Airworthiness Directives; Burkhart Grob, Luft- und Raumfahrt, Model G 103 C Twin III SL Sailplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-CE-37-AD]

RIN 2120-AA64

Airworthiness Directives; Burkhart Grob, Luft- und Raumfahrt,

Model G 103 C Twin III SL Sailplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive

(AD) that would apply to the Burkhart Grob, Luft- und Raumfahrt (Grob)

Model G 103 C Twin III SL sailplanes. The proposed action would require

inspecting the propeller bearing and upper pulley wheel for increased

play and, if increased play is found, modifying the propeller bearing

and pulley wheel with a part of improved design. The proposed action is

prompted by two reports of Model G 103 C Twin III SL sailplanes losing

the engine propeller while in flight and one operator finding increased

play in the sailplane propeller during an inspection. The actions

specified by the proposed AD are intended to prevent the loss of the

sailplane engine propeller and possibly causing loss of the sailplane.

DATES: Comments must be received on or before April 3, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Central Region, Office of the Assistant Chief

Counsel, Attention: Rules Docket No. 96-CE-37-AD, Room 1558, 601 E.

12th Street, Kansas City, Missouri 64106. Comments may be inspected at

this location between 8 a.m. and 4 p.m., Monday through Friday,

holidays excepted.

Service information that applies to the proposed AD may be obtained

from Burkhart Grob Luft und Raumfahrt, D-86874 Mattsies, Germany. This

information also may be examined at the Rules Docket at the address

above.

FOR FURTHER INFORMATION CONTACT: Mr. J. Mike Kiesov, Project Officer,

Sailplanes, Small Airplane Directorate, Airplane Certification Service,

FAA, 1201 Walnut, suite 900, Kansas City, Missouri, 64106; telephone

nts

to Docket No. 96-CE-37-AD.'' The postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request

to the FAA, Central Region, Office of the Assistant Chief Counsel,

Attention: Rules Docket No. 96-CE-37-AD, Room 1558, 601 E. 12th Street,

Kansas City, Missouri 64106.

Events Leading to the Proposed Action

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority

for Germany, recently notified the FAA that an unsafe condition may

exist on certain Grob Model G 103 C Twin III SL sailplanes, serial

numbers (S/N) 35002 through 35051. The LBA reports that two Model G 103

C Twin III SL sailplanes lost the engine propeller while in flight, and

one operator found increased play in the sailplane propeller bearing

and upper pulley wheel during an inspection. Increased play is defined

by measuring the movement at the outer edge of the brake disc. If the

movement exceeds or is equal to 0.4 mm, then the outer bearing and

upper pulley wheel would need to be replaced. This increased play could

start rotating the outer bearing races and damage the grooved nut,

subsequently causing the engine propeller to come loose and possibly

fall off. This condition, if not detected and corrected, could result

in loss of the sailplane.

Grob has issued Service Bulletin (SB) 869-18, dated March 7, 1996,

and SB 869-18/2, dated July 8, 1996, that revises page six of SB 869-

18, which specifies inspecting the propeller bearing for increased play

and modifying the propeller bearing, if increased play is found.

FAA's Determination

ibly

fall off. This condition, if not detected and corrected, could result

in loss of the sailplane.

Grob has issued Service Bulletin (SB) 869-18, dated March 7, 1996,

and SB 869-18/2, dated July 8, 1996, that revises page six of SB 869-

18, which specifies inspecting the propeller bearing for increased play

and modifying the propeller bearing, if increased play is found.

FAA's Determination

This sailplane model is manufactured in Germany and is type

certificated for operation in the United States under the provisions of

section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and

the applicable bilateral airworthiness agreement. Pursuant to this

bilateral airworthiness agreement, the LBA has kept the FAA informed of

the situation described above. The FAA has examined the findings of the

LBA, reviewed all available information, and determined that AD action

is necessary for products of this type design that are certificated for

operation in the United States.

Explanation of the Provisions of the Proposed AD

Since an unsafe condition has been identified that is likely to

exist or develop in other Grob G 103 C Twin III SL sailplanes of the

same type design, the proposed AD would require repetitively inspecting

the propeller bearing and pulley wheel for increased play, eventually

modifying the propeller bearing and upper pulley wheel by installing a

part of improved design.

Related Service Information

Accomplishment of the proposed action would be in accordance with

Grob Service Bulletin (SB) 869-18, dated March 7, 1996, and Grob SB

869-18/2, dated July 8, 1996, which is a

revised page 6 of the Grob SB 869-18, dated March 7, 1996.

Cost Impact

ased play, eventually

modifying the propeller bearing and upper pulley wheel by installing a

part of improved design.

Related Service Information

Accomplishment of the proposed action would be in accordance with

Grob Service Bulletin (SB) 869-18, dated March 7, 1996, and Grob SB

869-18/2, dated July 8, 1996, which is a

revised page 6 of the Grob SB 869-18, dated March 7, 1996.

Cost Impact

The FAA estimates that 8 sailplanes in the U.S. registry would be

affected by the proposed AD, that it would take approximately 1 hour

per sailplane to accomplish the proposed initial inspection and that

the average labor rate is approximately $60 an hour. The estimated cost

for the initial inspection would be $60 per sailplane. Based on this

figure, the total cost impact of the proposed AD on U.S. operators is

estimated to be $480.

Grob has informed the FAA that no parts have been distributed to

equip any sailplane in the United States. The FAA has no way of

determining how many owners/operators may have incorporated the

proposed action on their sailplane.

Regulatory Impact

The regulations proposed herein would not have substantial direct

effects on the States, on the relationship between the national

government and the States, 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

proposal would 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;

er and

responsibilities among the various levels of government. Therefore, in

accordance with Executive Order 12612, it is determined that this

proposal would 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) if promulgated,

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. A copy of the draft regulatory evaluation

prepared for this action has been placed 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, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration proposes to amend

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 AD to read as follows:

Burkhardt Grob: Docket No. 96-CE-37-AD.

Applicability: Model G 103 C Twin III SL sailplanes (serial

numbers 35002 through 35051, including gliders), certificated in any

category.

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 AD to read as follows:

Burkhardt Grob: Docket No. 96-CE-37-AD.

Applicability: Model G 103 C Twin III SL sailplanes (serial

numbers 35002 through 35051, including gliders), certificated in any

category.

Note 1: This AD applies to each sailplane 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 sailplanes that have been modified,

altered, or repaired so that the performance of the requirements of

this AD is affected, the owner/operator must use the authority

provided in paragraph (d) of this AD to request approval from the

FAA. This approval may address either no action, if the current

configuration eliminates the unsafe condition, or different actions

necessary to address the unsafe condition described in this AD. Such

a request should include an assessment of the effect of the changed

configuration on the unsafe condition addressed by this AD. In no

case does the presence of any modification, alteration, or repair

remove any sailplane from the applicability of this AD.

Compliance: Required as indicated in the body of this AD, unless

already accomplished.

To prevent the loss of the sailplane engine propeller and

possibly causing loss of the sailplane, accomplish the following:

guration on the unsafe condition addressed by this AD. In no

case does the presence of any modification, alteration, or repair

remove any sailplane from the applicability of this AD.

Compliance: Required as indicated in the body of this AD, unless

already accomplished.

To prevent the loss of the sailplane engine propeller and

possibly causing loss of the sailplane, accomplish the following:

(a) Within the next 5 engine operating hours do one of the

following:

(1) Modify the propeller bearing and upper pulley wheel by

installing parts of improved design in accordance with the

``Actions: 2.'' and the ``Installation Instructions'' sections of

Grob service bulletin (SB) 869-18, dated March 7, 1996, and Grob SB

869-18/2, dated July 8, 1996; or,

(2) Inspect the propeller bearing and upper pulley wheel for

increased play (movement that exceeds or is equal to 0.4 mm) in

accordance with the ``Actions'' section of Grob service bulletin

(SB) 869-18, dated March 7, 1996.

(i) If increased play is found, prior to further flight,

accomplish the modification in paragraph (a)(1) of this AD or,

(ii) If no increased play is found, continue to repetitively

inspect for increased play in the propeller bearing and upper pulley

wheel every 5 engine operating hours in accordance with the

``Actions: 1.'' section in Grob SB 869-18, dated March 7, 1996, and

Grob SB 869-18/2, dated July 8, 1996. If increased play is found

during any inspection, then, prior to further flight, accomplish the

modifications in paragraph (a)(1) of this AD.

(b) Accomplishing the modification in paragraph (a)(1) of this

AD is a terminating action to the repetitive inspection required in

paragraph (a)(2)(ii) of this AD.

(c) 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 sailplane to a location where

the requirements of this AD can be accomplished.

hing the modification in paragraph (a)(1) of this

AD is a terminating action to the repetitive inspection required in

paragraph (a)(2)(ii) of this AD.

(c) 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 sailplane to a location where

the requirements of this AD can be accomplished.

(d) An alternative method of compliance or adjustment of the

initial and repetitive compliance time that provides an equivalent

level of safety may be approved by the Manager, Small Airplane

Directorate, FAA, 1201 Walnut, suite 900, Kansas City, Missouri,

64106. The request shall be forwarded through an appropriate FAA

Maintenance Inspector, who may add comments and then send it to the

Manager, Small Airplane Directorate, FAA, 1201 Walnut, suite 900,

Kansas City, Missouri, 64106.

Note 2: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Small Airplane Directorate.

(e) All persons affected by this directive may obtain copies of

the document referred to herein upon request to Burkhart Grob

Luftund Raumfahrt, D-86874 Mattsies, Germany; or may examine this

document at the FAA, Central Region, Office of the Assistant Chief

Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Issued in Kansas City, Missouri, on January 22, 1997.

Henry A. Armstrong,

Acting Manager, Small Airplane Directorate, Aircraft Certification

Service.

[FR DOC. 97-2104 Filed 1-28 97; 8:45 am]

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