. This proposal would require inspection to detect cracking in the area of the side stay attachment lugs of the fitting subassembly of the main landing gear (MLG), and replacement of cracked subassemblies with new or serviceable subassemblies. This proposal is prompted by reports of cracking in the subassembly of the MLG. The actions specified by the proposed AD are intended to prevent damage to and/or failure of the support structure of the MLG. DATES: Comments must be received by May 31, 1994. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 93-NM-205-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: Mark Quam, Aerospace Engineer, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2145; 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 93-NM-205-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. 93-NM-205-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 1000, 2000, 3000, and 4000 series airplanes that are equipped with certain Dowty Aerospace main undercarriage units. The RLD advises that cracking has been found in the fitting subassemblies of the main landing gear (MLG). In three of these instances, the cracking had penetrated completely through the fitting subassemblies from the side stay attachment lug to the main bore, which resulted in loss of damping fluid. In another incident, cracking was found in the web section that is adjacent to the inner attachment bores of the side stay of the fitting subassembly of the MLG. Investigation into the cause of this cracking revealed that damage to the anodic film resulted in corrosion of these subassemblies. Cracking in the fitting subassemblies of the MLG, if not corrected, could result in damage to and/or failure of the support structure of the MLG. Fokker has issued Service Bulletin F28/32-149, dated August 30, 1991, that describes procedures for an eddy current inspection to detect cracking in the area of the side stay attachment lugs of the fitting subassembly of the MLG. The RLD classified this service bulletin as mandatory and issued Netherlands Airworthiness Directive (BLA) 91-080, Issue 2, dated February 21, 1992, in order to assure the continued airworthiness of these airplanes in the Netherlands. Additionally, Dowty Aerospace Gloucester, which is the manufacturer of the main undercarriage units installed on these airplanes, has issued Service Bulletin 32-161R, Revision 2, dated January 7, 1992, that describes procedures for replacement of any cracked subassembly with a new subassembly, or a serviceable subassembly that has been identified previously with service bulletin number ``32-161R'' on its nameplate. The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, classified this service bulletin as mandatory and issued CAA Airworthiness Directive 023-06-91 in order to assure the continued airworthiness of these aviation products in the United Kingdom. The Fokker service bulletin references this Dowty Aerospace Gloucester service bulletin. 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 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 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 an eddy current inspection to detect cracking in the area of the side stay attachment lugs of the fitting subassembly of the MLG. The actions would be required to be accomplished in accordance with the Fokker service bulletin described previously. This proposal would also require replacement of any cracked fittings with new or serviceable fittings in accordance with the Dowty Aerospace Gloucester service bulletin described previously. The FAA estimates that 42 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 14 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $55 per work hour. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $32,340, or $770 per airplane. This total cost figure assumes that no operator has yet accomplished the proposed requirements of this AD action. 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 14 CFR part 39 of the Federal Aviation Regulations 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 93-NM-205-AD. Applicability: Model F28 Mark 1000, 2000, 3000, and 4000 series airplanes, serial numbers 11003 through 11241 inclusive, 11991, and 11992; certificated in any category, and equipped with any of the following Dowty Aerospace Gloucester main undercarriage unit part numbers: 200427003/004/005/006/007/008/009/010, 200633001/002/005/006, 200642001/002/003/004/005/006, 200739001/002/003/004, 200752001/002/003/004, or 200782001/002/003/004/005/006/007/008. Compliance: Required as indicated, unless accomplished previously. To prevent damage to and/or failure of the support structure of the main landing gear (MLG), accomplish the following: (a) Within 3 months after the effective date of this AD, perform an eddy current inspection to detect cracking in the area of the side stay attachment lugs of the fitting subassembly of the MLG in accordance with Fokker Service Bulletin F28/32-149, dated August 30, 1991. If any cracked subassembly is found, prior to further flight, replace with a new subassembly, or a serviceable subassembly that has been identified previously with service bulletin number ``32- 161R'' on its nameplate; in accordance with Dowty Aerospace Gloucester Service Bulletin 32-161R, Revision 2, dated January 7, 1992. (b) As of the effective date of this AD, no person shall install on any airplane a main undercarriage unit, having any of the following Dowty Aerospace Gloucester part numbers, that has not been identified previously with service bulletin number ``32-161R'' on its nameplate: 200427003/004/005/006/007/008/009/010, 200633001/002/005/006, 200642001/002/003/004/005/006, 200739001/002/003/004, 200752001/002/003/004, or 200782001/002/003/004/005/006/007/008. (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: 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 Federal Aviation Regulations (FAR) 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 March 30, 1994. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 94-8053 Filed 4-4-94; 8:45 am] BILLING CODE 4910-13-U --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A94-8053. Public record. Not legal advice.