[Federal Register Volume 63, Number 217 (Tuesday, November 10, 1998)]
[Proposed Rules]
[Pages 62970-62973]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-30052]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-202-AD]
RIN 2120-AA64
Airworthiness Directives; Fokker Model F.28 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 supersedure of an existing
airworthiness directive (AD), applicable to certain Fokker Model F.28
Mark 0070 and Mark 0100 series airplanes, that currently requires a
one-time inspection for heat damage of the fuselage skin and stubwing
structure; either repetitive tests of certain seals or repair of heat
damage, as necessary; and eventual replacement of corrujoint seals with
new, improved seals. This action would add a requirement for repetitive
inspections for heat damage of the subject area, and would provide for
a new optional terminating action for the repetitive inspections. This
proposal is prompted by issuance of mandatory continuing airworthiness
information by a foreign civil airworthiness authority. The actions
specified by the proposed AD are intended to prevent leakage of hot air
from the corrujoint seals of certain valves in the stubwings, and
subsequent heat damage of the fuselage skin and stubwing structure,
which could result in reduced structural integrity of the airplane.
DATES: Comments must be received by December 10, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-202-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: 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:
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 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
[[Page 62971]]
Docket Number 98-NM-202-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-114, Attention: Rules
Docket No. 98-NM-202-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On March 31, 1998, the FAA issued AD 98-08-01, amendment 39-10450
(63 FR 17318, April 9, 1998), applicable to certain Fokker Model F.28
Mark 0070 and Mark 0100 series airplanes. That AD requires a one-time
visual inspection to detect heat damage of the fuselage skin and
stubwing structure; either repetitive leak tests of the seals of the
bleed air system or repair of any heat-damaged structure, as necessary;
and eventual replacement of corrujoint seals with new, improved seals.
That action was prompted by the issuance of mandatory continuing
airworthiness information by a foreign civil airworthiness authority.
The requirements of that 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.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, the Rijksluchtvaartdienst (RLD),
which is the airworthiness authority for the Netherlands, has advised
the FAA that the unsafe condition addressed in AD 98-08-01 may exist or
develop on certain Fokker Model F.28 Mark 0070 and Mark 0100 series
airplanes despite compliance with the requirements of that AD. Based on
the results of the one-time visual inspection (required by AD 98-08-
01), the manufacturer has recommended, and the RLD has mandated, that a
visual inspection be repeated at specified intervals to detect heat
damage of the fuselage skin and stubwing connection angles in the
stubwing area.
Explanation of Relevant Service Information
Fokker has issued Service Bulletin SBF100-53-087, dated November
17, 1997, which describes procedures for repetitive visual inspections
to detect heat damage of the fuselage skin and stubwing connection
angles in the stubwing area. This service bulletin also describes
procedures for an additional detailed inspection of the fuselage skin
and stubwing structure, and repair when overheat damage is detected.
Accomplishment of the actions specified in Fokker Service Bulletin
SBF100-53-087 is intended to adequately address the identified unsafe
condition. The RLD classified Fokker Service Bulletin SBF100-53-087 as
mandatory and issued Dutch airworthiness directive 1995-076/3 (A),
dated November 28, 1997, in order to assure the continued airworthiness
of these airplanes in the Netherlands.
Fokker also has issued Proforma Service Bulletin SBF100-36-027,
including Appendix I, both dated March 21, 1997, which describes
procedures for modification of the fuselage skin and stubwing structure
to improve heat protection. The modification involves installing new
heat shields on the fuselage skin, relocating the aft bay overheat
switch, and replacing insulation blankets of the bleed air ducts with
new, improved insulation blankets. This service bulletin specifies that
accomplishment of the modification would eliminate the need for the
repetitive inspections described in Fokker Service Bulletin SBF100-53-
087. The RLD has approved Fokker Service Bulletin SBF100-36-027 and
classified it as optional.
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 section 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 supersede AD 98-08-01,
amendment 39-10450 (63 FR 17318, April 9, 1998), to continue to require
a one-time visual inspection to detect heat damage of the fuselage skin
and stubwing structure; 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. Additionally, this proposal would require repetitive inspections
of the fuselage skin and stubwing connection angles to detect heat
damage, and an additional detailed inspection of the fuselage and
stubwing structure and repair when heat damage is detected. This
proposal also would provide for a new optional terminating action for
the repetitive inspections.
FAA's Determination
Operators should note that, in consonance with the findings of the
RLD, the FAA has determined that the repetitive inspections proposed by
this AD can be allowed to continue in lieu of accomplishment of a
terminating action. In making this determination, the FAA considers
that, in this case, long-term continued operational safety will be
adequately assured by accomplishing the repetitive inspections to
detect heat damage to the fuselage skin and stubwing structure before
the damage represents a hazard to the airplane.
Difference Between Proposed Rule and Relevant Service Information
Operators should note that Fokker Service Bulletin SBF100-53-087
specifies that heat damage of the fuselage skin should be repaired in
accordance with Fokker Service Bulletin SBF100-53-084, dated July 6,
1996, which describes procedures for certain repairs of heat damage,
and recommends that the manufacturer may be contacted for disposition
of other repairs. This proposal would require such other repairs to be
accomplished in accordance with a method approved by either the FAA or
the RLD (or its delegated agent). In light of the type of repair that
would be required to address the identified unsafe condition, and in
consonance with existing bilateral airworthiness agreements, the FAA
has determined that, for this proposed AD, a repair approved by either
the FAA or the RLD would be acceptable for compliance with this
proposed AD.
Explanation of Changes Made to Applicability
Operators should note that the applicability of the proposed AD
differs from the applicability of AD 98-08-01 in that it excludes those
airplanes on which Fokker Proforma Service Bulletin SBF100-36-027 has
been accomplished. The FAA has determined that accomplishment of the
actions described in that service bulletin would terminate the
requirements of the new repetitive visual inspections of the
[[Page 62972]]
fuselage skin in the left- and right-hand stubwings.
Cost Impact
The FAA estimates that 141 airplanes of U.S. registry would be
affected by this proposed AD.
The one-time visual inspection that was previously required by AD
98-08-01, and retained in this AD, takes approximately 3 work hours per
airplane to accomplish, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of the one-time inspection
requirement of this AD on U.S. operators is estimated to be $180 per
airplane.
The seal replacement that was previously required by AD 98-08-01,
and retained in this AD, takes approximately 7 work hours per airplane
to accomplish, at an average labor rate of $60 per work hour. Required
parts cost approximately $80 per airplane. Based on these figures, the
cost impact of the seal replacement requirement of this AD on U.S.
operators is estimated to be $500 per airplane.
The repetitive inspections proposed by this AD would take
approximately 3 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the repetitive inspections proposed by this AD on U.S.
operators is estimated to be $25,380, or $180 per airplane, per
inspection cycle.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the current or 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:
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 removing amendment 39-10450 (63 FR
17318, April 9, 1998), and by adding a new airworthiness directive
(AD), to read as follows:
Fokker Services B.V.: Docket 98-NM-202-AD. Supersedes AD 98-08-01,
Amendment 39-10450.
Applicability: Model F.28 Mark 0070 and Mark 0100 series
airplanes equipped with any corrujoint seal having part number (P/N)
BE20061 (Rolls-Royce P/N 3405891) or on which Fokker Proforma
Service Bulletin SBF100-36-027, including Appendix 1, both dated
March 21, 1997, has not been accomplished; 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 (i)(1)
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 leakage of hot air from the corrujoint seals of the
low- and high-pressure check valves located in the stubwings, and
subsequent heat damage of fuselage skin and stubwing structure
adjacent to bleed air system components in the stubwings, which
could result in reduced structural integrity of the airplane,
accomplish the following:
Restatement of Requirements of AD 98-08-01, Amendment 39-10450
(a) For Model F28 Mark 0070 and Mark 0100 series airplanes as
listed in Fokker Service Bulletin SFB100-53-084, dated July 6, 1996;
if equipped with any corrujoint seal having P/N BE20061 (Rolls-Royce
P/N 3405891): Within 3,000 flight hours or 12 months after May 14,
1998 (the effective date of AD 98-08-01, amendment 39-10450),
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 SFB100-53-084, 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, accomplish either
paragraph (b)(1) or (b)(2) of this AD.
(1) 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.
(2) 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.
(i) 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.
(ii) If no leakage is found at a seal, perform an additional
leak test of that seal within 250 flight hours after the initial
test.
(A) 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.
(B) If any leakage is found during the additional test of the
seal, prior to further flight, 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; and 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
[[Page 62973]]
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) Except as provided by paragraph (g) of this AD: 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 May 14, 1998, no person shall install a corrujoint
seal having P/N BE20061 (Rolls-Royce P/N 3405891) on any airplane.
New Requirements for This AD
(e) For Model F.28 Mark 0070 and Mark 0100 series airplanes on
which Fokker Proforma Service Bulletin SBF100-36-027, including
Appendix 1, both dated March 21, 1997, has not been accomplished:
Perform a visual inspection of the fuselage skin in the left- and
right-hand stubwings to detect heat damage, in accordance with the
Accomplishment Instructions of Fokker Service Bulletin SBF100-53-
087, dated November 17, 1997, at the latest of the times specified
in paragraphs (e)(1), (e)(2), and (e)(3) of this AD, as applicable.
Repeat the inspection required by paragraph (e) of this AD
thereafter at intervals not to exceed 6,000 landings.
(1) Within 6,000 landings after the effective date of this AD.
(2) Within 6 months after the effective date of this AD.
(3) Within 6,000 landings after accomplishment of the inspection
required by paragraph (a) of this AD.
(f) If any heat damage is detected during any inspection
required by paragraph (e) of this AD, prior to further flight,
perform a detailed visual inspection to determine the extent of heat
damage, in accordance with paragraph 2.B.(2) of the Accomplishment
Instructions of Fokker Service Bulletin SBF100-53-087, dated
November 17, 1997. Except as provided by paragraph (g) of this AD,
prior to further flight, repair in accordance with the service
bulletin.
Note 2: Fokker Service Bulletin SBF100-53-087, dated November
17, 1997, refers to Fokker Service Bulletin SBF100-53-084, dated
July 6, 1996, as an additional source of service information for the
detailed inspection procedures, repair limits, and repair
procedures.
(g) If any damage is found during accomplishment of any action
specified by paragraph (c)(1) or (f) of this AD, and Fokker Service
Bulletin SBF100-53-084, dated July 6, 1996, or Fokker Service
Bulletin SBF100-53-087, dated November 17, 1997, specifies to
contact the manufacturer for an appropriate action. Prior to further
flight, repair in accordance with a method approved by the Manager,
International Branch, ANM-116, FAA, Transport Airplane Directorate;
or the RLD (or its delegated agent).
(h) Installation of new heat shields, relocation of the aft bay
overheat switch, and replacement of the insulation blankets of the
bleed air ducts with new, improved insulation blankets, in
accordance with Fokker Proforma Service Bulletin SBF100-36-027,
including Appendix I, both dated March 21, 1997, constitutes
terminating action for the repetitive inspection requirements of
paragraph (e) of this AD.
(i)(1) 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.
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.
(i)(2) Alternative methods of compliance, approved previously in
accordance with AD 98-08-01, amendment 39-10450, are approved as
alternative methods of compliance with paragraphs (a), (b), and (c)
of this AD.
(i)(3) Airplanes repaired in accordance with alternative methods
of compliance, approved previously in accordance with AD 98-08-01,
are not considered exempt from the repetitive inspection
requirements of paragraph (e) of this AD.
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.
(j) 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 4: The subject of this AD is addressed in Dutch
airworthiness directive 1995-076/3 (A), dated November 28, 1997.
Issued in Renton, Washington, on November 3, 1998.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-30052 Filed 11-9-98; 8:45 am]
BILLING CODE 4910-13-P
