[Federal Register Volume 62, Number 229 (Friday, November 28, 1997)]
[Proposed Rules]
[Pages 63292-63294]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-31159]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-249-AD]
RIN 2120-AA64
Airworthiness Directives; Fokker Model F28 Mark 0070 and 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 Mark 0070
and Mark 0100 series airplanes. This proposal would require a one-time
visual inspection to detect heat damage of the fuselage skin and
stubwing structure. This proposal also would require either repetitive
leak tests of the seals of the bleed air system, or repair of any heat-
damaged structure, as necessary; and replacement of corrujoint seals
with new improved seals. This proposal is prompted by the issuance of
mandatory continuing airworthiness information by a foreign civil
airworthiness authority. The actions specified by the proposed AD are
intended to prevent the leakage of hot air from the corrujoint seals of
the low- and high-pressure check valves located in the stubwings, which
could result in heat damage to the fuselage skin and stubwing
structure, and consequent reduced structural integrity of the airplane.
DATES: Comments must be received by December 29, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-249-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 Services B.V., Technical Support Department, P.O.
Box 75047, 1117 ZN Schiphol Airport, the Netherlands. This information
may be examined at the FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: 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:
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
[[Page 63293]]
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 97-NM-249-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. 97-NM-249-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 Mark 0070 and Mark 0100
series airplanes. The RLD advises that several operators of Fokker
Model F28 Mark 0100 series airplanes have reported bleed air leakage at
corrujoint seals at the 7th stage low-pressure and 12th stage high-
pressure check valves, which are located in the stubwings (engine
pylons). On a few airplanes, leakage of hot air from these joints has
resulted in heat damage to the fuselage skin and stubwing structure,
which required internal and external repairs to ensure structural
integrity. Such heat damage, if not corrected, could result in reduced
structural integrity of the airplane.
Explanation of Relevant Service Information
Fokker has issued Service Bulletin SBF100-53-084, dated July 6,
1996, which describes the following procedures:
An inspection of aircraft maintenance records to determine
whether maintenance was accomplished on certain components for the
bleed air system.
A one-time visual inspection to detect heat damage of the
fuselage skin and stubwing structure.
Repetitive leak tests of the seals of the bleed air
system, or repair of any heat-damaged structure, as necessary.
Replacement of corrujoint seals with new improved seals.
Fokker has also issued Service Bulletin SBF100-36-026, Revision 1,
dated July 6, 1996, which describes procedures for the replacement of
certain corrujoint seals at the 7th stage low-pressure and 12th stage
high-pressure check valves of the left- and right-hand bleed air
systems with new improved seals.
Accomplishment of the actions specified in the service bulletins is
intended to adequately address the identified unsafe condition. The RLD
classified these service bulletins as mandatory and issued Dutch
airworthiness directive BLA 1995-076/2 (A), dated August 30, 1996, in
order to assure the continued airworthiness of these airplanes in the
Netherlands.
FAA's Conclusions
These airplane models are manufactured in the Netherlands and are
type certificated for operation in the United States under the
provisions of Sec. 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.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, the proposed AD would require accomplishment of
the actions specified in the service bulletins described previously,
except as discussed below.
Differences Between Proposed Rule and Service Bulletin
Operators should note that, unlike the procedures described in
Fokker Service Bulletin SBF100-53-084, this proposed AD does not
require an inspection of the maintenance records to determine whether
maintenance was accomplished on certain components (check valves and
corrujoint seals) of the bleed air system. The FAA has determined that
such a records inspection is unnecessary; instead, this AD specifies
applicability to those airplanes equipped with any corrujoint seal
having P/N BE20061 (Rolls-Royce P/N 3405891).
Cost Impact
The FAA estimates that 131 Fokker Model F28 Mark 0070 and Mark 0100
series airplanes of U.S. registry would be affected by this proposed
AD.
The FAA estimates that it would take approximately 3 work hours per
airplane to accomplish the proposed inspection, at an average labor
rate of $60 per work hour. Based on these figures, the cost impact of
this action on U.S. operators is estimated to be $23,580, or $180 per
airplane.
The FAA estimates that it would take approximately 7 work hours per
airplane to replace the corrujoint seals, at an average labor rate of
$60 per work hour. Required parts would cost approximately $80 per
airplane. Based on these figures, the cost impact of this action on
U.S. operators is estimated to be $65,500, or $500 per airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the proposed 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 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 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:
[[Page 63294]]
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:
Fokker: Docket 97-NM-249-AD.
Applicability: Model F28 Mark 0070 and Mark 0100 series
airplanes; as listed in Fokker Service Bulletin SBF100-53-084, dated
July 6, 1996; if equipped with any corrujoint seal having part
number (P/N) BE20061 (Rolls-Royce P/N 3405891); 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 otherwise
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 the leakage of hot air from the corrujoint seals of
low-and high-pressure check valves located in the stubwings, which
could result in heat damage to the fuselage skin and stubwing
structure and consequent reduced structural integrity, accomplish
the following:
(a) Within 3,000 flight hours or 12 months after the effective
date of this AD, whichever occurs first, perform a one-time visual
inspection of the fuselage skin in the left-and right-hand stubwings
to detect heat damage; in accordance with Part 2 of the
Accomplishment Instructions of Fokker Service Bulletin SBF100-53-
084, dated July 6, 1996.
(b) If no heat damage is found during the inspection required by
paragraph (a) of this AD, prior to further flight, perform a leak
test of each corrujoint seal at the 7th stage low-pressure and 12th
stage high-pressure check valves of the left-and right-hand bleed
air systems, in accordance with Part 3 of the Accomplishment
Instructions of Fokker Service Bulletin SBF100-53-084, dated July 6,
1996.
(1) If any leakage is found at a seal, prior to further flight,
replace that seal with a new improved seal having part number
EU15969, in accordance with the Accomplishment Instructions of
Fokker Service Bulletin SBF100-36-026, Revision 1, dated July 6,
1996.
(2) If no leakage is found at a seal, perform an additional leak
test of that seal within 250 flight hours after the initial test.
(i) If no leakage is found during the additional test of the
seal, within 3,000 flight hours after the additional test, replace
the seal with an improved seal having P/N EU15969, in accordance
with the Accomplishment Instructions of Fokker Service Bulletin
SBF100-36-026, Revision 1, dated July 6, 1996.
(ii) If any leakage is found during the additional test of the
seal, prior to further flight, accomplish paragraphs (b)(2)(ii)(A)
and (b)(2)(ii)(B) of this AD.
(A) Replace the seal with a new improved seal having P/N
EU15969, in accordance with the Accomplishment Instructions of
Fokker Service Bulletin SBF100-36-026, Revision 1, dated July 6,
1996.
(B) Inspect the fuselage skin in the applicable left-or right-
hand stubwing to detect heat damage, in accordance with Part 2 of
the Accomplishment Instructions of Fokker Service Bulletin SBF100-
53-084, dated July 6, 1996.
(c) If any heat damage is found during the inspection required
by paragraph (a) or paragraph (b)(2)(ii)(B) of this AD, prior to
further flight, perform a detailed inspection of the fuselage skin
and stubwing structure to detect the extent of heat damage, in
accordance with Parts 4 and 5 of the Accomplishment Instructions of
Fokker Service Bulletin SBF100-53-084, dated July 6, 1996; and
accomplish paragraphs (c)(1) and (c)(2) of this AD.
(1) Repair the affected structure, in accordance with Part 6 of
the Accomplishment Instructions of Fokker Service Bulletin SBF100-
53-084, dated July 6, 1996. And
(2) Replace all corrujoint seals having P/N BE20061 (Rolls-Royce
P/N 3405891) at the 7th stage low-pressure and 12th stage high-
pressure check valves of the left-and right-hand bleed air systems
with new improved corrujoint seals having P/N EU15969, in accordance
with the Accomplishment Instructions of Fokker Service Bulletin
SBF100-36-026, Revision 1, dated July 6, 1996.
(d) As of the effective date of this AD, no person shall install
a corrujoint seal having P/N BE20061 (Rolls-Royce P/N 3405891) on
any airplane.
(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 2: 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.
Note 3: The subject of this AD is addressed in Dutch
airworthiness directive BLA 1995-076/2 (A), dated August 30, 1996.
Issued in Renton, Washington, on November 20, 1997.
Stewart R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-31159 Filed 11-26-97; 8:45 am]
BILLING CODE 4910-13-U
