[Federal Register Volume 62, Number 62 (Tuesday, April 1, 1997)]
[Rules and Regulations]
[Pages 15375-15378]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-8248]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-CE-10-AD; Amendment 39-9985; AD 97-07-11]
Airworthiness Directives; Jetstream Aircraft Limited HP137 Mk1,
Jetstream Series 200, and Jetstream Models 3101 and 3201 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment supersedes Airworthiness Directive (AD) 81-20-
01, which currently requires repetitively inspecting the nose landing
gear (NLG) actuator support structure and the front pressure bulkhead
for cracks on Jetstream Aircraft Limited (JAL) HP137 Mk1 and Jetstream
series 200 airplanes, and replacing any cracked part. This AD retains
the repetitive inspections required by AD 81-20-01; requires
repetitively inspecting the NLG retraction jack upper mounting fitting
and attachment hardware for security bolt failure and for bolts with
improper torque levels on the HP137 Mk1, Jetstream series 200, and
Jetstream Model 3101 airplanes, and requires replacing any failed
security bolts and adjusting any bolt with an improper torque level;
and requires modifying the NLG retraction jack on all affected
airplanes, as terminating action for the repetitive inspections. This
AD results from reports of NLG jack mounting fitting failures on
several of the affected airplanes, and the Federal Aviation
Administration's policy on aging commuter-class aircraft. The actions
specified by this AD are intended to prevent failure of the NLG caused
by a cracked NLG actuator support structure or cracked front pressure
bulkhead, which, if not detected and corrected, could lead to nose gear
collapse and damage to the airplane.
DATES: Effective May 23, 1997.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of May 23, 1997.
ADDRESSES: Service information that applies to this AD may be obtained
from Jetstream Aircraft Limited, Prestwick International Airport,
Ayrshire, KA9 2RW, Scotland, telephone (44-292) 79888; facsimile (44-
292) 79703; or Jetstream Aircraft Inc., Librarian, P.O. Box 16029,
Dulles International Airport, Washington, D.C. 20041-6029; telephone
(703) 406-1161; facsimile (703) 406-1469. This information may also be
examined at the Federal Aviation Administration (FAA), Central Region,
Office of the Assistant Chief Counsel, Attention: Rules Docket No. 95-
CE-10-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106;
or at the Office of the Federal Register, 800 North Capitol Street,
NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Mr. Tom Rodriguez, Program Manager,
Brussels Aircraft Certification Division, FAA, Europe, Africa, and
Middle East Office, c/o American Embassy, B-1000 Brussels, Belgium;
telephone (32 2) 508.2715; facsimile (32 2) 230.6899; or Mr. S.M.
Nagarajan, Project Officer, Small Airplane Directorate, Aircraft
Certification Service, FAA, 1201 Walnut, suite 900, Kansas City,
Missouri 64106; telephone (816) 426-6932; facsimile (816) 426-2169.
SUPPLEMENTARY INFORMATION:
Events Leading to the Issuance of This AD
A proposal to amend part 39 of the Federal Aviation Regulations (14
CFR part 39) to include an AD that would apply to certain JAL HP137
Mk1, Jetstream series 200, and Jetstream Models 3101 and 3201 airplanes
that do not have an improved design attachment bracket (Modification JM
5285) installed for the nose landing gear (NLG) retraction jack was
published in the Federal Register as a notice of proposed rulemaking
(NPRM) on September 19, 1995 (60 FR 48429). The NPRM proposed to
supersede AD 81-20-01 with a new AD that would:
--Retain the requirement contained in AD 81-20-01 of repetitively
inspecting (using dye penetrant methods) the NLG actuator support
structure and the front pressure bulkhead for cracks on JAL HP137 Mk1
and Jetstream series 200 airplanes that do not have the front pressure
bulkhead strengthened in the area of the NLG jack attachment fitting
(Modification No. 5127), and replacing or repairing any cracked NLG
actuator support structure or cracked front pressure bulkhead.
Accomplishment of the proposed inspections as specified in the NPRM
would be in accordance with Jetstream Service Bulletin (SB) No. 6/5,
dated September 4, 1978.
--Require repetitively inspecting the NLG retraction jack upper
mounting fitting and attachment hardware for security bolt failure and
bolts with improper torque levels on the HP137 Mk1, Jetstream series
200, and Jetstream Model 3101 airplanes, and replacing any failed
security bolts and adjusting any bolt with an improper torque level.
Accomplishment of the proposed inspections as specified in the NPRM
would be in accordance with Jetstream SB 53-A-JA870510, which consists
of the following pages and revision levels:
------------------------------------------------------------------------
Pages Revision level Date
------------------------------------------------------------------------
3, 5, 6, 8, 9, and 10........... Original Issue.... May 26, 1987.
1, 2, 4 and 7................... Revision 1........ Nov. 10, 1987.
------------------------------------------------------------------------
--Require modifying the NLG retraction jack on the HP137 Mk1, Jetstream
series 200, and Jetstream Models 3101 and 3201 airplanes, as
terminating action for all the repetitive inspections, including the
inspections referenced in the Model 3201 maintenance manual.
Accomplishment of the proposed modification as specified in the NPRM
would be in accordance with Jetstream SB 53-JM 5285, which consists of
the following pages and revision levels:
------------------------------------------------------------------------
Pages Revision level Date
------------------------------------------------------------------------
1 and 4......................... Revision 2........ Nov. 12, 1992.
2, 3, and 5 through 26.......... Revision 1........ May 18, 1992.
------------------------------------------------------------------------
Interested persons have been afforded an opportunity to participate
in the making of this amendment. One comment was received regarding the
NPRM. An analysis of the comment follows:
The commenter provides information on the company's fleet size and
the estimated projection on when the proposed replacement would be
mandatory on the affected airplanes in the company's fleet, as well as
the number of repetitive inspections that would be required during that
time. The commenter states that it is more economical for the company
to incorporate the modification on its entire fleet immediately rather
than continuing to repetitively inspect. The commenter also mentions
that parts to
[[Page 15376]]
modify the NLG retraction jack cost $1,800 instead of $1,600. The FAA
concurs with the correction to the cost and has incorporated this
change.
As written, the original NPRM would have allowed continued flight
if cracks are found in the front pressure bulkhead membrane or actuator
support structure when the cracks do not exceed certain limits. Since
issuing that NPRM, the FAA established a policy to disallow airplane
operation when known cracks exist in primary structure, unless the
ability to sustain ultimate load with these cracks is proven. The front
pressure bulkhead and actuator support structure are considered primary
structure, and the FAA has not received any analysis to prove that
ultimate load can be sustained with cracks in this area.
For this reason, the FAA has determined that the crack limits
contained in the NPRM should be eliminated and that AD action should be
taken to require immediate replacement of any cracked front pressure
bulkhead membrane or actuator support structure. Since revising the
proposed AD to require immediate replacement of any cracked part went
beyond the scope of what was presented in the original NPRM, the FAA
published a supplemental NPRM in the Federal Register on October 21,
1996 (61 FR 54582), in order to give the public an opportunity to
comment on the proposal.
Interested persons were again afforded an opportunity to
participate in the making of this amendment. No comments were received
regarding the substance of the supplemental NPRM or the FAA's
determination of the cost to the public.
The FAA's Determination
After careful review of all available information related to the
subject presented above, the FAA has determined that air safety and the
public interest require the adoption of the AD as proposed except for
minor editorial corrections. The FAA has determined that these minor
corrections will not change the meaning of the AD and will not add any
additional burden upon the public than was already proposed.
The FAA's Aging Commuter Aircraft Policy
The actions required by this AD are consistent with the FAA's aging
commuter aircraft policy, which briefly states that, when a
modification exists that could eliminate or reduce the number of
required critical inspections, the modification should be incorporated.
This policy is based on the FAA's determination that reliance on
critical repetitive inspections on airplanes utilized in commuter
service carries an unnecessary safety risk when a design change exists
that could eliminate or, in certain instances, reduce the number of
those critical inspections. In determining what inspections are
critical, the FAA considers (1) the safety consequences of the airplane
if the known problem is not detected by the inspection; (2) the
reliability of the inspection such as the probability of not detecting
the known problem; (3) whether the inspection area is difficult to
access; and (4) the possibility of damage to an adjacent structure as a
result of the problem.
Cost Impact
The FAA estimates that 170 airplanes in the U.S. registry will be
affected by this AD, that it will take approximately 41 workhours per
airplane to accomplish the proposed modification, and that the average
labor rate is approximately $60 an hour. Parts cost approximately
$1,800 per airplane. Based on these figures, the total cost impact of
this AD on U.S. operators is estimated to be $724,200 or $4,260 per
airplane. This figure only takes into account the cost of the
inspection-terminating modification and does not take into account the
cost of the repetitive inspections. The FAA has no way of determining
the number of repetitive inspections each HP137 Mk1, Jetstream series
200, and Jetstream Model 3101 airplane owner/operator will incur over
the life of the airplane.
This figure is also based on the presumption that no affected
airplane owner/operator has accomplished the required modification.
This AD eliminates the need for the repetitive inspections required by
AD 81-20-01. The FAA has no way of determining the operational levels
of each individual operator of the affected airplanes, and subsequently
cannot determine the repetitive inspection costs that will be
eliminated by this AD. The FAA estimates these costs to be substantial
over the long term.
In addition, JAL has informed the FAA that parts have been
distributed to owners/operators to equip approximately 39 of the
affected airplanes. Presuming that each set of parts has been installed
on an affected airplane, the cost impact of the required modification
upon the public is reduced $166,140 from $724,200 to $558,060.
The intent of the FAA's aging commuter airplane program is to
ensure safe operation of airplanes that are in commercial service
without adversely impacting private operators. Of the approximately 170
airplanes in the U.S. registry that will be affected by this AD, the
FAA has determined that approximately 95 percent are operated in
scheduled passenger service by 10 different operators.
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 copy of the final 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, 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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing Airworthiness Directive
(AD) 81-20-01, Amendment 39-4223, and by adding a new AD to read as
follows:
97-07-11 Jetstream Aircraft Limited: Amendment 39-9985; Docket No.
95-CE-10-AD. Supersedes AD 81-20-01, Amendment 39-4223.
Applicability: The following airplanes, certificated in any
category, that do not have
[[Page 15377]]
an improved design attachment bracket for the nose landing gear
(NLG) retraction jack (Modification JM 5285) installed in accordance
with the ACCOMPLISHMENT INSTRUCTIONS section of Jetstream Service
Bulletin (SB) 53-JM 5285:
--HP137 Mk1 airplanes, all serial numbers;
--Jetstream Series 200 airplanes, all serial numbers;
--Jetstream Model 3101 airplanes, all serial numbers; and
--Jetstream Model 3201 airplanes, serial numbers 601 through 840.
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 in the body of this AD, unless
already accomplished.
To prevent failure of the NLG caused by a cracked NLG actuator
support structure or cracked front pressure bulkhead, which could
lead to nose gear collapse and damage to the airplane, accomplish
the following:
Note 2: The paragraph structure of this AD is as follows:
Level 1: (a), (b), (c), etc.
Level 2: (1), (2), (3), etc.
Level 3: (i), (ii), (iii), etc.
Level 2 and Level 3 structures are designations of the Level 1
paragraph they immediately follow.
(a) For HP137 Mk1 and Jetstream series 200 airplanes that do not
have the front pressure bulkhead strengthened in the area of the NLG
jack attachment fitting (Modification 5127), upon accumulating 1,600
landings or within the next 200 landings after the effective date of
this AD, whichever occurs later, and thereafter at intervals not to
exceed 200 landings until the modification required by paragraph (c)
of this AD is incorporated, inspect (using dye penetrant methods)
the nose landing gear actuator support structure, part number (P/N)
137139C-13 and P/N 137139C-25 (or FAA-approved equivalents), and the
membrane of the front pressure bulkhead for cracks. Accomplish the
inspection in accordance with British Aerospace (BAe) SB No. 6/5,
dated September 4, 1978.
(1) Prior to further flight after any of the inspections
required by paragraph (a) of this AD, replace any cracked P/N
137139C-13 (or FAA-approved equivalent) NLG actuator support
structure. This replacement does not eliminate the repetitive
inspection requirement of this AD.
(2) Prior to further flight after any of the inspections
required by paragraph (a) of this AD, repair any cracked P/N
137139C-25 (or FAA-approved equivalent) NLG actuator support
structure in accordance with the applicable maintenance manual. This
repair does not eliminate the repetitive inspection requirement of
this AD.
(3) Prior to further flight after any of the inspections
required by paragraph (a) of this AD, repair any cracked front
pressure bulkhead membrane in accordance with the applicable
maintenance manual. This repair does not eliminate the repetitive
inspection requirement of this AD.
(b) For all HP137 Mk1, Jetstream series 200, and Jetstream Model
3101 airplanes, upon accumulating 3,500 landings or within the next
200 landings after the effective date of this AD, whichever occurs
later, accomplish the following:
(1) Inspect the NLG retraction jack upper mounting fitting and
attaching hardware for correct installation, security bolt failure,
and bolts with improper torque levels in accordance with Part A and
B of the ACCOMPLISHMENT INSTRUCTIONS section of Jetstream SB 53-A-
JA870510, which incorporates the following pages and revision
levels:
------------------------------------------------------------------------
Pages Revision level Date
------------------------------------------------------------------------
3, 5, 6, 8, 9, and 10........... Original Issue.... May 26, 1987.
1, 2, 4 and 7................... Revision 1........ November 10, 1987.
------------------------------------------------------------------------
Prior to further flight, replace any failed security bolt and adjust
any bolt with an improper torque level in accordance with Jetstream
SB 53-A-JA870510.
(2) Reinspect the NLG retraction jack upper mounting fitting and
attaching hardware for security bolt failure and bolts with improper
torque levels in accordance with Part A of the ACCOMPLISHMENT
INSTRUCTIONS section of Jetstream SB 53-A-JA870510 at intervals not
to exceed 1,600 landings until the modification required by
paragraph (c) of this AD is incorporated. Prior to further flight,
replace any failed security bolt and adjust any bolt with an
improper torque level in accordance with Jetstream SB 53-A-JA870510.
(3) Reinspect the NLG retraction jack upper mounting fitting
security nuts for correct installation in accordance with Part B of
the ACCOMPLISHMENT INSTRUCTIONS section of Jetstream SB 53-A-
JA870510 at intervals not to exceed 200 landings until the
modification required by paragraph (c) of this AD is incorporated.
If correct installation is not evident, prior to further flight,
accomplish the reinspection specified in paragraph (b)(2) of this
AD.
(c) For all applicable HP137 Mk1, Jetstream series 200, and
Jetstream Models 3101 and 3201 airplanes, upon accumulating 25,000
landings or within the next 2,000 landings after the effective date
of this AD, whichever occurs later, install an improved design
attachment bracket for the NLG retraction jack (Modification JM
5285) in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of
Jetstream SB 53-JM 5285, which incorporates the following pages and
revision levels:
------------------------------------------------------------------------
Pages Revision level Date
------------------------------------------------------------------------
1 and 4......................... Revision 2........ November 12, 1992.
2, 3, and 5 through 26.......... Revision 1........ May 18, 1992.
------------------------------------------------------------------------
(1) Incorporating Modification JM 5285 on Jetstream HP137 Mk1,
Jetstream series 200, and Jetstream Model 3101 airplanes terminates
the repetitive inspection requirement of this AD.
(2) Incorporating Modification JM 5285 on Jetstream Model 3201
airplanes eliminates the need for the repetitive inspections
specified in the applicable maintenance manual.
(3) Modification JM 5285 may be accomplished at any time prior
to accumulating 25,000 landings or within the next 2,000 landings
after the effective date of this AD, whichever occurs later, at
which time it must be incorporated.
(d) 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.
(e) An alternative method of compliance or adjustment of the
initial or repetitive compliance times that provides an equivalent
level of safety may be approved by the Manager, Brussels Aircraft
Certification Division, Europe, Africa, Middle East office, FAA, c/o
American Embassy, 1000 Brussels, Belgium. The request should be
forwarded through an appropriate FAA Maintenance Inspector, who may
add comments and then send it to the Manager, Brussels Aircraft
Certification Division. Alternative methods of compliance approved
in accordance with AD 81-20-01 (superseded by this action) are not
considered approved as alternative methods of compliance with this
AD.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Brussels Aircraft Certification Division.
(f) The NLG actuator support structure inspections required by
this AD shall be done in accordance with British Aerospace (BAe)
Service Bulletin No. 6/5, dated September 4, 1978. The inspection of
the NLG retraction jack upper mounting fitting and attaching
hardware required by this AD shall be done in accordance with
Jetstream Service Bulletin 53-A-JA870510, which incorporates the
following pages and revision levels:
------------------------------------------------------------------------
Pages Revision level Date
------------------------------------------------------------------------
3, 5, 6, 8, 9, and 10........... Original Issue.... May 26, 1987.
1, 2, 4 and 7................... Revision 1........ Nov. 10, 1987.
------------------------------------------------------------------------
The installation required by this AD shall be accomplished in
accordance with Jetstream SB 53-JM 5285, which incorporates the
following pages and revision levels:
[[Page 15378]]
------------------------------------------------------------------------
Pages Revision level Date
------------------------------------------------------------------------
1 and 4......................... Revision 2........ November 12, 1992.
2, 3, and 5 through 26.......... Revision 1........ May 18, 1992.
------------------------------------------------------------------------
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 Jetstream Aircraft Limited, Manager
Product Support, Prestwick Airport, Ayrshire, KA9 2RW Scotland; or
Jetstream Aircraft Inc., Librarian, P.O. Box 16029, Dulles
International Airport, Washington, DC, 20041-6029. Copies may be
inspected at the FAA, Central Region, Office of the Assistant Chief
Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at
the Office of the Federal Register, 800 North Capitol Street, NW.,
suite 700, Washington, DC.
(g) This amendment (39-9985) becomes effective on
May 23, 1997.
Issued in Kansas City, Missouri, on March 26, 1997.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 97-8248 Filed 3-31-97; 8:45 am]
BILLING CODE 4910-13-U
