[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:

------------------------------------------------------------------------
              Pages                 Revision level           Date       
------------------------------------------------------------------------
1 and 4.........................  Revision 2........  November 12, 1992.
2, 3, and 5 through 26..........  Revision 1........  May 18, 1992.     
------------------------------------------------------------------------

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