[Federal Register Volume 62, Number 35 (Friday, February 21, 1997)]
[Rules and Regulations]
[Pages 7924-7926]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-3695]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-32-AD; Amendment 39-9932; AD 97-04-08]
RIN 2120-AA64
Airworthiness Directives; Fokker Model F27 Mark 050, 100, 200,
300, 400, 600, and 700 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 F27 Mark 050, 100, 200, 300, 400,
600, and 700 series airplanes, that requires an ultrasonic inspection
to determine if certain tubes are installed in the drag stay units of
the main landing gear (MLG), and various follow-on actions. This
amendment is prompted by a report that, due to fatigue cracking from an
improperly machined radius of the inner tube, a drag stay broke, and,
consequently, lead to the collapse of the MLG during landing. The
actions specified by this AD are intended to prevent such fatigue
cracking, which could result in reduced structural integrity or
collapse of the MLG.
DATES: Effective March 28, 1997.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 28, 1997.
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: Ruth 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 F27 Mark 050,
100, 200, 300, 400, 600, and 700 series airplanes was published in the
Federal Register on October 31, 1996 (61 FR 56170). That action
proposed to require an ultrasonic inspection to determine if certain
tubes are installed on the DSUs of the MLG, and various follow-on
actions.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. No comments were submitted in response
to the proposal or the FAA's determination of the cost to the public.
Conclusion
The FAA has determined that air safety and the public interest
require the adoption of the rule as proposed.
[[Page 7925]]
Cost Impact
The FAA estimates that 10 Model F27 Mark 050, 100, 200, 300, 400,
600, and 700 series airplanes of U.S. registry will be affected by this
AD, that it will take approximately 2 work hours per airplane to
accomplish the required inspection, at an average labor rate of $60 per
work hour. Based on these figures, the cost impact of the inspection
required by this AD on U.S. operators is estimated to be $1,200, or
$120 per airplane. This cost impact figure 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.
There currently are no Fokker Model F27 Mark 050 series airplanes
on the U.S. Register that will require the inspection of the DSU. The
only airplanes that will require this inspection are currently operated
by non-U.S. operators under foreign registry; therefore, they are not
directly affected by this AD action. However, the FAA considers that
inclusion of these airplanes in the applicability of this rule is
necessary to ensure that the unsafe condition is addressed in the event
that any of these airplanes are imported and placed on the U.S.
Register in the future.
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:
97-04-08 Fokker: Amendment 39-9932. Docket 96-NM-32-AD.
Applicability: Model F27 Mark 050, 100, 200, 300, 400, 600, and
700 series airplanes, equipped with Dowty Aerospace main landing
gear (MLG) drag stay units (DSU) having part number (P/N) 200684001,
200261001, or 200485001; 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 (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 fatigue cracking in drag stay unit of the MLG, which
could result in reduced structural integrity or collapse of the MLG,
accomplish the following:
(a) Within 60 days after the effective date of this AD, perform
an ultrasonic inspection to determine if a tube having part number
(P/N) 200485300 with a straight bore, or a tube having P/N 200259300
with a change in section (stepped bore), is installed on the DSU's
of the MLG, in accordance with Fokker Service Bulletin F27/32-167,
dated November 19, 1993 (for Model F27 Mark 100, 200, 300, 400, 600,
and 700 series airplanes), or Fokker Service Bulletin SBF50-32-029,
dated February 11, 1994 (for Model F27 Mark 050 series airplanes),
as applicable.
Note 2: Fokker Service Bulletin F27/32-167 references Dowty
Service Bulletins 23-169B and 32-82W; and Fokker Service Bulletin
SBF50-32-029 references Dowty Service Bulletin F50-32-50; as
additional sources of service information for procedures to
accomplish the actions specified in this AD.
(b) For all airplanes: If any tube having P/N 200485300 with a
straight bore is found installed during the inspection required by
paragraph (a) of this AD, prior to further flight, reidentify it in
accordance with Fokker Service Bulletin F27/32-167, dated November
19, 1993 (for Model F27 Mark 100, 200, 300, 400, 600, and 700 series
airplanes); or Fokker Service Bulletin SBF50-32-029, dated February
11, 1994 (for Model F27 Mark 050 series airplanes); as applicable.
(c) For Model F27 Mark 50 series airplanes: If any tube having
P/N 200259300 with a change in section (stepped bore) is found
installed during the inspection required by paragraph (a) of this
AD, prior to further flight, replace the DSU with a new or
serviceable DSU having P/N 200684004, in accordance with Fokker
Service Bulletin SBF50-32-029, dated February 11, 1994.
(d) For F27 Mark 100, 200, 300, 400, 600, and 700 series
airplanes: If any tube having P/N 200259300 with a change in section
(stepped bore) is found installed during the inspection required by
paragraph (a) of this AD, prior to further flight, re-identify the
DSU in accordance with Fokker Service Bulletin F27/32-167, dated
November 19, 1993. Following accomplishment of the re-
identification, prior to further flight, perform an ultrasonic
inspection to detect cracks in the re-identified DSU's, in
accordance with that service bulletin.
(1) For airplanes equipped with any DSU re-identified as P/N
200684003, 200261003, or 200485003: If no crack is detected, no
further action is required by this AD.
(2) For airplanes equipped with any DSU re-identified as P/N
200684002, 200261002, or 200485002: If no crack is detected,
accomplish paragraphs (c)(2)(i) and (c)(2)(ii) of this AD.
(i) Repeat the ultrasonic inspection required by paragraph (d)
of this AD thereafter at intervals not to exceed 1,500 flight
cycles.
(ii) At the next MLG overhaul, but no later than 12,000 flight
cycles after the effective date of this AD, rework and re-identify
the DSU again, or replace the DSU with a re-identified DSU, in
accordance with the service bulletin. Accomplishment of the rework
and re-identification, or replacement constitutes terminating action
for the repetitive inspection requirements of this AD.
(3) If any crack signal indication of any DSU tube is greater
than or equal to 80 percent, prior to further flight, replace the
DSU with a re-identified DSU, in accordance with the service
bulletin.
(4) If any crack signal indication of any DSU tube is greater
than or equal to 1 percent but less than 80 percent, accomplish
paragraphs (d)(4)(i) and (d)(4)(ii) of this AD.
(i) Repeat the ultrasonic inspection required by paragraph (d)
of this AD thereafter at intervals not to exceed 1,500 flight
cycles.
(ii) At the next MLG overhaul, but no later than 12,000 flight
cycles after the effective
[[Page 7926]]
date of this AD, replace the DSU with a re-identified DSU, in
accordance with the service bulletin. Accomplishment of the
replacement constitutes terminating action for the repetitive
inspection requirements of 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, 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 compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(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 F27/32-167, dated November 19, 1993; or Fokker Service
Bulletin SBF50-32-029, dated February 11, 1994; as applicable. 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.
(h) This amendment becomes effective on March 28, 1997.
Issued in Renton, Washington, on February 7, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-3695 Filed 2-20-97; 8:45 am]
BILLING CODE 4910-13-U
