[Federal Register Volume 62, Number 100 (Friday, May 23, 1997)]
[Rules and Regulations]
[Pages 28318-28321]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-12023]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-CE-44-AD; Amendment 39-10017; AD 97-10-05]


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to certain Jetstream Aircraft Limited (JAL) HP137 Mk1, 
Jetstream series 200, and Jetstream Models 3101 and 3201 airplanes. 
This AD requires repetitively inspecting the main landing gear (MLG) 
pintle to cylinder interface area for cracks, and replacing any MLG 
cylinder where a crack of any length is found in the MLG pintle to 
cylinder interface area. This AD results from reports of MLG cracks in 
the area of the pintle to cylinder interface on three of the affected 
airplanes. The actions specified by this AD are intended to prevent 
failure of the MLG caused by cracks in the pintle to cylinder interface 
area, which could result in loss of control of the airplane during 
landing operations.

DATES: Effective July 11, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 11, 1997.

ADDRESSES: Service information that applies to this 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 may also be 
examined at the Federal Aviation Administration (FAA), Central Region, 
Office of the Assistant Chief Counsel, Attention: Rules Docket 95-

[[Page 28319]]

 CE-44-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106; 
or at the Office of the Federal Register, 800 North Capitol Street, 
NW., suite 700, Washington, DC.

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) 508.2715; facsimile (32 2) 230.6899; or Mr. S.M. 
Nagarajan, 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:

Events Leading to the Issuance of This AD

    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 
was published in the Federal Register as a notice of proposed 
rulemaking (NPRM) on September 19, 1995 (60 FR 48429). The NPRM 
proposed to require repetitively inspecting the MLG pintle to cylinder 
interface area for cracks, and replacing any MLG cylinder where a crack 
is found in the MLG pintle to cylinder interface area that exceeds 
certain limits.
    Interested persons were afforded an opportunity to participate in 
the making of this amendment. One comment was received in favor of the 
proposed rule and no comments were received regarding the FAA's 
determination of the cost to the public.
    As written, the original NPRM would have allowed continued flight 
if cracks are found in the MLG pintle to cylinder interface area when 
the cracks do not exceed certain limits. Since issuing that NPRM, the 
FAA established a policy to disallow airplane operation when known 
cracks exist in primary structure, unless the ability to sustain 
ultimate load with these cracks is proven. This policy was established 
based on the FAA's extensive analysis of the consequences of flying 
with cracks in primary structure. The MLG pintle to cylinder interface 
area is considered primary structure, and the FAA has not received any 
analysis to prove that ultimate load can be sustained with cracks in 
this area.
    For this reason, the FAA determined that the crack limits specified 
in the NPRM should be eliminated and that the NPRM should be revised to 
propose immediate replacement of the MLG cylinder if any cracks are 
found in the MLG pintle to cylinder interface area. Since revising the 
proposed AD to require immediate replacement of the MLG cylinder when 
cracks are found in the MLG pintle to cylinder interface area went 
beyond the scope of what was presented in the original NPRM, the FAA 
published a supplemental NPRM in the Federal Register on March 19, 1996 
(61 FR 12051, March 25, 1996).
    After publication of this supplemental NPRM, the FAA re-examined 
all information related to this subject and determined that the actions 
proposed were still a valid safety issue, but that more stringent 
repetitive inspection intervals needed to be established. Specifically, 
the MLG pintle to cylinder interface area would need to be inspected 
initially ``upon accumulating 8,000 landings on an affected MLG.'' 
(instead of 8,500 landings), ``* * * and, thereafter at intervals not 
to exceed 1,200 landings * * *'' (instead of 4,000 landings). The more 
stringent inspection intervals were based on an analysis done by JAL 
and subsequently evaluated and approved by the FAA. The FAA issued 
another supplemental NPRM that was published in the Federal Register on 
December 17, 1996 (61 FR 66238) to incorporate the more stringent 
inspection intervals.
    Interested persons were again afforded an opportunity to 
participate in the making of this amendment. No comments were received 
regarding the substance of the second supplemental NPRM or the FAA's 
determination of the cost to the public.

The FAA's Determination

    After careful review of all available information related to the 
subject presented above, the FAA has determined that air safety and the 
public interest require the adoption of the AD as proposed in the 
second supplemental NPRM, except for minor editorial corrections. The 
FAA has determined that these minor corrections will not change the 
meaning of the AD and will not add any additional burden upon the 
public than was already proposed.

Relevant Service Information

    Accomplishment of the inspections required by this AD are required 
in accordance with Jetstream Alert Service Bulletin 32-JA 960142, dated 
March 15, 1996; AP Precision Hydraulics Ltd. Service Bulletin 32-56, 
Revision 3, dated February 1995; and Jetstream Alert Service Bulletin 
32-A-JA 941245, Revision 3, dated March 15, 1996, which incorporates 
the following pages:

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                  Pages                              Revision level                           Date              
----------------------------------------------------------------------------------------------------------------
 1 through 4.............................  Revision 3........................  March 15, 1996.                  
5 through 11.............................  Revision 2........................  March 28, 1995.                  
----------------------------------------------------------------------------------------------------------------

Cost Impact

    The FAA estimates that 250 airplanes in the U.S. registry will be 
affected by this AD, that it will take approximately 6 workhours per 
airplane to accomplish this AD, and that the average labor rate is 
approximately $60 an hour. Based on these figures, the total cost 
impact of the required inspection on U.S. operators is estimated to be 
$90,000. This figure does not take into account the cost of repetitive 
inspections or the cost of replacement MLG cylinders if any crack is 
found in the MLG pintle to cylinder interface area. The FAA has no way 
of determining the number of repetitive inspections each owner/operator 
would incur over the life of the airplane or the number of MLG 
cylinders that may be found cracked during the inspections required by 
this AD.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does 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) will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities

[[Page 28320]]

under the criteria of the Regulatory Flexibility Act. A copy of the 
final evaluation prepared for this action is contained 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 adding a new airworthiness directive 
(AD) to read as follows:

97-10-05  Jetstream Aircraft Limited: Amendment 39-10017; Docket No. 
95-CE-44-AD.

    Applicability: HP 137 Mk1, Jetstream series 200, and Jetstream 
Models 3101 and 3201 airplanes (all serial numbers), certificated in 
any category, that are equipped with a main landing gear (MLG) 
incorporating one of the following part numbers (or FAA-approved 
equivalent):


1863                    1863/4A                1863/4B                  
1863/4C                 1864                   1864/4A                  
1864/4B                 1864/4C                BOOA702850A              
BOOA702851A             BOOA702925A            BO1A702925A              
BOOA703065A             BO1A703065A            BOOA703030A              
BOOA702926A             BO1A702926A            BOOA703066A              
BO1A703066A             BOOA703031A                                     
                                                                        

    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 (d) 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 initially upon accumulating 8,000 landings 
on an affected MLG or within the next 100 landings after the 
effective date of this AD, whichever occurs later, unless already 
accomplished, and thereafter at intervals not to exceed 1,200 
landings accumulated on an affected MLG.

    Note 2: If the number of landings is unknown, hours time-in-
service (TIS) may be used by multiplying the number of hours TIS by 
0.75. If hours TIS are utilized to calculate the number of landings, 
this would make the AD effective ``initially upon accumulating 
10,667 hours TIS on an affected MLG or within the next 133 hours TIS 
after the effective date of this AD, whichever occurs later, and 
thereafter at intervals not to exceed to 1,600 hours TIS accumulated 
on an affected MLG.''

    To prevent failure of the MLG caused by cracks in the pintle to 
cylinder interface area, which could result in loss of control of 
the airplane during landing operations, accomplish the following:
    (a) Inspect the MLG pintle to cylinder interface area for cracks 
in accordance with one of the following:
    (1) Using non-destructive testing (NDT) eddy current methods, in 
accordance with AP Precision Hydraulics Ltd. Service Bulletin 32-56, 
Revision 3, dated February 1995; or
    (2) Using fluorescent penetrant methods, in accordance with 
Appendix 1 in Jetstream Service Bulletin 32-JA 960142, dated March 
15, 1996; or Appendix 2 in Jetstream Alert Service Bulletin 32-A-JA 
941245, Revision 3, dated March 15, 1996, which incorporates the 
following pages:

----------------------------------------------------------------------------------------------------------------
                  Pages                              Revision level                           Date              
----------------------------------------------------------------------------------------------------------------
1 through 4..............................  Revision 3........................  March 15, 1996.                  
5 through 11.............................  Revision 2........................  March 28, 1995.                  
----------------------------------------------------------------------------------------------------------------

    (b) If any crack is found during any inspection required by this 
AD, prior to further flight, replace the MLG cylinder with a 
serviceable part in accordance with the applicable maintenance 
manual. Replacing the MLG cylinder does not eliminate the repetitive 
inspection requirement of this AD.

    Note 3: The ``prior to further flight'' replacement compliance 
time required by this AD if a MLG cylinder is cracked is different 
from the compliance times referenced in Jetstream Service Bulletin 
32-JA 960142, dated March 15, 1996; Precision Hydraulics Ltd. 
Service Bulletin 32-56, Revision 3, dated February 1995, or 
Jetstream Alert Service Bulletin 32-A-JA 941245, Revision 3, dated 
March 15, 1996. This AD takes precedence over any service 
information.

    (c) 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.
    (d) An alternative method of compliance or adjustment of the 
initial and 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, B-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.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Brussels Aircraft Certification Division.

    (e) The inspections required by this AD shall be done in 
accordance with either Jetstream Service Bulletin 32-JA 960142, 
dated March 15, 1996; Precision Hydraulics Ltd. Service Bulletin 32-
56, Revision 3, dated February 1995; or Jetstream Alert Service 
Bulletin 32-A-JA 941245, Revision 3, dated March 15, 1996, which 
incorporates the following pages:

----------------------------------------------------------------------------------------------------------------
                  Pages                              Revision level                           Date              
----------------------------------------------------------------------------------------------------------------
1 through 4..............................  Revision 3........................  March 15, 1996.                  
5 through 11.............................  Revision 2........................  March 28, 1995.                  
----------------------------------------------------------------------------------------------------------------


[[Page 28321]]

    This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from 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, 20041-6029. Copies may 
be inspected at the FAA, Central Region, Office of the Assistant 
Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, 
or at the Office of the Federal Register, 800 North Capitol Street, 
NW., suite 700, Washington, DC.
    (f) This amendment (39-10017) becomes effective on July 11, 
1997.

    Issued in Kansas City, Missouri, on May 2, 1997.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 97-12023 Filed 5-22-97; 8:45 am]
BILLING CODE 4910-13-U