[Federal Register Volume 61, Number 57 (Friday, March 22, 1996)]
[Proposed Rules]
[Pages 11786-11789]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-6881]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-CE-94-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) 87-07-01, which currently requires the following on Jetstream
Aircraft Limited (JAL) HP137 Mk1, Jetstream series 200, and Jetstream
Model 3101 airplanes: repetitively inspecting the nose landing gear
(NLG) top cap assembly securing bolts for looseness or cracks,
retorquing any loose security bolt, and replacing any cracked security
bolt. AD 87-07-01 also provides the option of incorporating a NLG
modification as terminating action for the repetitive inspections. A
report of cracked and loose bolts found on an airplane with the above-
referenced NLG modification prompted the proposed action. The proposed
action would: retain the repetitive inspections required by AD 87-07-
01; increase the AD applicability to include Jetstream Model 3201
airplanes and airplanes that have the NLG top cap assembly modified in
accordance with AD 87-07-01; require replacing two of the NLG top cap
assembly securing bolts; and incorporate a new NLG top cap assembly
that would eliminate the repetitive inspection requirement of the AD.
The actions specified in the proposed AD are intended to prevent
failure of the NLG caused by cracked or loose securing bolts, which, if
not detected and corrected, could lead to NLG collapse and damage to
the airplane.
DATES: Comments must be received on or before May 24, 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-94-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, 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. Jeffrey Morfitt,
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-94-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-94-AD, Room 1558, 601 E. 12th Street,
Kansas City, Missouri 64106.
Discussion
AD 87-07-01, Amendment 39-5582, currently requires the following on
Jetstream Aircraft Limited (JAL) HP137 Mk1, Jetstream series 200, and
Jetstream Model 3101 airplanes: repetitively inspecting the nose
landing gear (NLG) top cap assembly securing bolts for looseness or
cracks, retorquing any loose security bolt, and replacing any cracked
security bolt. This AD also provides the option of replacing the
existing top cap assembly and bolts with parts of improved design.
The FAA has received a report of NLG top cap assembly failure on a
Jetstream airplane where the existing top cap assembly and bolts were
replaced with parts of improved design in accordance with AD 87-07-01.
In addition, JAL has re-evaluated the instructions and the design of
the improved NLG top cap assembly specified in AD 87-07-01, and
determined that airplanes that have the NLG top cap assembly design
installed as specified in AD 87-07-01 could experience NLG failure
caused by cracked or loose securing bolts.
The JAL Jetstream Model 3201 airplanes were not included in AD 87-
07-01 because they had NLG top cap assemblies and bolts of improved
design incorporated at manufacture. These NLG top cap assemblies and
bolts are of design identical to that referenced in the incident report
described above and to that of the assemblies referenced as terminating
action for the repetitive inspection requirement of AD 87-07-01.
JAL has designed a new NLG top cap assembly bolt that, when
incorporated, would reduce the possibility of loose or cracked securing
bolts and subsequent NLG failure. Jetstream Service Bulletin (SB) 32-JA
901040, Revision No. 3, dated August 9, 1995, specifies procedures for:
--Checking the torque levels of the NLG top cap assembly securing
bolts;
--Replacing two of the NLG top cap assembly securing bolts and checking
the length of the NLG top cap assembly securing bolts; and
--Installing a new modified top cap assembly.
Jetstream SB 32-JA 901040 also references NLG top cap installation
[[Page 11787]]
procedures that are included in AP Precision Hydraulics Ltd SB 32-41,
which incorporates the following pages:
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Pages Revision level Date
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1, 2, 6, 7, 8 and 15................... Revision No. 2..................... March 9, 1993.
4 and 10............................... Revision No. 1..................... July 11, 1991.
3, 5, 9, 11, 12, 13, and 14............ Original Issue..................... November 17, 1990.
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The FAA has reviewed all available information related to the
incident described above, including the referenced service bulletins,
and has determined that AD action should be taken to prevent failure of
the NLG caused by cracked or loose securing bolts, which, if not
detected and corrected, could lead to NLG collapse and damage to the
airplane.
AD 87-07-01 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 incident 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 a modified NLG top cap assembly incorporated (Amendment JA
901040) in accordance with Jetstream SB 32-JA 901040, Revision 3, dated
August 9, 1995, the proposed AD would supersede AD 87-07-01 with a new
AD that would:
--Retain the requirement contained in AD 87-07-01 of repetitively
inspecting the NLG top cap assembly securing bolts for looseness,
retorquing any loose security bolt, and replacing any cracked security
bolt;
--Require replacing two of the NLG top cap assembly securing bolts and
checking the other two NLG top cap assembly securing bolts for the
correct length; and
--Require replacing (at a specified time) the NLG top cap assembly with
a part of improved design (Amendment JA 901040) as terminating action
for the repetitive inspections.
Accomplishment of the proposed actions would be in accordance with
Jetstream SB 32-JA 901040, Revision No. 3, and AP Precision Hydraulics
SB 32-41.
The FAA estimates that 150 airplanes in the U.S. registry would be
affected by the proposed AD, that it would take approximately 18
workhours (inspection: 6 workhours; replacement: 12 workhours) to
accomplish the proposed actions, and that the average labor rate is
approximately $60 an hour. Parts cost approximately $1,200 per
airplane. Based on these figures, the total cost impact of the proposed
AD on U.S. operators is estimated to be $342,000 or $2,280 per
airplane. This figure only takes into account the cost of the proposed
initial inspection and 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 of the owners/operators would incur over the life of
the affected airplanes.
This figure is also based on the assumption that none of the
affected airplane owners/operators have accomplished the proposed
modification. This action would eliminate the repetitive inspections
required by AD 87-07-01. 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 62 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 $141,360 from $342,000 to $200,640.
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 150 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 10 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
[[Page 11788]]
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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing Airworthiness Directive
(AD) 87-07-01, Amendment 39-5582, and adding a new AD to read as
follows:
Jetstream Aircraft Limited: Docket No. 95-CE-94-AD. Supersedes AD
87-07-01, Amendment 39-5582.
Applicability: The following airplane models and serial numbers,
certificated in any category, that do not have a modified nose
landing gear (NLG) top cap assembly incorporated (Amendment JA
901040) in accordance with Jetstream Service Bulletin (SB) 32-JA
901040, Revision No. 3, dated August 9, 1995:
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Model Serial Numbers
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HP137 Mk1................................. All serial numbers;
Jetstream series 200...................... All serial numbers;
Jetstream Model 3101...................... All serial numbers; and
Jetstream Model 3201...................... Serial numbers 790 through
854.
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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 (f) 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 cracked or loose
securing bolts, which, if not detected and corrected, could lead to
NLG 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) Within the next 300 landings accumulated on the NLG after
the effective date of this AD, accomplish the following in
accordance with the applicable portion of the ACCOMPLISHMENT
INSTRUCTIONS section of Jetstream SB 32-JA 901040, Revision No. 3,
dated August 9, 1995, and AP Precision Hydraulics Ltd SB 32-41,
which incorporates the following pages:
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Pages Revision level Date
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1, 2, 6, 7, 8 and 15................... Revision No. 2..................... March 9, 1993.
4 and 10............................... Revision No. 1..................... July 11, 1991.
3, 5, 9, 11, 12, 13, and 14............ Original Issue..................... November 17, 1990.
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(1) Replace two of the NLG top cap assembly securing bolts, and
check the other two for correct length in accordance with part 1A of
the ACCOMPLISHMENT INSTRUCTIONS section of AP Precision Hydraulics
Ltd SB 32-41. Prior to further flight, replace any NLG top securing
bolt that is not the length specified in AP Precision Hydraulics Ltd
SB 32-41.
(2) Check the tightness of the four NLG top cap assembly
securing bolts and ensure that these bolts are not broken in
accordance with part 1b of the ACCOMPLISHMENT INSTRUCTIONS section
of AP Precision Hydraulics Ltd SB 32-41.
(i) Prior to further flight, retorque any bolts with incorrect
torque values.
(ii) If any bolts are broken or gaps are found as specified in
paragraph A.(4) of part 1b of the ACCOMPLISHMENT INSTRUCTIONS
section of AP Precision Hydraulics Ltd SB 32-41, prior to further
flight, replace the NLG in accordance with the applicable
maintenance manual.
(b) Within 1,200 landings after the actions required by
paragraph (a) of this AD (all paragraph designations), and
thereafter at intervals not to exceed 1,200 landings, until the
modification required by paragraph (c) of this AD is incorporated,
check the tightness of the four NLG top cap assembly securing bolts
and ensure that these bolts are not broken in accordance with part
1b of the ACCOMPLISHMENT INSTRUCTIONS section of AP Precision
Hydraulics Ltd SB 32-41.
(1) Prior to further flight, retorque any bolts with incorrect
torque values.
(2) If any bolts are broken or gaps are found as specified in
paragraph A.(4) of part 1b of the ACCOMPLISHMENT INSTRUCTIONS
section of AP Precision Hydraulics Ltd SB 32-41, prior to further
flight, replace the NLG in accordance with the applicable
maintenance manual.
(c) Upon accumulating 20,000 landings on the NLG or within the
next 2,500 landings accumulated on the NLG after the effective date
of this AD, whichever occurs later, install a new NLG top cap
assembly or modify the existing NLG top cap assembly in accordance
with Part 2 of the ACCOMPLISHMENT INSTRUCTIONS section of AP
Precision Hydraulics Ltd SB 32-41, which incorporates the following
pages:
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Pages Revision level Date
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1, 2, 6, 7, 8 and 15................... Revision No. 2..................... March 9, 1993.
4 and 10............................... Revision No. 1..................... July 11, 1991.
3, 5, 9, 11, 12, 13, and 14............ Original Issue..................... November 17, 1990.
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(d) Incorporating the modification required by paragraph (c) of
this AD is considered terminating action for the repetitive torque
checks required by this AD and may be incorporated at any time prior
to 20,000 landings on a NLG or within the next 2,500 landings
accumulated on the NLG after the effective date of this AD,
whichever occurs later (at which time it must be incorporated).
(e) 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.
(f) 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 (ACO), 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 ACO.
Note 3: Information concerning the existence of approved
alternative methods of
[[Page 11789]]
compliance with this AD, if any, may be obtained from the Brussels
ACO.
Note 4: Alternative methods of compliance approved in accordance
with AD 87-07-01 (superseded by this action) are not considered
approved as alternative methods of compliance with this AD.
(g) 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.
(h) This amendment supersedes AD 87-07-01, Amendment 39-5582.
Issued in Kansas City, Missouri, on March 14, 1996.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-6881 Filed 3-21-96; 8:45 am]
BILLING CODE 4910-13-P
