[Federal Register Volume 61, Number 63 (Monday, April 1, 1996)]
[Proposed Rules]
[Pages 14273-14275]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-7854]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-151-AD]


Airworthiness Directives; Fokker Model F28 Series Airplanes 
(Excluding 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 series 
airplanes. This proposal would require replacement of certain junction 
fittings of the horizontal stabilizer with improved fittings. For 
certain airplanes, the proposal also would require replacement of the 
drive-fitting bushings and bolts of the horizontal stabilizer with 
improved bushings and bolts. This proposal is prompted by reports of 
stress corrosion cracking in a junction fitting lug of the horizontal 
stabilizer. The actions specified by the proposed AD are intended to 
prevent such cracking, which could result in failure of a lug and 
uncommanded movement of the horizontal stabilizer. This condition, if 
not corrected, could result in reduced controllability of the airplane.


[[Page 14274]]

DATES: Comments must be received by May 9, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-151-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) 227-1149.

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-151-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-151-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Rijksluchtvaartdienst (RLD), which is the airworthiness 
authority for the Netherlands, notified the FAA that an unsafe 
condition may exist on certain Fokker Model F28 series airplanes. The 
RLD advises that it has received several reports indicating that 
cracking was found in the right-hand upper lug of the junction fitting 
of the horizontal stabilizer on these airplanes. This cracking has been 
attributed to stress corrosion. Such cracking can result in failure of 
a lug. Although ultimate load can be carried by the structure with one 
lug failure, uncommanded movement of the horizontal stabilizer can 
occur. This condition, if not corrected, could result in reduced 
controllability of the airplane.
    Fokker has issued Service Bulletin F28/55-029, Revision 1, dated 
January 23, 1993, which describes procedures for replacement of 
aluminum 7079 junction fittings (left and right) of the horizontal 
stabilizer with improved junction fittings made from aluminum 7075, 
which is much less sensitive to stress corrosion cracking. For certain 
airplanes, the service bulletin also describes procedures for 
replacement of the drive-fitting bushings and bolts of the horizontal 
stabilizer with new bushings and bolts made from a different material 
having improved resistance to corrosion. The RLD classified this 
service bulletin as mandatory and issued Dutch airworthiness directive 
BLA 92-119, dated October 23, 1992, 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 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, the 
proposed AD would require replacement of aluminum 7079 junction 
fittings (left and right) of the horizontal stabilizer with improved 
fittings made from aluminum 7075. For certain airplanes, the proposed 
AD also would require replacement of the drive-fitting bushings and 
bolts of the horizontal stabilizer with new bushings and bolts made 
from a different material having improved resistance to corrosion. The 
actions would be required to be accomplished in accordance with the 
service bulletin described previously.
    Operators should note that the compliance time specified in the 
Dutch airworthiness directive for accomplishment of the replacements 
differs from that specified in this proposed AD. In developing an 
appropriate compliance time, the FAA considered the safety 
implications, parts availability, and normal maintenance schedules for 
timely accomplishment of the replacements. In light of these items, the 
FAA has determined that 18 months for compliance is appropriate.
    The FAA estimates that 14 airplanes of U.S. registry would be 
affected by this proposed AD.
    For airplanes on which replacement of aluminum 7079 junction 
fittings with improved fittings is required, the FAA estimates that it 
would take approximately 430 work hours per airplane to accomplish the 
replacement, at an average labor rate of $60 per work hour. Required 
parts would cost approximately $40,000 per airplane. Based on these 
figures, the cost impact of the proposed AD on U.S. operators for 
replacement of aluminum 7079 fittings is estimated to be $65,800 per 
airplane.
    For airplanes on which replacement of the drive-fitting bushings 
and bolts on the horizontal stabilizer with new bushings and bolts is 
required, the FAA estimates that it would take approximately 10 work 
hours per airplane to accomplish the replacement, at an average labor 
rate of $60 per work hour. Required parts would cost approximately 
$2,100 per airplane. Based on these figures, the cost impact of the 
proposed AD on U.S. operators for replacement of the drive-fitting 
bushings and bolts is estimated to be $2,700 per airplane.
    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

[[Page 14275]]
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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

Fokker: Docket 95-NM-151-AD.

    Applicability: Model F28 series airplanes (excluding Model F28 
Mark 0100 series airplanes); serial numbers 11003 through 11151 
inclusive, 11991, and 11992; 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 request approval for an 
alternative method of compliance in accordance with paragraph (d) 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.
    To prevent stress corrosion cracking of the junction fitting lug 
of the horizontal stabilizer, which could result in failure of the 
lug and uncommanded movement of the horizontal stabilizer, and 
subsequent reduced controllability of the airplane; accomplish the 
following:
    (a) Within 18 months after the effective date of this AD, 
replace the aluminum 7079 junction fittings (left and right) of the 
horizontal stabilizer with improved fittings made from aluminum 
7075, in accordance with Part 1 of the Accomplishment Instructions 
of Fokker Service Bulletin F28/55-029, Revision 1, dated January 23, 
1993.
    (b) For airplanes on which the drive-fitting bushings and bolts 
of the horizontal stabilizer have not been replaced in accordance 
with Fokker Service Bulletin F28/55-24: Within 18 months after the 
effective date of this AD, replace the drive-fitting bushings and 
bolts of the horizontal stabilizer with new bushings and bolts, in 
accordance with Part 2 of the Accomplishment Instructions of Fokker 
Service Bulletin F28/55-029, Revision 1, dated January 23, 1993.
    (c) Accomplishment of the replacements required by paragraphs 
(a) and (b) of this AD constitute terminating action for the 
inspections identified as item 55-50-05 in the Fokker Structural 
Integrity Program (SIP) Document 28438, Part 1, revised up through 
October 15, 1992, which are required by AD 93-13-04, amendment 39-
8617 (58 FR 38513, July 19, 1993). Once these replacements are 
accomplished, the life limits of the fitting lugs (identified as 
items 55-50-01 and 55-50-02 in the SIP Document) no longer apply.
    (d) 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.

    (e) 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.

    Issued in Renton, Washington, on March 26, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-7854 Filed 3-29-96; 8:45 am]
BILLING CODE 4910-13-U