Airworthiness Directives; Burkhart GROB Luft-und Raumfahrt GmbH Model G 109B Gliders

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-72-AD]

RIN 2120-AA64

Airworthiness Directives; Burkhart GROB Luft-und Raumfahrt GmbH

Model G 109B Gliders

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

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(AD) that would apply to all Burkhart GROB Luft-und Raumfahrt GmbH

(Grob) Model G 109B gliders. The proposed AD would require inspecting

the engine mounting frame for paint scratches and damage (abrasions,

notches, or chafing); and repairing any paint scratches, and repairing

or replacing any engine mounting frame that is found damaged. The

proposed AD is the result of mandatory continuing airworthiness

information (MCAI) issued by the airworthiness authority for Germany.

The actions specified by the proposed AD are intended to detect and

correct damage to the engine mounting frame, which could result in

failure of the engine mount structure with consequent loss of the

engine.

DATES: Comments must be received on or before October 6, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Central Region, Office of the Regional Counsel,

Attention: Rules Docket No. 98-CE-72-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 Grob-Werke GmbH & Co. KG, Unternehmensbereich, Burkhart Grob

Flugzeugbau, Flugplatz Mattsies, 86874 Tussenhausen, Germany. This

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

above.

FOR FURTHER INFORMATION CONTACT: Mr. Mike Kiesov, Aerospace Engineer,

FAA, Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City,

Missouri 64106; telephone: (816) 426-6932; facsimile: (816) 426-2169.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the

proposed rule by submitting such written data, views, or arguments as

they may desire. Communications should identify the Rules Docket number

and be submitted in triplicate to the address specified above. All

communications received on or before the closing date for comments,

specified above, will be considered before taking action on the

proposed rule. The proposals contained in this notice may be changed in

light of the comments received.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the proposed rule. All

comments submitted will be available, both before and after the closing

date for comments, in the Rules Docket for examination by interested

persons. A report that summarizes each FAA-public contact concerned

with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this notice must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket No. 98-CE-72-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 Regional Counsel, Attention:

Rules Docket No. 98-CE-72-AD, Room 1558, 601 E. 12th Street, Kansas

City, Missouri 64106.

Discussion

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

for Germany, notified the FAA that an unsafe condition may exist on all

Grob G 109B gliders. The LBA reports several incidents of paint

scratches and damage (abrasions, notches, or chafing) on the above-

referenced gliders. This damage is parallel to tube #3 of the engine

mounting frame. The steel spiral of the warm air duct that is running

from the heat exchanger to the left-hand carburetor is rubbing on the

engine mounting frame and causing this damage.

This condition, if not detected and corrected, could result in

failure of the engine mount structure with consequent loss of the

engine.

Relevant Service Information

Grob has issued Service Bulletin TM 817-45, dated July 27, 1995,

which specifies procedures for inspecting the engine mounting frame for

paint scratches and damage (abrasions, notches, or chafing). This

service bulletin also specifies repairing paint scratches; and sending

any engine mounting frame that is damaged to the manufacturer for

repair.

The LBA classified this service bulletin as mandatory and issued

German AD 95-362 Grob, dated September 27, 1995, in order to assure the

continued airworthiness of these gliders in Germany.

The FAA's Determination

This glider 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, including the service information referenced

above; 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 109B gliders of the same type design

registered in the United States, the FAA is proposing AD action. The

proposed AD would require inspecting the engine mounting frame for

paint scratches and damage (abrasions, notches, or chafing); and

repairing any paint scratches, and repairing or replacing any engine

mounting frame that is found damaged. Accomplishment of the proposed

actions would be required in accordance with Grob Service Bulletin TM

817-45, dated July 27, 1995.

Cost Impact

The FAA estimates that 29 gliders in the U.S. registry would be

affected by the proposed inspection, that it would take approximately 2

workhours per airplane to accomplish the proposed inspection, and that

the average labor rate is approximately $60 an hour. Based on these

figures, the total cost impact of the proposed inspection on U.S.

operators is estimated to be $3,480, or $120 per glider.

If damage is found on the engine mounting frame that is beyond

certain limits specified in the service information, the FAA estimates

that it would take approximately 13 workhours per glider to accomplish

the proposed repair or replacement, at an average labor rate of

approximately $60 an hour. Parts cost $200 for repair and $750 for

replacement. Based on these figures, the total cost impact of the

proposed repair, if necessary, is estimated to be $980 per glider. The

total cost impact of the proposed replacement, if necessary, is

estimated to be $1,530 per glider.

Compliance Time of This AD

Although damage to the engine mounting frame occurs during flight,

this unsafe condition is not a result of the number of times the glider

is operated. The chance of this situation

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occurring is the same for a glider with 10 hours time-in-service (TIS)

as it would be for a glider with 500 hours TIS. For this reason, the

FAA has determined that a compliance based on calendar time should be

utilized in this proposed AD in order to assure that the unsafe

condition is addressed on all gliders in a reasonable time period.

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, 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

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 airworthiness directive

(AD) to read as follows:

Burkhart GROB Luft-und Raumfahrt GMBH: Docket No. 98-CE-72-AD.

Applicability: Model G 109B gliders, all serial numbers,

certificated in any category.

Note 1: This AD applies to each glider 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 gliders 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 (d) 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.

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

already accomplished.

To detect and correct damage to the engine mounting frame, which

could result in failure of the engine mount structure with

consequent loss of the engine, accomplish the following:

(a) Within the next 3 calendar months after the effective date

of this AD, inspect the engine mounting frame for paint scratches

and damage (abrasions, notches, or chafing) in accordance with the

Action section of Grob Service Bulletin TM 817-45, dated July 27,

1995.

(b) If a paint scratch(es) is found during the inspection

required by paragraph (a) of this AD, prior to further flight,

remove all flakes and dust from the area, degrease the tube and

apply a protective anti-corrosion coat, and shorten the warm air

duct or replace it if damaged. Accomplish the warm air duct

modification or replacement in accordance with the maintenance

manual.

(c) If damage (abrasions, notches, or chafing) is found during

the inspection required by paragraph (a) of this AD, and the damage

is 0.7 millimeters (mm) or less in depth as specified in paragraph

3(b) of the Action section of Grob Service Bulletin TM 817-45, dated

July 27, 1995, prior to further flight, degrease the tube and apply

a protective anti-corrosion coat, and shorten the warm air duct or

replace it if damaged. Accomplish the warm air duct modification or

replacement in accordance with the maintenance manual. Within 6

calendar months after the inspection required by paragraph (a) of

this AD, accomplish one of the following:

(1) Send the engine mounting frame to the manufacturer for

repair at the address specified in paragraph (g) of this AD and

accomplish the warm air duct modification or replacement specified

in paragraph (b) of this AD. Do not operate the glider until the

part is repaired, sent back, and re-installed on the glider; or

(2) Replace the engine mounting frame with a new part of the

same design, or an FAA-approved part that has been inspected in

accordance with the requirements of paragraph (a) of this AD and is

found free of damage.

(d) If damage (abrasions, notches, or chafing) is found during

the inspection required by paragraph (a) of this AD, and the damage

is more than 0.7 mm in depth as specified in paragraph 3(c) of the

Action section of Grob Service Bulletin TM 817-45, dated July 27,

1995, prior to further flight, accomplish one of the following:

(1) Send the engine mounting frame to the manufacturer for

repair at the address specified in paragraph (g) of this AD and

accomplish the warm air duct modification or replacement specified

in paragraph (b) of this AD. Do not operate the glider until the

part is repaired, sent back, and re-installed on the glider; or

(2) Replace the engine mounting frame with a new part of the

same design, or an FAA-approved part that has been inspected in

accordance with the requirements of paragraph (a) of this AD and is

found free of damage. Accomplish the warm air duct modification or

replacement specified in paragraph (b) of this AD

(e) Special flight permits may be issued in accordance with

Secs. 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.

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

compliance times that provides an equivalent level of safety may be

approved by the Manager, Small Airplane Directorate, 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.

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.

(g) Questions or technical information related to Grob Service

Bulletin TM 817-45, dated July 27, 1995, should be directed to Grob-

Werke GmbH & Co. KG, Unternehmensbereich, Burkhart Grob Flugzeugbau,

Flugplatz Mattsies, 86874 Tussenhausen, Germany. This service

information may be examined at the FAA, Central Region, Office of

the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City,

Missouri 64106.

Note 3: The subject of this AD is addressed in German AD 95-362

Grob, dated September 27, 1995.

Issued in Kansas City, Missouri, on August 27, 1998.

James E. Jackson,

Acting Manager, Small Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 98-23616 Filed 9-1-98; 8:45 am]

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