[Federal Register Volume 60, Number 228 (Tuesday, November 28, 1995)]
[Proposed Rules]
[Pages 58586-58589]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-29050]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-CE-10-AD]
Airworthiness Directives; Jetstream Aircraft Limited HP137 Mk1,
Jetstream Series 200, and Jetstream Models 3101 and 3201 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes to supersede 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.
The proposed action would: retain the repetitive inspections required
by AD 81-20-01; require 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 require
replacing any failed security bolts and adjusting any bolt with an
improper torque level; and require modifying the NLG retraction jack on
all affected airplanes as terminating action for the repetitive
inspections. The proposed action is prompted by reports of NLG jack
mounting fitting failures on several of the affected airplanes, and by
the Federal Aviation Administration's policy on aging commuter-class
aircraft. The actions specified in the proposed 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: Comments must be received on or before February 9, 1996.
ADDRESSES: Submit comments on the proposal in triplicate to 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. Comments may be inspected
at this location between 8 a.m. and 4 p.m., Monday through Friday,
holidays excepted.
Service information that applies to the proposed AD may be obtained
from Jetstream Aircraft Limited, Manager Product Support, Prestwick
Airport,
[[Page 58587]]
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, DC 20041-6029; telephone
(703) 406-1161; facsimile (703) 406-1469. This information also may be
examined at the Rules Docket at the address above.
FOR FURTHER INFORMATION CONTACT: Ms. Dorenda Baker, Program Officer,
Brussels Aircraft Certification Office, FAA, Europe, Africa, and Middle
East Office, c/o American Embassy, B-1000 Brussels, Belgium; telephone
(322) 508-2715; facsimile (322) 230-6899; or Mr. Sam Lovell, Project
Officer, Small Airplane Directorate, Airplane Certification Service,
FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106; telephone
(816) 426-6932; facsimile (816) 426-2169.
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 should 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 that summarizes 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 No. 95-CE-10-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, 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.
Discussion
The FAA has received several reports of loose or failed bolts that
attach the nose landing gear (NLG) jack mounting fitting to the front
pressure bulkhead on JAL HP137 Mk1, Jetstream series 200, and Jetstream
Model 3101 airplanes. In addition, JAL and the FAA have found similar
failures during testing of fatigue test articles of this type design.
JAL has introduced Modification JM 5285, which consists of an
attachment bracket of improved design for the NLG retraction jack.
Procedures for accomplishing Modification JM 5285 are included within
Jetstream Service Bulletin (SB) 53-JM 5285, which consists of the
following pages and revision levels:
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Pages Revision level Date
------------------------------------------------------------------------
1 and 4......................... Revision 2........ November 12, 1992.
2, 3, and 5 through 26.......... Revision 1........ May 18, 1992.
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In addition, JAL has issued Jetstream SB 53-A-JA870510, which specifies
procedures for inspecting the NLG retraction jack upper mounting
fitting security bolts. Jetstream SB 53-A-JA870510 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.
------------------------------------------------------------------------
The FAA has reviewed all available information related to the
incidents described above including the referenced service bulletins
and has determined that AD action should be taken 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.
In addition, AD 81-20-01, Amendment 39-4223, currently requires the
following 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): repetitively
inspecting (using dye penetrant methods) the NLG actuator support
structure and the front pressure bulkhead for cracks, and replacing or
repairing any cracked NLG actuator support structure or cracked front
pressure bulkhead. The inspections required by AD 81-20-01 are
accomplished in accordance with Jetstream SB No. 6/5, dated September
4, 1978.
AD 81-20-01 has been identified as one that should be superseded
under the FAA's aging commuter-class airplane policy. The FAA has
determined that reliance on critical repetitive inspections on aging
commuter-class airplanes 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
if the known problem is not detected during the inspection; (2) the
probability of the problem not being detected during the inspection;
(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.
Based on these factors, the FAA established this aging commuter-
class aircraft policy to require the incorporation of a known design
change when it could eliminate or, in certain instances, reduce the
number of critical repetitive inspections.
The FAA is combining this policy with the incidents presented in
this discussion to establish the basis for the proposed AD action.
Since an unsafe condition has been identified that is likely to
exist or develop in other JAL HP137 Mk1, Jetstream series 200, and
Jetstream Models 3101 and 3201 airplanes of the same type design that
do not have Modification JM 5285 incorporated, the proposed AD would
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 without Modification 5127
incorporated, and replacing or repairing any cracked NLG actuator
support structure or cracked front pressure bulkhead. Accomplishment of
these proposed inspections would continue to be accomplished in
accordance with Jetstream 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
[[Page 58588]]
Jetstream Model 3101 airplanes, and replacing any failed security bolts
and adjusting any bolt with an improper torque level. Accomplishment of
these proposed inspections would be in accordance with Jetstream SB 53-
A-JA870510.
--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 this
proposed modification would be in accordance with Jetstream SB 53-JM
5285.
The FAA estimates that 170 airplanes in the U.S. registry would be
affected by the proposed AD, that it would take approximately 41
workhours to accomplish the proposed modification, and that the average
labor rate is approximately $60 an hour. Parts cost approximately
$1,600 per airplane. Based on these figures, the total cost impact of
the proposed AD on U.S. operators is estimated to be $690,200 or $4,060
per airplane. This figure only takes into account the cost of the
proposed inspection-terminating modification and does not take into
account the cost of the proposed 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 would incur.
This figure is also based on the assumption that none of the
affected airplane operators have accomplished the proposed
modification. This action would eliminate the repetitive inspections
required by AD 81-20-01. The FAA has no way of determining the
operation levels of each individual operator of the affected airplanes,
and subsequently cannot determine the repetitive inspection costs that
would be eliminated by the proposed action. 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 that would equip approximately 39 of
the affected airplanes. Assuming that these parts have been installed
on the affected airplanes, the cost impact of the proposed modification
upon the public would be reduced $158,340 from $690,200 to $531,860.
The intent of the FAA's aging commuter airplane program is to
ensure safe operation of commuter-class airplanes that are in
commercial service without adversely impacting private operators. Of
the approximately 170 airplanes in the U.S. registry that would be
affected by the proposed AD, the FAA has determined that approximately
95 percent are operated in scheduled passenger service by 14 different
operators.
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 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) 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 has been placed 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), 40101, 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing Airworthiness Directive
(AD) 81-20-01, Amendment 39-4223, and adding a new AD to read as
follows:
Jetstream Aircraft Limited: 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 Modification JM 5285 incorporated:
--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 nose landing gear (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, 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, and the membrane of the front
pressure bulkhead for cracks. Accomplish the inspection in
accordance with British Aerospace (BAe) Service Bulletin (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 NLG actuator support structure.
(2) Prior to further flight after any of the inspections
required by paragraph (a) of this AD, repair in accordance with the
maintenance manual any P/N 137139C-25 NLG actuator support structure
where cracking is found that extends more than half the full length
of the fold line.
(3) Prior to further flight after any of the inspections
required by paragraph (a) of this AD, repair in accordance with the
maintenance manual any front pressure
[[Page 58589]]
bulkhead membrane that has a crack with a length of six inches or more.
(4) If a crack less than 6 inches in length is found in the
front pressure bulkhead membrane during any of the inspections
required by paragraph (a) of this AD, prior to further flight,
accomplish one of the following:
(i) Repair the front pressure bulkhead membrane in accordance
with the applicable maintenance manual.
(ii) Fabricate a placard with the words ``Pressurization
Inoperative'' in \1/8\-inch letters, and install this placard in the
airplane cabin within the pilot's clear view. Deactivate the cabin
pressurization system by securing the safety valve assembly to the
open position. This system is located on the front pressure
bulkhead.
(iii) 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.
------------------------------------------------------------------------
The repetitive inspections required by this AD are no longer
required after incorporating Modification JM 5285.
(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, 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 Office, 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 Office.
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 Office.
Note 4: 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.
(f) All persons affected by this directive may obtain copies of
the document referred to herein upon request to 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; or may examine this
document at the FAA, Central Region, Office of the Assistant Chief
Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.
(g) This amendment supersedes AD 81-20-01, Amendment 39-4223.
Issued in Kansas City, Missouri, on November 20, 1995.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 95-29050 Filed 11-27-95; 8:45 am]
BILLING CODE 4910-13-U
