[Federal Register Volume 59, Number 65 (Tuesday, April 5, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-8053]


[[Page Unknown]]

[Federal Register: April 5, 1994]


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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).

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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 
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