[Federal Register Volume 61, Number 97 (Friday, May 17, 1996)]
[Rules and Regulations]
[Pages 24884-24887]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-12497]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-CE-79-AD; Amendment 39-9627; AD 96-11-02]
RIN 2120-AA64


Airworthiness Directives; Jetstream Aircraft Limited (Formerly 
British Aerospace, Regional Airlines Limited) HP137 Mk1, Jetstream 
Series 200, and Jetstream Model 3101 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 Jetstream Aircraft Limited (JAL) HP137 Mk1, Jetstream series 
200, and Jetstream Model 3101 airplanes. This action requires 
repetitively inspecting the spigot housing plate for cracks at the 
wing/fuselage forward attachment sliding joint, replacing any cracked 
housing plate, repetitively inspecting the spigots and spigot posts for 
corrosion and installing improved spigots if corrosion is found that 
exceeds certain limits, and eventually installing improved spigots if 
corrosion that does not exceed certain limits is found. For certain 
affected airplanes, this action requires repetitively inspecting the 
spigot bushes for migration gaps, replacing the bushes with modified 
bushes if gaps are found that exceed 0.5 inch, and eventually replacing 
the bushes with modified bushes if migration gaps are not found. 
Reports of bush migration gaps found on three of the affected airplanes 
and another report of corrosion and several cracks found on the spigot 
housing plate on a Jetstream Model 3101 airplane prompted this action. 
The actions specified by this AD are intended to prevent structural 
failure of the wing/fuselage area caused by a cracked or corroded 
spigot housing assembly.

DATES: Effective July 2, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 2, 1996.

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-CE-
79-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: Ms. Dorenda Baker, Program Manager, 
Brussels Aircraft Certification Office, 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. Jeffrey Morfitt, 
Project Officer, Small Airplane Directorate, Aircraft Certification 
Service, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64105; 
telephone (816) 426-6932; facsimile (816) 426-2169.

SUPPLEMENTARY INFORMATION:

Events Leading to the AD

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to include an AD that would apply to JAL HP137 Mk1, 
Jetstream series 200, and Jetstream Model 3101 airplanes was published 
in the Federal Register on January 19, 1996 (61 FR

[[Page 24885]]

1295). The action proposed to require repetitively inspecting the 
spigot housing plate for cracks at the wing/fuselage forward attachment 
sliding joint, replacing any cracked housing plate, repetitively 
inspecting the spigots and spigot posts for corrosion and installing 
improved spigots if corrosion is found, and eventually installing 
improved spigots if corrosion is not found. For certain affected 
airplanes, the proposed action would require repetitively inspecting 
the spigot bushes for migration gaps, replacing the bushes with 
modified bushes if gaps are found that exceed 0.5 inch, and eventually 
replacing the bushes with modified bushes if migration gaps are not 
found. Accomplishment of the proposed inspections would be in 
accordance with BAe Jetstream Alert Service Bulletin (ASB) 57-A-JA 
920640, dated February 19, 1993; and Jetstream Service Bulletin (SB) 
57-JA 930941, Revision 2, dated November 11, 1994. Accomplishment of 
the proposed modifications would be in accordance with BAe Jetstream SB 
57-JM 5259, dated February 5, 1993, and Erratum No. 1 to SB 57-JM 5259, 
dated February 8, 1993; and Jetstream SB 57-JM 5326, dated September 3, 
1993.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received from two different commenters. One of these 
commenters supports the proposal as written.

Comment Resolution

    JAL states that the corrosion limits specified in paragraphs (b)(1) 
and (b)(2) of the AD only specify the spigot posts. JAL further states 
that Jetstream SB 57-JA 930941, Revision No. 2, dated November 11, 
1994, also specifies corrosion limits for the spigots. JAL requests 
that these corrosion limits and applicable service bulletin 
instructions be added to the final rule. The FAA concurs and has 
revised the AD accordingly.
    JAL also recommends that the repetitive inspection interval be 
changed to 48 calendar months instead of 12 calendar months to coincide 
with Jetstream SB 57-JA 93041. The FAA established the initial 
inspection in the proposal at 12 calendar months and meant to establish 
the repetitive inspection interval at 48 calendar months, but 
inadvertently established the repetitive inspection interval at 12 
calendar months. The FAA's analysis of data initially submitted by JAL 
indicates that repetitively inspecting the spigot housing area for 
cracks and corrosion at 48 calendar month intervals provides the level 
of safety necessary to correct the unsafe condition. The final rule AD 
has been revised to reflect this change.
    JAL asks whether an owner/operator who found a cracked spigot 
housing plate could apply for an alternative method of compliance to 
allow 150 flight hours before installation rather than prior to further 
flight when a crack is found that is shorter than 0.2 inch. JAL states 
that this would allow the owner/operator of the affected airplane time 
to obtain the necessary parts, and also states that fatigue tests have 
demonstrated slow crack growth. The FAA allows any owner/operator to 
submit a request for an alternative method of compliance, including an 
extension of the compliance time. The owner/operator should submit the 
request with all substantiating data in accordance with the provisions 
in the AD. The FAA will evaluate each request to determine whether the 
alternative method of compliance establishes an equivalent level of 
safety to the actions of the AD, and then will either approve or reject 
the request accordingly.
    No comments were received regarding the FAA's estimate of the cost 
impact on the public.
    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 rule as proposed except for 
the changes previously discussed and minor editorial corrections. The 
FAA has determined that these changes and minor corrections will not 
change the meaning of the AD and will not add any additional burden 
upon the public than was already proposed.

Aspects of the Action

    The alternative to incorporating new modified spigots and bushes 
would be to require repetitive inspections. FAA aging commuter-class 
aircraft policy states that reliance on critical repetitive inspections 
carries an unnecessary safety risk when a design change exists that 
could eliminate or, in certain instances, reduce the number of those 
critical inspections. Therefore, the required spigot and bush 
replacements is consistent with the FAA's commuter-class aircraft 
policy.
    The compliance times of the repetitive inspections of the spigots 
and spigot posts for corrosion and subsequent replacement, if 
necessary, are presented in calendar time instead of hours time-in-
service (TIS). Corrosion can occur on airplanes regardless of whether 
the airplane is in service or in storage. Therefore, to ensure that 
corrosion is detected and corrected on all airplanes within a 
reasonable period of time without inadvertently grounding any 
airplanes, a compliance schedule based upon calendar time instead of 
hours TIS is utilized.

Cost Impact

    The FAA estimates that 143 airplanes in the U.S. registry will be 
affected by this AD, that it will take approximately 61 workhours per 
airplane to accomplish the inspections and modifications, and that the 
average labor rate is approximately $60 an hour. Parts cost 
approximately $320 per airplane. Based on these figures, the total cost 
impact of this AD on U.S. operators is estimated to be $569,140 or 
$3,980 per airplane. This figure only takes into account the cost of 
initial inspections and does not take into account repetitive 
inspection costs. The FAA has no way of determining the number of 
repetitive inspections each affected airplane owner/operator will incur 
over the life of the airplane.
    The approximately 61 workhours it will take to accomplish the 
required actions is based on each inspection and modification being 
accomplished separately. The FAA anticipates that many owners/operators 
of the affected airplanes will schedule all of the required actions to 
be accomplished at the same time, thereby reducing the labor costs 
associated with accomplishing these actions.
    In addition, Jetstream Aircraft Limited has informed the FAA that 
parts have been distributed to equip approximately 40 airplanes. 
Assuming that each set of parts is installed on an affected HP137 Mk1, 
Jetstream series 200, or Jetstream Model 3101 airplane, the cost impact 
of this AD upon U.S. operators is reduced $159,200 from $569,140 to 
$409,940.

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

[[Page 24886]]

substantial number of small entities 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:

96-11-02   Jetstream Aircraft Limited: Amendment 39-9627; Docket No. 
95-CE-79-AD.

    Applicability: HP137 Mk1, Jetstream series 200, and Jetstream 
Model 3101 airplanes (all serial numbers), certificated in any 
category.
    Compliance: Required as indicated in the body of this AD, unless 
already accomplished.

    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 (g) 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.

    To prevent structural failure of the wing/fuselage area caused 
by a cracked spigot housing assembly, accomplish the following:
    (a) For all affected airplanes, upon the accumulation of 7,200 
hours time-in-service (TIS) or within the next 1,200 hours TIS after 
the effective date of this AD, whichever occurs later, and 
thereafter at intervals not to exceed 7,200 hours TIS, accomplish 
the following:
    (1) Inspect the spigot housing plate at the wing/fuselage 
forward attachment sliding joint for cracks in accordance with Part 
1 of the ACCOMPLISHMENT INSTRUCTIONS section of Jetstream Service 
Bulletin (SB) 57-JA 930941, Revision No. 2, dated November 11, 1994.
    (2) If a cracked spigot housing plate is found, prior to further 
flight, replace the cracked spigot housing plate in accordance with 
Part 3 of the ACCOMPLISHMENT INSTRUCTIONS section of Jetstream SB 
57-JA 930941, Revision No. 2, dated November 11, 1994.
    (3) Replacing the spigot housing plate does not eliminate the 
7,200-hour TIS interval repetitive inspection requirement.
    (b) For all affected airplanes, within the next 12 calendar 
months after the effective date of this AD, and thereafter at 
intervals not to exceed 48 calendar months until Modification No. JM 
5326 and Modification No. JM 5259 (as applicable) are incorporated 
as required by paragraphs (d)(1) and (d)(2) of this AD, inspect the 
spigots and spigot posts for corrosion in accordance with Part 2 of 
the ACCOMPLISHMENT INSTRUCTIONS section of Jetstream SB 57-JA 
930941, Revision No. 2, dated November 11, 1994.
    (1) If corrosion damage is found in the spigot post that is 0.06 
inch (1.52 mm) or less deep and does not extend to within 0.9 inch 
(22.9 mm) from either end of the bore, prior to further flight, 
treat the corrosion in accordance with paragraph (8)(d) of the 
ACCOMPLISHMENT INSTRUCTIONS section of Jetstream SB 57-JA 930941, 
Revision No. 2, dated November 11, 1994.
    (2) If corrosion damage in the spigot post is found that is more 
than 0.06 inch (1.52 mm) or extends to within 0.9 inch (22.9 mm) 
from either end of the bore, prior to further flight, obtain a 
repair scheme from the manufacturer through the Brussels Aircraft 
Certification Office (ACO) at the address specified in paragraph (g) 
of this AD, and incorporate this repair scheme.
    (3) If corrosion damage in the spigot is found that penetrates 
the protective surface of the spigot, within four calendar months 
after finding the corrosion damage, replace both wing/fuselage 
spigots with new modified spigots (Modification No. JM 5326) in 
accordance with Jetstream SB 57-JM 5326, dated September 3, 1993. 
Modification No. JM 5326 incorporates a new P/N 13781B401 spigot 
assembly.
    (c) For all affected HP137 Mk1 airplanes and all affected 
Jetstream series 200 airplanes, and Jetstream Model 3101 airplanes 
with a serial number in the range of 601 through 702 (inclusive), 
within the next 1,200 hours TIS after the effective date of this AD, 
inspect the wing/fuselage forward attachment spigot bushes for 
migration gaps in accordance with the ACCOMPLISHMENT INSTRUCTIONS 
section of BAe Jetstream Alert SB 57-A-JA 920640, dated February 19, 
1993.
    (1) If no migration gaps are found, reinspect at intervals not 
to exceed 4,500 hours TIS until Modification No. JM 5259 is 
incorporated. If migration gaps are found upon reinspection, install 
modified bushes as specified in paragraph (c)(2) or (c)(3) of this 
AD.
    (2) If migration gaps are found that are 0.5 inch or less, 
reinspect at intervals not to exceed 900 hours TIS until 
Modification No. JM 5259 is incorporated. If migration gaps are 
found upon reinspection that are larger than .5 inch, accomplish 
paragraph (c)(3) of this AD, as applicable.
    (3) If migration gaps are found that are larger than 0.5 inch, 
within 150 hours TIS after the last inspection required by paragraph 
(c)(1) or (c)(2) of this AD, install modified bushes at the wing/
fuselage forward attachment spigots (Modification JM 5259) in 
accordance with the ACCOMPLISHMENT INSTRUCTIONS section of BAe 
Jetstream SB 57-JM 5259, dated February 5, 1993, and Erratum No. 1 
to SB 57-JM 5259, dated February 8, 1993.
    (d) Upon accumulating 25,000 hours TIS or within 1,000 hours TIS 
after the effective date of this AD, whichever occurs later, 
accomplish the following:
    (1) For all affected HP137 Mk1, Jetstream series 200, and 
Jetstream Model 3101 airplanes, replace both wing/fuselage spigots 
with new modified spigots (Modification No. JM 5326) in accordance 
with Jetstream SB 57-JM 5326, dated September 3, 1993; and
    (2) For all affected HP137 Mk1 airplanes and all affected 
Jetstream series 200 airplanes, and Jetstream Model 3101 airplanes 
with a serial number in the range of 601 through 702 (inclusive), 
install modified bushes at the wing/fuselage forward attachment 
spigots (Modification No. JM 5259) in accordance with the 
ACCOMPLISHMENT INSTRUCTIONS section of BAe Jetstream SB 57-JM 5259, 
dated February 5, 1993, and Erratum No. 1 to SB 57-JM 5259, dated 
February 8, 1993.
    (3) Incorporating Modification No. JM 5259 eliminates the 
requirement of repetitively inspecting the wing/fuselage forward 
attachment spigot bushes for migration gaps as required by all 
designations of paragraph (c) of this AD.
    (e) Incorporating both Modification No. JM 5326 and Modification 
No. JM 5259 eliminates the repetitive inspections required by all 
designations of paragraphs (b) and (c) of this AD. This does not 
eliminate the repetitive inspections of the spigot housing plate as 
required by paragraph (a) of this AD.
    (f) 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.
    (g) 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Brussels ACO.

    (h) The inspections required by this AD shall be done in 
accordance with BAe Jetstream Alert Service Bulletin 57-A-JA 920640, 
dated February 19, 1993; and

[[Page 24887]]

Jetstream Service Bulletin 57-JA 930941, Revision 2, dated November 
11, 1994. The modifications required by this AD shall be done in 
accordance with BAe Jetstream Service Bulletin 57-JM 5259, dated 
February 5, 1993, and Erratum No. 1 to Service Bulletin 57-JM 5259, 
dated February 8, 1993; and Jetstream Service Bulletin 57-JM 5326, 
dated September 3, 1993. 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.
    (i) This amendment (39-9627) becomes effective on July 2, 1996.

    Issued in Kansas City, Missouri, on May 10, 1996.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 96-12497 Filed 5-16-96; 8:45 am]
BILLING CODE 4910-13-U