Airworthiness Directives; Alexander Schleicher Segelflugzeugbau Model ASH 26E Sailplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

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

RIN 2120-AA64

Airworthiness Directives; Alexander Schleicher Segelflugzeugbau

Model ASH 26E 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 all Alexander Schleicher Segelflugzeugbau

(Alexander Schleicher) Model ASH 26E sailplanes. The proposed AD would

require inspecting the red silicone tube of the rotor interior air

cooling (just in front of the carburetor) for oil leaks and the heat

damping layer of the lower exhaust damper fairing for oil

contamination, and replacing the applicable parts where oil leakage or

contamination is found. 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 any oil-contaminated exhaust damper

fairing caused by oil leakage in the red silicone tube of the rotor

interior air cooling, which could result in an exhaust fire and/or an

explosion.

DATES: Comments must be received on or before February 11, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 98-CE-98-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 Alexander Schleicher GmbH & Co., Segelflugzeugbau, Postfach 60,

36163 Poppenhausen, Germany; telephone: ++49 (0) 6658-890; facsimile:

++49 (0) 6658-8923. 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-98-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

[[Page 446]]

FAA, Central Region, Office of the Regional Counsel, Attention: Rules

Docket No. 98-CE-98-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 all Alexander Schleicher Model ASH 26E sailplanes. The LBA

reports an incident where oil in the heat damping layer of the exhaust

fairing caught fire. Investigation reveals the following possible

causes of this incident:

--Oil was spilled when filling the engine oil tank; and

--Oil leakage could have occurred in the red silicone tube of the

rotor interior air cooling (just in front of the carburetor).

This condition, if not detected and corrected in a timely manner,

could result in an exhaust fire and/or an explosion.

Relevant Service Information

Alexander Schleicher has issued Technical Note No. 6, dated August

10, 1998, which specifies procedures for inspecting the red silicone

tube of the rotor interior air cooling (just in front of the carburetor

) for oil leaks and the heat damping layer of the lower exhaust damper

fairing for oil contamination.

The LBA classified this service bulletin as mandatory and issued

German AD 98-347, dated September 10, 1998, in order to assure the

continued airworthiness of these sailplanes in Germany.

The 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, 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 Alexander Schleicher Model ASH 26E sailplanes

of the same type design registered in the United States, the FAA is

proposing AD action. The proposed AD would require inspecting the red

silicone tube of the rotor interior air cooling (just in front of the

carburetor) for oil leaks and the heat damping layer of the lower

exhaust damper fairing for oil contamination, and replacing the

applicable parts where oil leakage or contamination is found.

Accomplishment of the proposed inspection would be required in

accordance with Alexander Schleicher Technical Note No. 6, dated August

10, 1998. The possible replacements would be required to be

accomplished in accordance with the applicable maintenance manual or

other applicable FAA-approved document.

Compliance Time of the Proposed AD

This unsafe condition is not a result of the number of times the

sailplane is operated. The chance of this situation occurring is the

same for a sailplane with 10 hours time-in-service (TIS) as it would be

for a sailplane with 500 hours TIS. For this reason, the FAA has

determined that a compliance based on calendar time should be utilized

in the proposed AD in order to assure that the unsafe condition is

addressed on all sailplanes in a reasonable time period.

Differences Between the German AD, the Technical Note, and This

Proposed AD

Both Alexander Schleicher Technical Note No. 6, dated August 10,

1998, and German AD 98-347, dated September 10, 1998, specify the

initial inspection prior to further flight.

The FAA does not have justification through its regulatory process

to require the inspection prior to further flight. To assure that no

affected sailplane is inadvertently grounded, the FAA is proposing a

compliance time of 1 calendar month for the initial inspection.

Cost Impact

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

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

workhour per sailplane 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 $480, or $60 per sailplane.

These figures only take into account the costs of the proposed

inspection and do not take into account the costs associated with any

parts replacement that would be necessary if oil leakage or

contamination is found. The FAA has no way of determining the number of

sailplanes that would need parts replacement because of oil leakage or

contamination.

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:

Alexander Schleicher Segelflugzeugbau: Docket No. 98-CE-98-AD.

Applicability: Model ASH 26E sailplanes, all serial numbers,

certificated in any category.

Note 1: This AD applies to each sailplane identified in the

preceding applicability

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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 request approval for an alternative method of

compliance in accordance with paragraph (c) 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 any oil-contaminated exhaust damper

fairing caused by oil leakage in the red silicone tube of the rotor

interior air cooling, which could result in an exhaust fire and/or

an explosion, accomplish the following:

(a) Within the next calendar month after the effective date of

this AD, inspect the red silicone tube of the rotor interior air

cooling (just in front of the carburetor) for oil leaks and the heat

damping layer of the lower exhaust damper fairing for oil

contamination, in accordance with the Action section of Alexander

Schleicher Technical Note No. 6, dated August 10, 1998. Prior to

further flight, replace the applicable parts where oil leakage or

contamination is found, in accordance with the applicable

maintenance manual or other applicable FAA-approved document.

(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 sailplane to a location where

the requirements of this AD can be accomplished.

(c) 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, 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 2: Information concerning the existence of approved

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

obtained from the Small Airplane Directorate.

(d) Questions or technical information related to Alexander

Schleicher Technical Note No. 6, dated August 10, 1998, should be

directed to Alexander Schleicher GmbH & Co., Segelflugzeugbau,

Postfach 60, 36163 Poppenhausen, Germany; telephone: ++49 (0) 6658-

890; facsimile: ++49 (0) 6658-8923. 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 98-347,

dated September 10, 1998.

Issued in Kansas City, Missouri, on December 29, 1998.

Marvin R. Nuss,

Acting Manager, Small Airplane Directorate,

Aircraft Certification Service.

[FR Doc. 99-42 Filed 1-4-99; 8:45 am]

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