[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
