[Federal Register Volume 61, Number 108 (Tuesday, June 4, 1996)]
[Rules and Regulations]
[Pages 28029-28031]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-13608]



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


DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-172-AD; Amendment 39-9640; AD 96-11-16]
RIN 2120-AA64


Airworthiness Directives; 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 Mark 0100 series airplanes, that 
requires a one-time measurement during refueling to determine the 
pressure in each collector tank; for certain airplanes, non-destructive 
test (NDT) inspections to detect cracking or deformations of the 
collector tank ribs on each wing, and repair, if necessary; and 
modification of top-hat stringers in each outer wing tank. This 
amendment is prompted by a report of damage to the

[[Page 28030]]

ribs of the wing collector tank caused by over-pressure in the 
collector tank during refueling. The actions specified by this AD are 
intended to prevent cracking and deformation of the wing collector 
tanks due to over-pressure, which could result in reduced structural 
integrity of the wing.

DATES: Effective July 9, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 9, 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: Ruth E. Harder, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-1721; 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 Mark 0100 
series airplanes was published in the Federal Register on December 19, 
1995 (60 FR 65256). That action proposed to require:

    1. a one-time measurement during refueling to determine the 
pressure in each collector tank;
    2. for certain airplanes, non-destructive test (NDT) inspections to 
detect cracking or deformations of the collector tank ribs on each 
wing, and repair, if necessary; and
    3. modification of top-hat stringers in each outer wing tank.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposal

    All commenters supported the proposal.

Request Not to Reference New Service Information

    Although all of the commenters support the proposal, they have 
concerns about the recommended compliance times that are specified in a 
recent revision to Fokker Service Bulletin SBF100-57-030. The original 
issue of the service bulletin was referenced in the proposal as the 
appropriate source of service information related to the proposed 
inspection. The commenters point out that Revision 1 of that service 
bulletin, which was released on September 27, 1995, now recommends that 
the inspection be performed within a shorter time period than that 
recommended in the original issue of the service bulletin. The 
commenters state that, if the FAA were to reduce the compliance period 
of the proposed AD as recommended in Revision 1, then they would be 
faced with scheduling problems and/or increased costs resulting from 
airplane downtime and labor.
    The commenters further point out that Fokker's reason for 
recommending the more restrictive compliance time specified in Revision 
1, is that further analyses could not completely exclude the 
possibility of static electricity build-up during refueling. The 
commenters consider this reason to be highly improbable and maintain 
that it does not constitute adequate justification for the reduced 
compliance time.
    For these reasons, the commenters assert that, if the FAA were to 
issue a supplemental proposed rule to propose reducing the compliance 
to correlate with the recommendations of Revision 1 of the service 
bulletin, they would oppose adoption of the AD.
    The FAA responds to these commenters' concern by stating that it 
does not consider reducing the compliance time of this AD to correlate 
with the revised service bulletin to be warranted. The FAA has based 
the compliance time requirements of this AD in consideration of the 
safety implications, the average utilization rate of the affected 
fleet, the practical aspects of an orderly inspection of the fleet 
during regular maintenance periods, and the availability of required 
modification parts. In addition, the FAA has worked in consultation 
with the airworthiness authorities of the Netherlands and with Fokker 
to develop the compliance time. The FAA has determined that the 
compliance time requirements, as specified in the proposal and in this 
final rule, are acceptable to correct the unsafe condition in a timely 
manner.

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 58 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 85 work hours per 
airplane to accomplish the required actions, and that the average labor 
rate is $60 per work hour. Based on these figures, the cost impact of 
the AD on U.S. operators is estimated to be $295,800, or $5,100 per 
airplane.
    The cost impact figure discussed above is 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.

[[Page 28031]]

Sec. 39.13  [Amended]

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

96-11-16 Fokker: Amendment 39-9640. Docket 95-NM-172-AD.

    Applicability: Model F28 Mark 0100 airplanes, serial numbers 
11244 through 11277 inclusive, 11279, 11281 through 11287 inclusive, 
and 11289 through 11400 inclusive, 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 (g) 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 over-pressurization and/or damage to the wing 
collector tanks, which could result in reduced structural integrity 
of the wings, accomplish the following:
    (a) Within 45 days after the effective date of this AD, perform 
a one-time measurement during refueling to determine the pressure in 
each collector tank in accordance with Part 1 of the Accomplishment 
Instructions of Fokker Service Bulletin SBF100-57-030, dated 
December 17, 1994.

    Note 2: Pressure Limits Categories are defined in Table 2 of 
Fokker Service Bulletin SBF100-57-030, dated December 17, 1994.

    (b) For Pressure Limits Category 1: Within 2 years after the 
effective date of this AD, modify the four affected top-hat 
stringers (2.32, 2.33, 2.34, and 2.35) in each outer wing tank area 
by removing the restriction blocks, in accordance with the 
Accomplishment Instructions of Fokker Service Bulletin SBF100-57-
029, Revision 1, dated March 23, 1995.
    (c) For Pressure Limits Categories 2 through 5: Except as 
provided by paragraph (d) of this AD, prior to the number of 
accumulated total flight cycles or within the time specified in 
Table 1 of Fokker Service Bulletin SBF100-57-030, dated December 17, 
1994, whichever occurs earlier, accomplish the requirements of 
paragraphs (c)(1) and (c)(2) of this AD.
    (1) Perform the Non-Destructive Test (NDT) inspections specified 
in Part 2 of the Accomplishment Instructions of Fokker Service 
Bulletin SBF100-57-030, dated December 17, 1994, to detect cracking 
or deformations of the collector tank ribs on each wing at wing 
stations 1825, 2230, and 2635. These inspections are to be performed 
in accordance with Fokker Service Bulletin SBF100-57-030, dated 
December 17, 1994.
    (2) Modify the four affected top-hat stringers (2.32, 2.33, 
2.34, and 2.35) in each outer wing tank area by removing the 
restriction blocks, in accordance with the Accomplishment 
Instructions of Fokker Service Bulletin SBF100-57-029, Revision 1, 
dated March 23, 1995.
    (d) For Pressure Limits Category 6, and for airplanes having 
pressure limits within the limits specified in Categories 3 through 
5 and that have exceeded the number of accumulated total flight 
cycles specified in Table 1: Within 100 flight cycles, accomplish 
the requirements of paragraphs (d)(1) and (d)(2) of this AD.
    (1) Perform the NDT inspections in accordance with the 
procedures of Part 2 of the Accomplishment Instructions of Fokker 
Service Bulletin SBF100-57-030, dated December 17, 1994. The fueling 
pressure must not exceed 25 pounds per square inch (PSI) during 
refueling.
    (2) Modify the four affected top-hat stringers (2.32, 2.33, 
2.34, and 2.35) in each outer wing tank area by removing the 
restriction blocks, in accordance with the Accomplishment 
Instructions of Fokker Service Bulletin SBF100-57-029, Revision 1, 
dated March 23, 1995.
    (e) For Pressure Limits Category 7: Prior to further flight 
following the measurement required by paragraph (a) of this AD, 
accomplish the requirements of paragraphs (e)(1) and (e)(2) of this 
AD.
    (1) Perform the NDT inspections in accordance with the 
procedures of Part 2 of the Accomplishment Instructions of Fokker 
Service Bulletin SBF100-57-030, dated December 17, 1994.
    (2) Modify the four affected top-hat stringers (2.32, 2.33, 
2.34, and 2.35) in each outer wing tank area by removing the 
restriction blocks, in accordance with the Accomplishment 
Instructions of Fokker Service Bulletin SBF100-57-029, Revision 1, 
dated March 23, 1995.
    (f) If any cracking or deformation is detected during any 
inspection required by this AD, prior to further flight, repair in 
accordance with a method approved by the Manager, Standardization 
Branch, ANM-113, FAA, Transport Airplane Directorate.
    (g) 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. 
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 compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (h) 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.
    (i) The measurement and inspections shall be done in accordance 
with Fokker Service Bulletin SBF100-57-030, dated December 17, 1994. 
The modification shall be done in accordance with Fokker Service 
Bulletin SBF100-57-029, Revision 1, dated March 23, 1995. 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.
    (j) This amendment becomes effective on July 9, 1996.

    Issued in Renton, Washington, on May 23, 1996.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-13608 Filed 6-3-96; 8:45 am]
BILLING CODE 4910-13-U