Airworthiness Directives; Schempp-Hirth Cirrus and Cirrus VTC Sailplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-CE-17-AD]

Airworthiness Directives; Schempp-Hirth Cirrus and Cirrus VTC

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 Schempp-Hirth Cirrus and Cirrus VTC

sailplanes. The proposed action would require modifying the airbrake

actuating lever and replacing the airbrake system coupling balls.

Reports of the coupling balls on the airbrake actuating lever breaking

at the threaded end on several of the above-referenced sailplanes

prompted the proposed action. The actions specified by the proposed AD

are intended to prevent airbrake system failure caused by the above

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

sailplane controllability problems.

DATES: Comments must be received on or before February 28, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Counsel, Attention: Rules Docket No. 94-CE-17-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 Schempp-Hirth Flugzeubau GmbH, Krebenstr. 25, D-7312 Kirchheim/

Teck, Germany. This information may also be examined at the Rules

Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Herman C. Belderok, Project

Officer, Small Airplane Directorate, Airplane Certification Service,

FAA, 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. 94-CE-17-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. 94-CE-17-AD, Room 1558, 601 E. 12th Street,

Kansas City, Missouri 64106.

Discussion

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

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

exist on Schempp-Hirth Cirrus and Cirrus VTC sailplanes. The LBA

advises that the coupling balls on the airbrake actuating lever located

inside the fuselage have broken at the threaded end on several of the

above referenced sailplanes. This condition, if not detected and

corrected, could result in sailplane controllability problems.

Schempp-Hirth has issued Technical Note 265-10, dated November 5,

1992, which specifies procedures for modifying the airbrake actuating

lever and replacing the airbrake system coupling balls. The LBA

classified this technical note as urgent in order to assure the

continued airworthiness of these airplanes in Germany.

This airplane 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.

Since an unsafe condition has been identified that is likely to

exist or develop in other Schempp-Hirth Cirrus and Cirrus VTC

sailplanes of the same type design, the proposed AD would require

modifying the airbrake actuating lever and replacing the airbrake

system coupling balls. The proposed actions would be accomplished in

accordance with the service information referenced above.

The FAA estimates that 21 sailplanes in the U.S. registry would be

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

workhour per sailplane to accomplish the proposed action, and that the

average labor rate is approximately $60 an hour. Parts cost

approximately $25 per airplane. Based on these figures, the total cost

impact of the proposed AD on U.S. operators is estimated to be $1,785.

This figure is based on the assumption that no affected sailplane

owner/operator has accomplished the proposed modification and

replacement. The FAA believes that several of the 21 affected sailplane

owners/operators have already accomplished the proposed action, which

would reduce the FAA's proposed cost impact upon the public.

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. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding a new AD to read as follows:

Schempp-Hirth: Docket No. 94-CE-17-AD.

Applicability: Cirrus and Cirrus VTC Sailplanes, certificated in

any category.

Compliance: Required upon the accumulation of 500 hours time-in-

service (TIS) or within the next 20 hours TIS after the effective

date of this AD, whichever occurs later, unless already

accomplished.

To prevent airbrake system failure caused by broken coupling

balls on the airbrake actuating lever, which, if not detected and

corrected, could result in sailplane controllability problems,

accomplish the following:

(a) Modify the airbrake actuating lever and replace the airbrake

system coupling balls (located on the actuating lever) in accordance

with Schempp-Hirth Technical Note No. 265-10, dated November 5,

1992.

(b) 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 airplane to a location where

the requirements of this AD can be accomplished.

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

initial or repetitive compliance times that provides an equivalent

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

Directorate, Aircraft Certification Service, 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.

Note: Information concerning the existence of approved

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

obtained from the Small Airplane Directorate.

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

the document referred to herein upon request to Schempp-Hirth

Flugzeubau GmbH, Krebenstr. 25, D-7312 Kirchheim/Teck, 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 December 14, 1994.

Barry D. Clements,

Manager, Small Airplane Directorate, Aircraft Certification Service.

[FR Doc. 94-31184 Filed 12-19-94; 8:45 am]

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