AD 2000-04-16

This amendment adopts a new airworthiness directive (AD) that applies to all Alexander Schleicher Segelflugzeugbau (Alexander Schleicher) Models ASH 25M and ASH 26E sailplanes. This AD requires that you accomplish the following:

- check to see if the sailplane has a muffler marked with an X on the front plate;

- accomplish pre-flight checks on the carbon reinforced plastic fairing for signs of overheat traces and/or perform boroscope inspections, depending on the number of sailplane hours accumulated; and

- replace the muffler with an improved design muffler either at a certain time period or immediately if discrepancies are found during any inspection. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. The actions specified by this AD are intended to prevent excessive radiation from causing the carbon fiber shroud on the engine muffler to delaminate. The carbon fiber shroud serves the same function as a firewall and delamination could cause a fire to spread throughout the sailplane.

Final rule; request for comments

2000-04-16 ALEXANDER SCHLEICHER SEGELFLUGZEUGBAU: Amendment 39-11599; Docket No. 99-CE-78-AD.

(a) What sailplanes are affected by this AD?: Models ASH 25M and ASH 26E sailplanes, all serial numbers, certificated in any category.

(b) Who must comply with this AD?: Anyone who wishes to operate any of the above sailplanes on the U.S. Register.

(c) What problem does this AD address?: The actions specified by this AD are intended to prevent excessive radiation from causing the carbon fiber shroud on the engine muffler to delaminate. The carbon fiber shroud serves the same function as a firewall and delamination could cause a fire to spread throughout the sailplane.

(d) What procedures must be used to accomplish the actions of this AD?: You should use the procedures in whichever of the following (referred to as service information in the rest of this document), as applicable:

(1) Alexander Schleicher ASH 25 M Technical Note No. 15, dated September 3, 1999; or
(2) Alexander Schleicher ASH 26 E Technical Note No. 8, dated August 23, 1999.

(e) What must I do to address this problem?: Within the next 30 calendar days after the effective date of this AD, determine whether the sailplane has a muffler marked with an X on the front plate, and then accomplish the following, as applicable:

IF
THEN
The muffler front plate does not have an X on the front plate and the engine operating time is less than 40 hours time-in-service (TIS),
1. Within 30 calendar days after the effective date of this AD, accomplish a preflight inspection on the carbon fiber reinforced plastic fairing for any signs of overheat traces.
2. Upon accumulating 40 hours TIS on the engine and thereafter at intervals not to exceed 2 hours TIS until accumulating 60 hours TIS, accomplish the boroscope inspection specified in the service information.
3. Upon accumulating 60 hours TIS on the engine, replace the muffler with an improved design muffler obtained fromthe manufacturer, or other FAA-approved equivalent.
The muffler plate does not have an X on the front plate and the engine operating time is either 40 hours TIS or more than 40 hours TIS, but less than 60 hours TIS,
1. Within 30 calendar days after the effective date of this AD and thereafter at intervals not to exceed 2 hours TIS, until accumulating 60 hours TIS on the engine, accomplish the boroscope inspection specified in the service information.
2. Upon accumulating 60 hours TIS on the engine, replace the muffler with an improved design muffler obtained from the manufacturer, or other FAA-approved equivalent part.
The muffler plate does not have an X on the front plate and the engine operating time is either 60 hours TIS or more than 60 hours TIS,
Within 30 calendar days after the effective date of this AD, replace the muffler with an improved design muffler obtained from the manufacturer, or other FAA-approved equivalent part.
If any discrepancies are found during any preflight check or inspection required by this AD,
Prior to further flight, replace the muffler with an improved design muffler obtained from the manufacturer, or other FAA-approved equivalent part.
If the muffler has an X marked on the front plate,
Upon accumulating 100 hours TIS on the engine or within the next 30 calendar days after the effective date of this AD, whichever occurs later, replace the muffler with an improved design muffler obtained from the manufacturer, or other FAA-approved equivalent part.

(f) May the pilot accomplish any of the actions of this AD?: Yes. The owner/operator holding at least a private pilot certificate as authorized by section 43.7 of the Federal Aviation Regulations (14 CFR 43.7) may accomplish the check to determine whether an X is marked on the engine muffler front plate and the preflight inspection. You must make an entry into the aircraft records that shows compliance with these portions of the AD, in accordance with section 43.9 of the Federal Aviation Regulations (14 CFR 43.9).

(g) Can I comply with this AD in any other way?: Yes.

(1) You may use an alternative method of compliance or adjust the compliance time if:

(i) Your alternative method of compliance provides an equivalent level of safety; and
(ii) The Manager, Small Airplane Directorate, approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate.

(2) 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 request approval for an alternative method of compliance in accordance with paragraph (g)(1) 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 you have not eliminated the unsafe condition, specific actions you propose to address it.

(h) Where can I get information about any already-approved alternative methods of compliance?: Contact the Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4121; facsimile: (816) 329-4091.

(i) What if I need to fly the sailplane to another location to comply with this AD?: The FAA can issue a special flight permit under sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate your sailplane to a location where you can accomplish the requirements of this AD.

(j) Who should I contact if I have questions regarding the service information?: Questions or technical information related to Alexander Schleicher ASH 25 M Technical Note No. 15, dated September 3, 1999, and Alexander Schleicher ASH 26 E Technical Note No. 8, dated August 23, 1999, should be directed to Alexander Schleicher GmbH & Co. Segelflugzeugbau, D-36161 Poppenhausen, Federal Republic of Germany; telephone: ++ 49 6658 89-0; facsimile: ++ 49 6658 89-40. This service information may be examined at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

(k) Are any service bulletins incorporated into this AD by reference?: Yes. The actions required by this AD must be done in accordance with Alexander Schleicher ASH 25 M Technical Note No. 15, dated September 3, 1999, and Alexander Schleicher ASH 26 E Technical Note No. 8, dated August 23, 1999. The Director of the Federal Register approved this incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 51. You can get copies from Alexander Schleicher GmbH & Co. Segelflugzeugbau, D-36161 Poppenhausen, Federal Republic of Germany. You can look at copiesat the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

(l) Has the airworthiness authority for the State of Design addressed this action?: Yes. The subject of this AD is addressed in German AD 1999-376, dated December 2, 1999, and German AD 1999-311, dated September 8, 1999.

(m) When does this amendment become effective?: This amendment becomes effective on March 20, 2000.

Discussion
What events have caused this AD?: 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 Models ASH 25M and ASH 26E sailplanes. The LBA advises that the current design engine mufflers could be defective. Specifically, excessive temperature radiation could cause the carbon fiber shroud to delaminate.

What are the consequences if the condition is not corrected?: The carbon fiber shroud serves the same function as a firewall and delamination could cause a fire to spread throughout the sailplane.

What is the cause of the problem?: Design of the engine muffler.

Relevant Service Information
Is there service information that applies to this subject?: Yes. Alexander Schleicher has issued the following service information:

- ASH 25 M Technical Note No. 15, dated September 3, 1999; and
- ASH 26 E Technical Note No. 8, dated August 23, 1999.

What are the provisions of this service bulletin?: The service bulletin specifies and/or includes procedures for:

- checking to see if the sailplane has a muffler marked with an X on the front plate;
- accomplishing pre-flight checks on the carbon reinforced plastic fairing for signs of overheat traces and/or performing boroscope inspections, depending on the number of sailplane hours accumulated; and
- replacing the muffler with an improved design muffler either at a certain time period or immediately if discrepancies are found during any inspection.

The Foreign Airworthiness Authority's Action
What action did the LBA take?: The LBA classified these service bulletins as mandatory and issued the following in order to assure the continued airworthiness of these sailplanes in Germany:

- German AD 1999-376, dated December 2, 1999; and
- German AD 1999-311, dated September 8, 1999.

Was this in accordance with the bilateral airworthiness agreement?: Yes. These sailplane models are manufactured in Germany and are 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's Determination and an Explanation of the Provisions of the AD
What has the FAA decided: After examining the circumstances and reviewing all available information related to the incidents described above including that received from the LBA, the FAA has determined that:

- an unsafe condition exists or could develop on all Alexander Schleicher Models ASH 25M and ASH 26E sailplanes;
- the actions of the above-referenced service bulletin should be accomplished on the affected sailplanes; and
- AD action should be taken in order to prevent excessive radiation from causing the carbon fiber shroud on the engine muffler to delaminate. The carbon fiber shroud serves the same function as a firewall and delamination could cause a fire to spread throughout the sailplane.

What does this AD require?: This AD requires you to accomplish the following:

- check to see if the sailplane has a muffler marked with an X on the front plate;
- accomplish pre-flight checks on the carbon reinforced plastic fairing for signs of overheat traces and/or perform boroscope inspections, depending on the number of sailplane hours accumulated; and
- replace the muffler with an improved design muffler either at a certain time period or immediately if discrepancies are found during any inspection.

Compliance Time of This AD
What is the compliance time of this AD?: The initial actions of this AD are required "within 30 calendar days after the effective date of this AD."

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for public prior comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Why is the compliance in calendar time instead of hours time-in-service?: We have established the compliance in calendar time instead of hours time-in-service (TIS) because the unsafe condition described by this AD is not directly related to sailplane operation. 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. A calendar time for compliance will assure that the unsafe condition is addressed on all sailplanes in a reasonable time period.

Why is the compliance time of this AD different than the German AD and the service information?: The service information specifies the check required in this AD "prior to further flight" and the German AD mandates this check "priorto further flight" for sailplanes registered for operation in Germany. We do not have justification for requiring the check prior to further flight. Instead, we have determined that 30 calendar days is a reasonable time period for you to accomplish this check.

Comments Invited
Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, the FAA invites comments on this rule. You may submit whatever written data, views, or arguments you choose. You need to include the rule's docket number and submit your comments in triplicate to the address specified under the caption "ADDRESSES." The FAA will consider all comments received on or before the closing date. We may amend this rule in light of comments received. Factual information that supports your ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether we need to take additional rulemaking action.

The FAA is re-examining the writing style we currently use in regulatory documents, in response to the Presidential memorandum of June 1, 1998. That memorandum requires federal agencies to communicate more clearly with the public. We are interested in your comments on whether the style of this document is clearer, and any other suggestions you might have to improve the clarity of FAA communications that affect you. You can get more information about the Presidential memorandum and the plain language initiative at http://www.plainlanguage.gov.

The FAA specifically invites comments on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. You may examine all comments we receive before and after the closing date of the rule in the Rules Docket. We will file a report in the Rules Docket that summarizes each FAA contact with the public that concerns the substantive parts of this AD.

If you want us to acknowledge the receipt of your comments, you must include a self-addressed, stamped postcard. On the postcard, write "Comments to Docket No. 99-CE-78-AD." We will date stamp and mail the postcard back to you.

Regulatory Impact
These regulations will 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. Therefore, the FAA has determined that this final rule does not have federalism implications under Executive Order 13132.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a significant regulatory action under Executive Order 12866. We determined that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If the FAA determines that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, we will prepare a final regulatory evaluation and place it in the Rules Docket (otherwise, an evaluation is not required). You may obtain a copy of this evaluation, if filed, from the Rules Docket.

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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.

39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: