[Federal Register Volume 61, Number 121 (Friday, June 21, 1996)]
[Rules and Regulations]
[Pages 31825-31827]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-15602]



-----------------------------------------------------------------------


DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-151-AD; Amendment 39-9674; AD 96-13-06]
RIN 2120-AA64


Airworthiness Directives; Fokker Model F28 Series Airplanes 
(Excluding Fokker Model F28 Mark 0100 Series Airplanes)

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Fokker Model F28 series airplanes, that requires 
replacement of junction fittings of the horizontal stabilizer with 
improved fittings. For certain airplanes, this amendment also requires 
replacement of the drive-fitting bushings and bolts of the horizontal 
stabilizer with improved bushings and bolts. This amendment is prompted 
by reports of stress corrosion cracking in a junction fitting lug of 
the horizontal stabilizer. The actions specified by this 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.

DATES: Effective July 26, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 26, 1996.

ADDRESSES: The service information referenced in this AD may be 
obtained from Fokker Aircraft USA, Inc., 1199 North Fairfax Street, 
Alexandria, Virginia 22314. This information may be examined at the 
Federal Aviation Administration (FAA), Transport Airplane Directorate, 
Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Fokker Model F28 series 
airplanes was published in the Federal Register on

[[Page 31826]]

April 1, 1996 (61 FR 14273). That action proposed to require 
replacement of aluminum 7079 junction fittings (left and right) of the 
horizontal stabilizer with improved fittings made from aluminum 7075. 
For certain airplanes, that action also proposed to 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.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the two comments received.

Support for the Proposal

    Both commenters support the proposed rule.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.

Cost Impact

    The FAA estimates that 14 airplanes of U.S. registry will be 
affected by this AD.
    For airplanes on which the replacement of aluminum 7079 junction 
fittings with improved fittings is required, the FAA estimates that it 
will take approximately 430 work hours per airplane to accomplish the 
replacement, at an average labor rate of $60 per work hour. Required 
parts will cost approximately $40,000 per airplane. Based on these 
figures, the cost impact of the 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 will take approximately 10 work 
hours per airplane to accomplish the replacement, at an average labor 
rate of $60 per work hour. Required parts will cost approximately 
$2,100 per airplane. Based on these figures, the cost impact of the AD 
on U.S. operators for replacement of the drive-fitting bushings and 
bolts is estimated to be $2,700 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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.


Sec. 39.13  [Amended]

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

96-13-06  Fokker: Amendment 39-9674. Docket 95-NM-151-AD.

    Applicability: Model F28 series airplanes; serial numbers 11003 
through 11151 inclusive, 11991, and 11992; certificated in any 
category.

    Note 1: Fokker Model F28 Mark 0100 series airplanes are not 
subject to the requirements of this AD.
    Note 2: 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 3: Information concerning the existence of approved 
alternative methods of

[[Page 31827]]

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.
    (f) The replacements shall be done in accordance with Fokker 
Service Bulletin F28/55-029, Revision 1, dated January 23, 1993, 
which contains the following list of effective pages:

------------------------------------------------------------------------
                                  Revision level                        
            Page No.              shown on page     Date shown on page  
------------------------------------------------------------------------
1-3............................  1..............  Jan. 23, 1993.        
4-45...........................  Original.......  Sep. 20, 1992.        
------------------------------------------------------------------------

This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Fokker Aircraft USA, Inc., 1199 
North Fairfax Street, Alexandria, Virginia 22314. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
    (g) This amendment becomes effective on July 26, 1996.

    Issued in Renton, Washington, on June 13, 1996.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-15602 Filed 6-20-96; 8:45 am]
BILLING CODE 4910-13-U