[Federal Register Volume 61, Number 204 (Monday, October 21, 1996)]
[Proposed Rules]
[Pages 54582-54585]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-26861]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 61, No. 204 / Monday, October 21, 1996 / 
Proposed Rules  

[[Page 54582]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-CE-10-AD]
RIN 2120-AA64


Airworthiness Directives; Jetstream Aircraft Limited HP137 Mk1, 
Jetstream Series 200, and Jetstream Models 3101 and 3201 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
the comment period.

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

SUMMARY: This document proposes to revise an earlier proposed 
airworthiness directive (AD), which would have superseded AD 81-20-01. 
That AD 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 previous 
document would have: retained the repetitive inspections required by AD 
81-20-01; required 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; required 
replacing any failed security bolts and adjusting any bolt with an 
improper torque level; and required modifying the NLG retraction jack 
on all affected airplanes as terminating action for the repetitive 
inspections. As currently written, the document allows continued flight 
if cracks are found in the front pressure bulkhead membrane and 
actuator support structure when cracks do not exceed certain limits. 
Since publication of that proposal, the Federal Aviation Administration 
(FAA) has established a policy to disallow airplane operation when 
known cracks exist in primary structure (the affected airplane parts 
are considered primary structure). The actions specified by 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 could lead to nose gear collapse and damage to the 
airplane. Since the comment period for the original proposal has closed 
and the change described above goes beyond the scope of what was 
originally proposed, the FAA is allowing additional time for the public 
to comment.

DATES: Comments must be received on or before December 27, 1996.

ADDRESSES: Submit comments in triplicate 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. 
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, Prestwick International Airport, 
Ayrshire, KA9 2RW, Scotland, telephone (44-292) 79888; facsimile (44-
292) 79703; or Jetstream Aircraft Inc., Librarian, P.O. Box 16029, 
Dulles International Airport, Washington, D.C. 20041-6029; telephone 
(703) 406-1161; facsimile (703) 406-1469. This information also may be 
examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Tom Rodriguez, Program Manager, 
Brussels Aircraft Certification Division, FAA, Europe, Africa, and 
Middle East Office, c/o American Embassy, B-1000 Brussels, Belgium; 
telephone (32 2) 508.2717; facsimile (32 2) 230.6899; or Mr. Larry D. 
Malir, Project Officer, Small Airplane Directorate, Aircraft 
Certification Service, FAA, 1201 Walnut, suite 900, Kansas City, 
Missouri 64106; telephone (816) 426-6932; facsimile (816) 426-2169.

SUPPLEMENTARY INFORMATION:

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 Supplemental NPRM

    Any person may obtain a copy of this supplemental 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

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to include an AD that would apply to certain JAL HP137 
Mk1, Jetstream series 200, and Jetstream Models 3101 and 3201 airplanes 
that do not have an improved design attachment bracket (Modification JM 
5285) installed for the nose landing gear (NLG) retraction jack was 
published in the Federal Register on September 19, 1995 (60 FR 48429). 
The action proposed to supersede AD 81-20-01 with a new AD that would:

--Retain the requirement contained in AD 81-20-01 of repetitively 
inspecting (using dye penetrant methods) the NLG actuator support 
structure and the front pressure bulkhead for cracks on JAL HP137 Mk1 
and Jetstream series 200 airplanes that do not have the front

[[Page 54583]]

pressure bulkhead strengthened in the area of the NLG jack attachment 
fitting (Modification No. 5127), and replacing or repairing any cracked 
NLG actuator support structure or cracked front pressure bulkhead. 
Accomplishment of the proposed inspections as specified in the notice 
of proposed rulemaking (NPRM) would be in accordance with Jetstream 
Service Bulletin (SB) No. 6/5, dated September 4, 1978.
--Require repetitively inspecting the NLG retraction jack upper 
mounting fitting and attachment hardware for security bolt failure and 
bolts with improper torque levels on the HP137 Mk1, Jetstream series 
200, and Jetstream Model 3101 airplanes, and replacing any failed 
security bolts and adjusting any bolt with an improper torque level. 
Accomplishment of the proposed inspections as specified in the NPRM 
would be in accordance with Jetstream SB 53-A-JA870510, which consists 
of the following pages and revision levels:

------------------------------------------------------------------------
              Pages                 Revision level           Date       
------------------------------------------------------------------------
3, 5, 6, 8, 9, and 10...........  Original Issue....  May 26, 1987.     
1, 2, 4, and 7..................  Revision 1........  Nov. 10, 1987.    
------------------------------------------------------------------------

--Require modifying the NLG retraction jack on the HP137 Mk1, Jetstream 
series 200, and Jetstream Models 3101 and 3201 airplanes as terminating 
action for all the repetitive inspections, including the inspections 
referenced in the Model 3201 maintenance manual. Accomplishment of the 
proposed modification as specified in the NPRM would be in accordance 
with Jetstream SB 53-JM 5285, which consists of the following pages and 
revision levels:

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

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. One comment was received regarding the 
proposed rule. An analysis of the comment follows:
    The commenter provides information on the company's fleet size and 
the estimated projection on when the proposed replacement would be 
mandatory on the affected airplanes in the company's fleet, as well as 
the number of repetitive inspections that would be required during that 
time. The commenter states that it is more economical for the company 
to incorporate the modification on its entire fleet immediately rather 
than continuing to repetitively inspect. The commenter also mentions 
that parts to modify the NLG retraction jack cost $1,800 instead of 
$1,600. The economic portion of this supplemental NPRM has been 
modified to reflect this change.

The FAA's Aging Commuter Aircraft Policy

    The actions specified in the NPRM are part of the FAA's aging 
commuter aircraft policy, which briefly states that, when a 
modification exists that could eliminate or reduce the number of 
required critical inspections, the modification should be incorporated. 
This policy is based on the FAA's determination that reliance on 
critical repetitive inspections on airplanes utilized in commuter 
service carries an unnecessary safety risk when a design change exists 
that could eliminate or, in certain instances, reduce the number of 
those critical inspections. In determining what inspections are 
critical, the FAA considers (1) the safety consequences of the airplane 
if the known problem is not detected by the inspection; (2) the 
reliability of the inspection such as the probability of not detecting 
the known problem; (3) whether the inspection area is difficult to 
access; and (4) the possibility of damage to an adjacent structure as a 
result of the problem.

Events Leading to the Issuance of This Supplemental NPRM

    As currently written, the existing NPRM would allow continued 
flight if cracks are found in the front pressure bulkhead membrane or 
actuator support structure when the cracks do not exceed certain 
limits. Since issuing the NPRM, the FAA has established a policy to 
disallow airplane operation when known cracks exist in primary 
structure (the front pressure bulkhead and actuator support structure 
are considered primary structure). For this reason, the FAA has 
determined that the crack limits contained in the NPRM should be 
eliminated and that AD action should be taken to require immediate 
replacement of any cracked front pressure bulkhead membrane or actuator 
support structure.

Explanation of the Provisions of the Proposed AD

    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, the 
proposed AD would:

--Retain the requirement contained in AD 81-20-01 of repetitively 
inspecting (using dye penetrant methods) the NLG actuator support 
structure and the front pressure bulkhead for cracks on JAL HP137 Mk1 
and Jetstream series 200 airplanes that do not have the front pressure 
bulkhead strengthened in the area of the NLG jack attachment fitting 
(Modification No. 5127), and replacing or repairing any cracked NLG 
actuator support structure or cracked front pressure bulkhead prior to 
further flight. Accomplishment of these proposed inspections would be 
in accordance with Jetstream Service Bulletin (SB) No. 6/5, dated 
September 4, 1978;
--Require repetitively inspecting the NLG retraction jack upper 
mounting fitting and attachment hardware for security bolt failure and 
bolts with improper torque levels on the HP137 Mk1, Jetstream series 
200, and Jetstream Model 3101 airplanes, and replacing any failed 
security bolts and adjusting any bolt with an improper torque level. 
Accomplishment of these proposed inspections would be in accordance 
with Jetstream SB 53-A-JA870510; and
--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.

Cost Impact

    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 per airplane to accomplish the proposed modification, and 
that the average labor rate is approximately $60 an hour. Parts cost 
approximately $1,800 per airplane. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$724,200 or $4,260 per airplane. This figure only takes into account 
the cost of the proposed inspection-terminating modification and does 
not take into account the cost of the repetitive inspections. The FAA 
has no way of determining the number of proposed repetitive inspections 
each HP137 Mk1, Jetstream series 200, and Jetstream

[[Page 54584]]

Model 3101 airplane owner/operator would incur over the life of the 
airplane.
    This figure is also based on the assumption that no affected 
airplane owner/operator has accomplished the proposed modification. The 
proposed action would eliminate the need for 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 to equip approximately 39 of the 
affected airplanes. Assuming that each set of parts has been installed 
on an affected airplane, the cost impact of the proposed modification 
upon the public would be reduced $166,140 from $724,200 to $558,060.
    The intent of the FAA's aging commuter airplane program is to 
ensure safe operation of airplanes that are in commercial service 
without adversely impacting private operators. Of the approximately 170 
airplanes in the U.S. registry that will be affected by this AD, the 
FAA has determined that approximately 95 percent are operated in 
scheduled passenger service by 10 different operators.

Regulatory Impact

    The regulations 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), 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 an improved design attachment bracket for 
the NLG retraction jack (Modification JM 5285) installed in 
accordance with the Accomplishment Instructions section of Jetstream 
SB 53-JM 5285:

--HP137 Mk1 airplanes, all serial numbers;
--Jetstream Series 200 airplanes, all serial numbers;
--Jetstream Model 3101 airplanes, all serial numbers; and
--Jetstream Model 3201 airplanes, serial numbers 601 through 840.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (e) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated in the body of this AD, unless 
already accomplished.
    To prevent failure of the nose landing gear (NLG) caused by a 
cracked NLG actuator support structure or cracked front pressure 
bulkhead, which could lead to nose gear collapse and damage to the 
airplane, accomplish the following:

    Note 2: The paragraph structure of this AD is as follows: Level 
1: (a), (b), (c), etc.; Level 2: (1), (2), (3), etc.; Level 3: (i), 
(ii), (iii), etc.; Level 2 and Level 3 structures are designations 
of the Level 1 paragraph they immediately follow.

    (a) For HP137 Mk1 and Jetstream series 200 airplanes that do not 
have the front pressure bulkhead strengthened in the area of the NLG 
jack attachment fitting (Modification 5127), upon accumulating 1,600 
landings or within the next 200 landings after the effective date of 
this AD, whichever occurs later, and thereafter at intervals not to 
exceed 200 landings until the modification required by paragraph (c) 
of this AD is incorporated, inspect (using dye penetrant methods) 
the nose landing gear actuator support structure, part number (P/N) 
137139C-13 and P/N 137139C-25, 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. This replacement does not 
eliminate the repetitive inspection requirement of this AD.
    (2) Prior to further flight after any of the inspections 
required by paragraph (a) of this AD, repair any cracked P/N 
137139C-25 NLG actuator support structure in accordance with the 
applicable maintenance manual. This repair does not eliminate the 
repetitive inspection requirement of this AD.
    (3) Prior to further flight after any of the inspections 
required by paragraph (a) of this AD, repair any cracked front 
pressure bulkhead membrane in accordance with the applicable 
maintenance manual. This repair does not eliminate the repetitive 
inspection requirement of this AD.
    (b) For all HP137 Mk1, Jetstream series 200, and Jetstream Model 
3101 airplanes, upon accumulating 3,500 landings or within the next 
200 landings after the effective date of this AD, whichever occurs 
later, accomplish the following:
    (1) Inspect the NLG retraction jack upper mounting fitting and 
attaching hardware for correct installation, security bolt failure, 
and bolts with improper torque levels in accordance with Part A and 
B of the ACCOMPLISHMENT INSTRUCTIONS section of Jetstream SB 53-A-
JA870510, which incorporates the following pages and revision 
levels:

------------------------------------------------------------------------
              Pages                 Revision level           Date       
------------------------------------------------------------------------
3, 5, 6, 8, 9, and 10...........  Original Issue....  May 26, 1987.     
1, 2, 4, and 7..................  Revision 1........  Nov. 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

[[Page 54585]]

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........  Nov. 12, 1992.    
2, 3, and 5 through 26..........  Revision 1........  May 18, 1992.     
------------------------------------------------------------------------

    (1) Incorporating Modification JM 5285 on Jetstream HP137 Mk1, 
Jetstream series 200, and Jetstream Model 3101 airplanes terminates 
the repetitive inspection requirement of this AD.
    (2) Incorporating Modification JM 5285 on Jetstream Model 3201 
airplanes eliminates the need for the repetitive inspections 
specified in the applicable maintenance manual.
    (3) Modification JM 5285 may be accomplished at any time prior 
to accumulating 25,000 landings or within the next 2,000 landings 
after the effective date of this AD, whichever occurs later, at 
which time it must be incorporated.
    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (e) An alternative method of compliance or adjustment of the 
initial or repetitive compliance times that provides an equivalent 
level of safety may be approved by the Manager, Brussels Aircraft 
Certification Division, Europe, Africa, Middle East office, FAA, c/o 
American Embassy, 1000 Brussels, Belgium. The request should be 
forwarded through an appropriate FAA Maintenance Inspector, who may 
add comments and then send it to the Manager, Brussels Aircraft 
Certification Division. Alternative methods of compliance approved 
in accordance with AD 81-20-01 (superseded by this action) are not 
considered approved as alternative methods of compliance with this 
AD.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Brussels Aircraft Certification Division.

    (f) 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 October 11, 1996.
Bobby W. Sexton,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-26861 Filed 10-18-96; 8:45 am]
BILLING CODE 4910-13-U