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

ACTION: Final rule.

SUMMARY: We are adopting a new airworthiness directive (AD) for
Ballonbau Worner GmbH Models NL-280/STU, NL-380/STU, NL-510/STU,
NL-640/STU, NL-840/STU, and NL-1000/STU balloons. This AD results from
mandatory continuing airworthiness information (MCAI) issued by an
aviation authority of another country to identify and correct an unsafe
condition on an aviation product. The MCAI describes the unsafe
condition as current inspection intervals are no longer adequate to
ensure timely detection of deterioration or damage. We are issuing this
AD to require actions to address the unsafe condition on these
products.

DATES: This AD is effective May 27, 2014.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in the AD as of May 27, 2014.

ADDRESSES: You may examine the AD docket on the Internet at http://
www.regulations.gov by searching for and locating Docket No. FAA-2014-
0041; or in person at Document Management Facility, 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 service information identified in this AD, contact Ballonbau
Worner GmbH, Zirbelstrasse 57c, D-86154 Augsburg, Germany;
telephone: +49 821 4504060; fax: +49 821 419641; Internet:
www.ballonbau.de. You may view this referenced service information at
the FAA, Small Airplane Directorate, 901 Locust, Kansas City, Missouri
64106. For information on the availability of this material at the FAA,
call (816) 329-4148.

FOR FURTHER INFORMATION CONTACT: Karl Schletzbaum, Aerospace Engineer,
FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City,
Missouri 64106; telephone: (816) 329-4123; fax: (816) 329-4090; email:
karl.schletzbaum@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to adding an AD that would apply to Ballonbau Worner GmbH
Model NL-280/STU, NL-380/STU, NL-510/STU, NL-640/STU, NL-840/STU, and
NL-1000/STU airplane. The NPRM was published in the Federal Register on
January 31, 2014 (79 FR 5319). The NPRM proposed to correct an unsafe
condition for the specified products and was based on mandatory
continuing airworthiness information (MCAI) originated by an aviation
authority of another country. The MCAI states:

The results of an analysis of NL-STU maintenance data revealed
that the current inspection intervals are no longer adequate to
ensure timely detection of deterioration or damage, which could
affected the structural integrity of the balloon.
This condition, if not detected and corrected, could lead to
failure of balloon components or envelope, possibly resulting in
loss of the balloon.
To address this potential unsafe condition, Ballonbau
Worner developed new, more detailed and descriptive
Instructions for Continued Airworthiness (at the same time separated
from the Flight Manual) and issued Technische Mitteilung/Technical
Note EASA.BA.009-6 to inform all operators.
For the reasons described above, EASA issued AD 2013-0293 to
require compliance with the updated Instructions for Continued
Airworthiness. This AD is revised to extend the compliance time for
the initial porosity test, for balloons which have already exceeded
the relevant threshold.

The MCAI can be found in the AD docket on the Internet at: http://www.regulations.gov/#!documentDetail;D=FAA-2014-0041-0002.

Comments

We gave the public the opportunity to participate in developing
this AD. We received no comments on the NPRM (79 FR 5319, January 31,
2014) 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 the AD 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 (79 FR 5319, January 31, 2014) for correcting the unsafe
condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM (79 FR 5319, January 31, 2014).

Costs of Compliance

We estimate that this AD will affect 6 products of U.S. registry.
The scope of the inspections may vary depending on the condition of the
balloon. We have no way of knowing how extensive an inspection may be
necessary for each balloon. The scope of damage found in the
inspections could vary significantly from balloon to balloon. We have
no way of determining how much damage may be found on each balloon or
the cost to repair damaged parts on each balloon or the number of
balloons that may require repair.

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.

Regulatory Findings

We determined that 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 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.

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-2014-
0041; or in person at the Docket Management Facility between 9 a.m. and
5 p.m., Monday through Friday, except Federal holidays. The AD docket
contains the NPRM, the regulatory evaluation, any comments received,
and other information. The street address for the Docket Office
(telephone (800) 647-5527) is in the ADDRESSES section. Comments will
be available in the AD docket shortly after receipt.

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 AD: