[Federal Register Volume 63, Number 11 (Friday, January 16, 1998)]
[Rules and Regulations]
[Pages 2596-2598]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-822]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-NM-94-AD; Amendment 39-10285; AD 98-02-03]
RIN 2120-AA64
Airworthiness Directives; Fokker Model F28 Mark 0100 and Mark
0070 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Fokker Model F28 Mark 0100 and Mark 0070 series
airplanes, that requires modification of the hook and latch engagement
assemblies of the engine cowl doors, measurement of the aerodynamic
mismatch between the fixed cowl and lower cowl door, and repair, if
necessary. This amendment is prompted by reports of operational
experience that indicate that an aerodynamic mismatch may exist between
the fixed engine cowl and the lower cowl door, and may be the result of
one or more hooks of the engagement assemblies not engaging adequately.
This condition may cause the other hooks to carry loads higher than
they were originally designed to carry, and could result in the failure
of those hooks that are engaged. The actions specified by this AD are
intended to prevent possible separation of the lower cowling from the
airplane due to failure of the hooks of the engagement assemblies.
DATES: Effective February 20, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of February 20, 1998.
ADDRESSES: The service information referenced in this AD may be
obtained from Fokker Services B.V., Technical Support Department, P. O.
Box 75047, 1117 ZN Schiphol Airport, the Netherlands. 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: Norman B. Martenson, Manager,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2110; fax (425) 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
and Mark 0070 series airplanes was published in the Federal Register on
November 5, 1996 (61 FR 56925). That action proposed to require
modification of the hook and latch engagement assemblies of the engine
cowl doors, measurement of the aerodynamic mismatch between the fixed
cowl and lower cowl door, and repair, if necessary.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Request to Extend the Compliance Time
Two commenters request that the compliance time for accomplishing
the proposed inspection specified in paragraph (a)(2) of the AD be
changed from ``Within 2,500 flight cycles since the last inspection * *
*'' to `` Within 2,500 flight cycles or 3,500 flight hours since the
last inspection * * *, whichever occurs later.'' One of these
commenters states that it is currently accomplishing the proposed
inspection on its fleet of Fokker Model F28 Mark 0100 series airplanes
during its regularly scheduled maintenance checks at 3,500 flight hour
intervals. The commenter notes that the proposed 2,500 flight cycle
inspection time may fall short of its currently scheduled 3,500 flight
hour maintenance check.
The FAA does not concur with the commenters' request to change the
[[Page 2597]]
compliance time. The FAA points out that the proposed compliance time
of paragraph (a)(2) of the AD was developed in consideration of not
only the degree of urgency associated with addressing the unsafe
condition, but such factors as the manufacturer's and the foreign
airworthinesss authority's [i.e., Rijksluchtvaartdienst (RLD)]
recommendations, and the practical aspect of inspecting the affected
airplanes within an interval of time that parallels normal scheduled
maintenance for the majority of affected operators.
Based on the average utilization rate of the worldwide fleet of
Fokker Model F28 Mark 0100 series airplanes (approximately 1 flight
hour per flight cycle), the request to include a 3,500 flight hour
compliance time option, if granted, would be approximately equal to
3,500 flight cycles. This option would result in a 1,000 flight cycle
extension to the compliance time. The commenters have not provided any
data to substantiate why extending the compliance time by approximately
1,000 flight cycles would not compromise safety. However, under the
provisions of paragraph (e) of the final rule, the FAA may approve
requests for adjustments to the compliance time if sufficient data are
submitted to substantiate that such an adjustment would provide an
acceptable level of safety.
Service Bulletin Change Notification
One commenter states that certain errors were found in the service
information referenced in the proposed AD. Paragraph C.(2) of Part 2 of
the Accomplishment Instructions of Fokker Service Bulletin SBF100-71-
019, dated March 21, 1996, should refer to Figure 5 (not Figure 4) for
dimensions X and Y. Additionally, Figure 5 of the service bulletin
should refer to Figure 6 (not Figure 5) for tool geometry.
The FAA agrees with the commenter. Since issuance of the proposal,
Fokker has issued Service Bulletin Change Notification (SBCN) SBF100-
71-019/1, dated February 28, 1997, which revises paragraph C.(2) of
Part 2 of the Accomplishment Instructions of Fokker Service Bulletin
SBF100-71-019 to correctly reference Figure 5 for dimensions X and Y.
The final rule has been revised to reference SBCN SBF100-71-019/1,
dated February 28, 1997, in addition to the previously referenced
service information.
In addition, the FAA has determined that the reference in Figure 5
to Figure 5 (rather than Figure 6) for tool geometry is merely a
typographical error, since paragraph C.(2) of Part 2 of the
Accomplishment Instructions of Fokker Service Bulletin SBF100-71-019
states ``As a reference, to obtain the correct measurements, use tool
as shown in Figures 5 and 6.'' However, the FAA has forwarded
information regarding this error to Fokker Services.
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 with the change previously
described. The FAA has determined that this change will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Cost Impact
The FAA estimates that 124 Fokker Model F28 Mark 0100 and 0070
series airplanes of U.S. registry will be affected by this AD, that it
will take approximately 3 work hours per airplane to accomplish the
initial inspection and modification, 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 $22,320, or $180 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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
98-02-03 Fokker: Amendment 39-10285. Docket 95-NM-94-AD.
Applicability: Model F28 Mark 0100 and Mark 0070 series
airplanes as listed in Fokker Service Bulletin SBF100-71-019, dated
March 21, 1996, as revised by Fokker Service Bulletin Change
Notification SBF100-71-019/1, dated February 28, 1997; certificated
in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise 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 (e) 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 separation of the lower cowling from the airplane due
to failure of the hook and latch engagement assembly of the cowl
door, accomplish the following:
(a) Accomplish the requirements of paragraph (b) of this AD at
the latest of the times indicated in paragraphs (a)(1), (a)(2), and
(a)(3) of this AD:
(1) Prior to the accumulation of 2,500 total flight cycles; or
(2) Within 2,500 flight cycles since the last inspection
performed in accordance with Fokker Service Bulletin SBF100-71-003,
dated April 14, 1989; Revision 1, dated August 8, 1989, or Revision
2, dated November 21, 1994; or
(3) Within 30 days after the effective date of this AD.
[[Page 2598]]
(b) At the time specified in paragraph (a) of this AD,
accomplish the actions specified in either paragraph (b)(1) or
(b)(2) of this AD, as applicable:
(1) For airplanes specified in Part 1 of Fokker Service Bulletin
SBF100-71-019, dated March 21, 1996, as revised by Fokker Service
Bulletin Change Notification SBF100-71-019/1, dated February 28,
1997: Modify the hook and latch engagement assemblies of the left
and right engine cowl doors, and inspect to determine the
aerodynamic mismatch between the fixed cowl and lower cowl door; in
accordance with Part 1 of the Accomplishment Instructions of Fokker
Service Bulletin SBF100-71-019, dated March 21, 1996, as revised by
Fokker Service Bulletin Change Notification SBF100-71-019/1, dated
February 28, 1997.
Note 2: Accomplishment of the modification of the hook and latch
engagement assemblies of the left and right engine cowl doors, in
accordance with Part 1 of the Accomplishment Instructions of Fokker
Service Bulletin SBF100-71-003, dated April 14, 1989; Revision 1,
dated August 8, 1989; or Revision 2, dated November 21, 1994; is
considered acceptable for compliance with the applicable
modification specified in paragraph (b)(1) of this amendment.
(2) For airplanes specified in Part 2 of Fokker Service Bulletin
SBF100-71-019, dated March 21, 1996, as revised by Fokker Service
Bulletin Change Notification SBF100-71-019/1, dated February 28,
1997, excluding those airplanes subject to paragraph (b)(1) of this
AD: Perform a one-time inspection to determine the aerodynamic
mismatch between the fixed cowl and the lower cowl door, in
accordance with Part 2 of the Accomplishment Instructions of Fokker
Service Bulletin SBF100-71-019, dated March 21, 1996, as revised by
Fokker Service Bulletin Change Notification SBF100-71-019/1, dated
February 28, 1997.
(c) If the aerodynamic mismatch measured between the fixed cowl
and lower cowl door is less than or equal to 4.5 mm, no further
action is required by this AD.
(d) If the aerodynamic mismatch measured between the fixed cowl
and lower cowl door is greater than 4.5 mm, prior to further flight,
perform a one-time inspection to measure the mis-engagement between
the left and right engine hooks of the fixed cowl door and the
clevis fittings of the lower cowl door; in accordance with Part 2 of
the Accomplishment Instructions of Fokker Service Bulletin SBF100-
71-019, dated March 21, 1996, as revised by Fokker Service Bulletin
Change Notification SBF100-71-019/1, dated February 28, 1997.
(1) If the mis-engagement is less than or equal to 6.5 mm, no
further action is required by this AD.
(2) If the mis-engagement is greater than 6.5 mm: Within 1 year
after measuring the mis-engagement required by this paragraph,
modify the mid-clevis fitting on the right and left engine lower
cowl door; in accordance with Part 3 of the Accomplishment
Instructions of Fokker Service Bulletin SBF100-71-019, dated March
21, 1996, as revised by Fokker Service Bulletin Change Notification
SBF100-71-019/1, dated February 28, 1997. After accomplishment of
this modification, no further action is required by this AD.
(e) 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, International Branch, ANM-116, 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, International
Branch, ANM-116.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
(f) 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.
(g) The actions shall be done in accordance with Fokker Service
Bulletin SBF 100-71-019, dated March 21, 1996, as revised by Fokker
Service Bulletin Change Notification SBF 100-71-019/1, dated
February 28, 1997. 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
Services B.V., Technical Support Department, P.O. Box 75047, 1117 ZN
Schiphol Airport, the Netherlands. 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.
Note 4: The subject of this AD is addressed in Dutch
airworthiness directive 1989-049/3 (A), dated June 28, 1996.
(h) This amendment becomes effective on February 20, 1998.
Issued in Renton, Washington, on January 7, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-822 Filed 1-15-98; 8:45 am]
BILLING CODE 4910-13-U
