DEPARTMENT OF TRANSPORTATION

FEDERAL AVIATION ADMINISTRATION

14 CFR Part 39

[Docket No. FAA-2010-0260; Directorate Identifier 2010-CE-015-AD]
RIN 2120-AA64

AIRWORTHINESS DIRECTIVES; GROB-WERKE (Type Certificate Previously
Held by BURKHART GROB Luft- und Raumfahrt) Models G115C, G115D and
G115D2 Airplanes

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

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of
the comment period.

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SUMMARY: We are  revising an earlier  NPRM for the  products listed above.
This  proposed   AD  results   from  mandatory   continuing  airworthiness
information (MCAI) originated 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:

The manufacturer has received a  report of a failed canopy  jettison test,
during  a regular  maintenance check.  The investigation  revealed that  a
cable shroud of the jettison system protruded the canopy structure,  which
probably  caused  the malfunction.  Inability  to jettison  the  canopy in
flight would prevent evacuation of the aeroplane in case of need.

The proposed  AD would  require actions  that are  intended to address the
unsafe condition described in the MCAI.

DATES: We must receive comments on this proposed AD by July 19, 2010.

ADDRESSES: You may send comments by any of the following methods:

Federal eRulemaking Portal: Go to http:// www.regulations.gov. Follow  the
instructions for submitting comments.

Fax: (202) 493-2251.

Mail: U.S.  Department of  Transportation, Docket  Operations, M-30,  West
Building  Ground  Floor,  Room  W12-140,  1200  New  Jersey  Avenue,  SE.,
Washington, DC 20590.

Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30,
West Building  Ground Floor,  Room W12-140,  1200 New  Jersey Avenue, SE.,
Washington, DC 20590,  between 9 a.m.  and 5 p.m.,  Monday through Friday,
except Federal holidays.

EXAMINING THE AD DOCKET

You   may   examine   the   AD  docket   on   the   Internet   at  http://
www.regulations.gov;  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 this proposed  AD, 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.

FOR FURTHER INFORMATION CONTACT: Gregory Davison, Aerospace Engineer, FAA,
Small Airplane Directorate,  901 Locust, Room  301, Kansas City,  Missouri
64106; telephone: (816) 329-4130; fax: (816) 329-4090.

SUPPLEMENTARY INFORMATION:

COMMENTS INVITED

We invite you to send any written relevant data, views, or arguments about
this  proposed AD.  Send your  comments to  an address  listed  under  the
ADDRESSES  section.   Include  "Docket   No.  FAA-2010-0260;   Directorate
Identifier  2010-CE-015-AD"  at  the   beginning  of  your  comments.   We
specifically  invite  comments   on  the  overall   regulatory,  economic,
environmental, and energy  aspects of this  proposed AD. We  will consider
all comments received by the closing  date and may amend this proposed  AD
because of those comments.

We  will  post  all  comments  we  receive,  without  change,  to  http://
www.regulations.gov, including  any personal  information you  provide. We
will also  post a  report summarizing  each substantive  verbal contact we
receive about this proposed AD.

DISCUSSION

We proposed to amend 14 CFR part 39 with an earlier NPRM for the specified
products, which was  published in the  Federal Register on  March 16, 2010
(75 FR 12466). That earlier  NPRM proposed to require actions  intended to
address the unsafe condition for the products listed above.

Since that NPRM was issued, we have determined that additional actions are
necessary  in  order  to  eliminate  any  confusion  and  to  ensure pilot
awareness of the unsafe condition.  Specifically, we are adding a  placard
requirement prohibiting aerobatic flight before accomplishing the  actions
of the proposed AD. Since  these actions impose an additional  burden over
that proposed in the  NPRM, we are reopening  the comment period to  allow
the public the chance to comment on these additional actions.

RELEVANT SERVICE INFORMATION

Grob Aircraft AG has issued  Service Bulletin No. MSB1078-164, dated  July
21, 2009. The actions described  in this service information are  intended
to correct the unsafe condition identified in the MCAI.

FAA'S DETERMINATION AND REQUIREMENTS OF THE PROPOSED AD

This  product  has been  approved  by the  aviation  authority of  another
country, and is approved for  operation in the United States.  Pursuant to
our bilateral  agreement with  this State  of Design  Authority, they have
notified us  of the  unsafe condition  described in  the MCAI  and service
information  referenced  above.  We  are  proposing  this  AD  because  we
evaluated all information and  determined the unsafe condition  exists and
is likely to exist or develop on other products of the same type design.

Certain changes described above expand the scope of the earlier NPRM. As a
result, we  have determined  that it  is necessary  to reopen  the comment
period to provide additional opportunity for the public to comment on  the
proposed AD.

DIFFERENCES BETWEEN THIS PROPOSED AD AND THE MCAI OR SERVICE INFORMATION

We have reviewed the MCAI and related service information and, in general,
agree with their substance.  But we might have  found it necessary to  use
different words from those in the MCAI to ensure the AD is clear for  U.S.
operators and is enforceable. In making these changes, we do not intend to
differ substantively from the information provided in the MCAI and related
service information.

We might also have proposed different actions in this AD from those in the
MCAI in order to follow FAA policies. Any such differences are highlighted
in a NOTE within the proposed AD.

COSTS OF COMPLIANCE

We estimate that this AD will affect 3 products of U.S. registry. We  also
estimate that it would take about 3 work-hours per product to comply  with
the basic requirements of this proposed AD. The average labor rate is  $85
per work-hour.

Based on these figures,  we estimate the cost  of the proposed AD  on U.S.
operators to be $765 or $255 per product.

In addition, we estimate that  any necessary follow-on actions would  take
about 3 work-hours and require parts  costing $68, for a cost of  $323 per
product. We have  no way of  determining the number  of products that  may
need these actions.

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 proposed AD would not have federalism implications
under Executive Order 13132. This proposed AD would 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 proposed regulation:

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); and

3. 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.

We prepared a regulatory evaluation of the estimated costs to comply  with
this proposed AD and placed it in the AD docket.

LIST OF SUBJECTS IN 14 CFR PART 39

Air transportation, Aircraft, Aviation safety, Safety.

THE PROPOSED AMENDMENT

Accordingly, under the authority delegated to me by the Administrator, the
FAA proposes to amend 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: