DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0511; Product Identifier 2017-NM-145-AD; Amendment
39-19425; AD 2018-19-24]
RIN 2120-AA64

Airworthiness Directives; BAE Systems (Operations) Limited Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all BAE
Systems (Operations) Limited Model 4101 airplanes. This AD was prompted
by a determination that inspection requirements for a number of
maintenance tasks are incorrect. This AD requires a one-time detailed
inspection of a certain fuselage frame and repair, if necessary, and a
revision of the maintenance or inspection program, as applicable, to
incorporate new or revised maintenance instructions and airworthiness
limitations. We are issuing this AD to address the unsafe condition on
these products.

DATES: This AD is effective November 7, 2018.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of November 7,
2018.

ADDRESSES: For service information identified in this final rule,
contact BAE Systems (Operations) Limited, Customer Information
Department, Prestwick International Airport, Ayrshire, KA9 2RW,
Scotland, United Kingdom; telephone +44 1292 675207; fax +44 1292
675704; email RApublications@baesystems.com; internet http://www.baesystems.com/Businesses/RegionalAircraft/index.htm. You may
view this service information at the FAA, Transport Standards Branch, 2200
South 216th St., Des Moines, WA. For information on the availability of
this material at the FAA, call 206-231-3195. It is also available on
the internet at http://www.regulations.gov by searching for and
locating Docket No. FAA-2018-0511.

Examining the AD Docket

You may examine the AD docket on the internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2018-
0511; or in person at Docket Operations between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays. The AD docket contains
this final rule, the regulatory evaluation, any comments received, and
other information. The address for Docket Operations (phone: 800-647-
5527) is U.S. Department of Transportation, Docket Operations, M-30,
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE,
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Todd Thompson, Aerospace Engineer,
International Section, Transport Standards Branch, FAA, 2200 South
216th St., Des Moines, WA 98198; telephone and fax 206-231-3228.

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 by adding an AD that would apply to all BAE Systems
(Operations) Limited Model 4101 airplanes. The NPRM published in the
Federal Register on June 14, 2018 (83 FR 27721). The NPRM was prompted
by a determination that inspection requirements for a number of maintenance
tasks are incorrect.
The NPRM proposed to require a one-time detailed inspection of a certain
fuselage frame and repair, if necessary, and a revision of the
maintenance or inspection program, as applicable, to incorporate new or
revised maintenance instructions and airworthiness limitations.
We are issuing this AD to address cracking in fuselage frame 90,
which could cause it to fail and thereby compromise the structural
integrity of the aircraft pressure hull. We are also issuing this AD to
address fatigue damage of various airplane structures, which could
result in reduced structural integrity of the airplane.
The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Union, has issued EASA AD
2017-0187, dated September 22, 2017 (referred to after this as the
Mandatory Continuing Airworthiness Information, or ``the MCAI''), to
correct an unsafe condition for all BAE Systems (Operations) Limited
Model 4101 airplanes. The MCAI states:

Maintenance instructions for BAE Jetstream 4100 aeroplanes,
which are approved by EASA, are defined in BAE Systems (Operations)
Ltd Jetstream 4100 Service Bulletin (SB) J41-51-001, which
references certain Aircraft Maintenance Manual (AMM) tasks. These
instructions have been identified as mandatory for continued
airworthiness.
Failure to accomplish these instructions could result in an
unsafe condition.
CAA UK [Civil Aviation Authority United Kingdom] issued AD 005-
02-2002 [which corresponds to FAA AD 2005-15-11, Amendment 39-14200
(70 FR 43025, July 26, 2005) (``AD 2005-15-11'')] to require
operators to comply with the inspection instructions as referenced
in SB J41-51-001 at original issue.
Since that [CAA UK ] AD was issued, BAE Systems (Operations) Ltd
have determined that the inspection requirements for a number of
maintenance tasks are incorrect. Consequently, existing inspection
items 52-20-013, 53-10-006, 53-10-025, 53-10-029 and 53-10-079 will
be amended in Chapter 05 of the AMM. Compliance periods for these
changes are given in BAE Systems (Operations) Ltd SB J41-51-001 (now
at Revision 4) and BAE Systems (Operations) Ltd Alert SB J41-A53-
058. Those fatigue inspections detailed in SB J41-51-001, at
Revision 3 or earlier, have now been incorporated into Chapter 05 of
the AMM. To avoid duplication these tasks are deleted from SB J41-
51-001 at Revision 4.
For the reason described above, this [EASA] AD retains the
requirements of CAA UK AD 005-02-2002, which is superseded, and
requires accomplishment of the actions specified in BAE Systems
(Operations) Ltd Jetstream 4100 SB J41-51-001 Revision 4 and Alert
SB J41-A53-058 (hereafter collectively referred to as `the SB' in
this [EASA] AD).

The actions include a one-time detailed inspection of fuselage
frame 90 for cracking or fatigue damage and repair if necessary, and
revision of the maintenance or inspection program, as applicable, to
incorporate new or revised maintenance instructions and airworthiness
limitations. This AD was prompted by a determination that it is
possible for cracks in fuselage frame 90 to exceed the critical length
for failure in less time than the current inspection interval, and by a
determination that inspection requirements for a number of maintenance
tasks involving certain airworthiness limitations are incorrect. The
unsafe condition is cracking in fuselage frame 90, which could cause it
to fail and thereby compromise the structural integrity of the aircraft
pressure hull; and fatigue damage of various airplane structures, which
could result in reduced structural integrity of the airplane.
You may examine the MCAI in the AD docket on the internet at http://
www.regulations.gov by searching for and locating Docket No. FAA-2018-
0511.

Comments

We gave the public the opportunity to participate in developing
this final rule. We received no comments on the NPRM or on the
determination of the cost to the public.

Conclusion

We reviewed the relevant data and determined that air safety and
the public interest require adopting this final rule as proposed,
except for minor editorial changes. We have determined that these minor
changes:
Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

BAE Systems (Operations) Limited has issued the following service
information.
Service Bulletin J41-51-001, Revision 4, dated July 11,
2017. This service information describes new inspections and revisions
to existing inspection requirements and thresholds.
Alert Service Bulletin J41-A53-058, dated December 6,
2016. This service information describes procedures for a detailed
inspection for cracking or fatigue damage of fuselage frame 90.
This service information is reasonably available because the
interested parties have access to it through their normal course of
business or by the means identified in the ADDRESSES section.

Costs of Compliance

We estimate that this AD affects 4 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs

We have determined that revising the maintenance or inspection
program takes an average of 90 work-hours per operator, although we
recognize that this number may vary from operator to operator. In the
past, we have estimated that this action takes 1 work-hour per
airplane. Since operators incorporate maintenance or inspection program
changes for their affected fleet(s), we have determined that a per-
operator estimate is more accurate than a per-airplane estimate.
Therefore, we estimate the total cost per operator to be $7,650 (90
work-hours x $85 per work-hour).
We have received no definitive data that would enable us to provide
cost estimates for the on-condition actions specified in this AD.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
This AD is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to transport category airplanes and
associated appliances to the Director of the System Oversight Division.

Regulatory Findings

This AD will not have federalism implications under Executive Order
13132. This AD will not have a substantial direct effect 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.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) 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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):