[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]



-----------------------------------------------------------------------


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).

-----------------------------------------------------------------------

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:

----------------------------------------------------------------------------------------------------------------
                 Pages                              Revision level                           Date               
----------------------------------------------------------------------------------------------------------------
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.                
----------------------------------------------------------------------------------------------------------------

    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:

------------------------------------------------------------------------
                   Model                           Serial Numbers       
------------------------------------------------------------------------
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.                       
------------------------------------------------------------------------

    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:

----------------------------------------------------------------------------------------------------------------
                 Pages                              Revision level                           Date               
----------------------------------------------------------------------------------------------------------------
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.                
----------------------------------------------------------------------------------------------------------------

    (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:

----------------------------------------------------------------------------------------------------------------
                 Pages                              Revision level                           Date               
----------------------------------------------------------------------------------------------------------------
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.                
----------------------------------------------------------------------------------------------------------------

    (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