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Proposed Rule

Airworthiness Directives; Bombardier-Rotax GmbH Type 912 F, 912 S, and 914 F Series Reciprocating Engines

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Information about this document as published in the Federal Register.

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Start Preamble

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for Bombardier-Rotax GmbH Type 912 F, 912 S, and 914 F series reciprocating engines. That AD currently requires venting of the lubrication system and inspection of the valve train on all engines. That AD also requires venting of the lubrication system of all engines on which the lubrication system has been opened, and any engine on which the propeller has been rotated one full turn in the wrong direction. This proposed AD would require similar actions, and also require removing the existing part number oil dipstick from service and installing a new oil dipstick. This proposed AD results from the need to clarify the mandated procedures for inspections and venting. This proposed AD also results from the manufacturer discovering that under certain circumstances, the oil level in the oil tank can fall below the minimum level required to sustain proper engine lubrication. We are proposing this AD to prevent damage to the engine valve train due to inadequate venting of the lubrication system, which can result in an in-flight engine failure and forced landing.

DATES:

We must receive any comments on this proposed AD by October 12, 2004.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD:

  • By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2002-NE-33-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
  • By fax: (781) 238-7055.
  • By e-mail: 9-ane-adcomment@faa.gov.

You can get the service information identified in this proposed AD from Bombardier-Rotax GmbH, Gunskirchen, Start Printed Page 49830Austria; telephone 7246-601-423; fax 7246-601-760.

You may examine the AD docket at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Richard Woldan, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park; telephone (781) 238-7136; fax (781) 238-7199.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2002-NE-33-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it; we will date-stamp your postcard and mail it back to you. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. If a person contacts us verbally, and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications that affect you. You may get more information about plain language at http://www.faa.gov/​language and http://www.plainlanguage.gov.

Examining the AD Docket

You may examine the AD Docket (including any comments and service information), by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. See ADDRESSES for the location.

Discussion

On October 17, 2002, we issued AD 2002-21-16, Amendment 39-12923 (67 FR 65033, October 23, 2002). That AD requires:

  • Before further flight, inspecting the engine valve train, venting the lubrication system, and inspecting for the correct venting of the oil system.
  • Thereafter, before engine start, properly venting the lubrication system after initial installation of a new or overhauled engine, after opening the oil system, after an engine oil change, and after the propeller was rotated one full turn in the wrong direction of rotation, allowing air to be ingested into the valve train components.

Austro Control, which is the airworthiness authority for Austria, notified us that an unsafe condition may exist on Bombardier-Rotax GmbH 912 F, 912 S, and 914 F series reciprocating engines. Austro Control advised that there have been seven in-flight engine failures that occurred within 50 hours time-in-service (TIS) after installation of a new or overhauled engine. Investigations by Austro Control indicate that the failures were due to inadequate venting of the lubrication systems. Inadequate venting of the lubrication system can cause damage to the engine valve train as a result of compression of trapped air while at maximum camshaft speed resulting in high impact stresses to valve train components.

Actions After AD 2002-21-16 Was Issued

After AD 2002-21-16 was issued, Austro Control advised that there have been 11 in-flight engine failures due to an oil tank level that is too low causing induction of air into the oil system and higher than anticipated pressures through the valve push rods. Investigations by Austro Control indicate that the failures were due to slower than anticipated return of oil from the engine crankcase back to the oil tank. Changes to the viscous properties of the oil cause a slower return of oil to the oil tank. This slow return results in the oil level in the oil tank falling below the minimum level required. An oil level that is too low causes induction of air into the oil system and higher than anticipated pressures through the valve push rods. That higher pressure causes damage to the components of the engine valve train. To help prevent this condition, Rotax introduced a new engine oil dipstick that has higher level indicator marks, which requires a greater quantity of oil in the oil tank. This increased quantity of oil helps prevent the induction of air into the oil system.

Also, after AD 2002-21-16 was issued, we found that some corrections and clarifications are required. In the ADDRESSES paragraph, this proposal corrects the address and telephone numbers for the Rotax service information. Also, this proposal revises the compliance section for clarification of the inspections and venting to more closely match the related Austro Control AD.

Relevant Service Information

We have reviewed and approved the technical contents of Bombardier-Rotax GmbH Mandatory Service Bulletin (MSB) No. SB-912-036/SB-914-022, Revision 1, dated August 2002. This MSB provides procedures for inspecting engines for correct venting of the oil system and procedures for inspecting the valve train for damage caused by inadequate venting. Austro Control has classified this service bulletin as mandatory and issued AD No.113R1 in order to assure the airworthiness of these Bombardier-Rotax GmbH engines in Austria.

Differences Between the Proposed AD and the Service Information

Bombardier-Rotax GmbH MSB SB-912-036/SB-914-022 allows up to 5 hours TIS before venting and inspecting for correct venting of the oil system on engines with 50 hours or less TIS since the lubrication system has been opened and drained, since an oil change was performed using improper procedures, or since the propeller was rotated more than one turn in the wrong direction of rotation. We have determined that the venting and inspecting of the valve train must be done before the next engine start.

Bilateral Agreement Information

This engine model is manufactured in Austria 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. In keeping with this bilateral airworthiness agreement, Austro Control has kept us informed of the situation described above. We have examined the findings of Austro Control, 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.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. Therefore, we are proposing this AD, which would require:

  • Before the next engine start for engines with 50 hours or less TIS on the effective date of the AD, since the engine had the oil system opened, or the oil was changed using other than Start Printed Page 49831specified procedures, or the propeller was rotated more than one turn in the wrong direction of rotation, inspecting for valve train damage, properly venting the lubrication system and inspecting for the correct venting of the hydraulic valve tappets.
  • Thereafter, for all engines, before engine start, properly venting the lubrication system after initial installation of a new or overhauled engine, after opening the oil system, after changing the oil using improper procedures, or after the propeller was rotated more than one turn in the wrong direction of rotation, allowing air to be ingested into the valve train components.
  • At the next oil change, or within 100 hours TIS after the effective date of the AD, whichever is later, removing the oil dipstick, part number (P/N) 956150, from service, and installing a serviceable dipstick that has a different P/N.

The proposed AD would require that you do the venting of the lubrication system using the service information described previously.

Costs of Compliance

There are about 624 Bombardier-Rotax GmbH Type 912 F, 912 S, and 914 F series reciprocating engines of the affected design in the worldwide fleet. We estimate that 282 engines installed on aircraft of U.S. registry would be affected by this proposed AD. We also estimate that it would take about one work hour per engine to perform one oil system inspection and venting, and that the average labor rate is $65 per work hour. Required parts would cost about $0.85 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $18,570.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.

For the reasons discussed above, I certify that the proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

3. Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a summary of the costs to comply with this proposal and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2002-NE-33-AD” in your request.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. The Federal Aviation Administration (FAA) amends § 39.13 by removing Amendment 39-12923 (67 FR 65033, October 23, 2002) and by adding a new airworthiness directive, to read as follows:

Bombardier-Rotax GmbH: Docket No. 2002-NE-33-AD. Supersedes AD 2002-21-16, Amendment 39-12923.

Comments Due Date

(a) The FAA must receive comments on this airworthiness directive (AD) action by October 12, 2004.

Affected ADs

(b) This AD supersedes AD 2002-21-16, Amendment 39-12923.

Applicability

(c) This AD applies to Bombardier-Rotax GmbH 912 F, 912 S, and 914 F series reciprocating engines. These engines are installed on, but not limited to, Diamond Aircraft Industries, DA20-A1, Diamond Aircraft Industries GmbH Model HK 36 TTS, Model HK 36TTC, and Model HK 36 TTC-ECO, Iniziative Industriali Italiane S.p.A. Sky Arrow 650 TC and Sky Arrow 650 TCN, Aeromot-Industria Mecanico Metalurgica ltda., Models AMT-300 and AMT-200S, and Stemme S10-VT aircraft.

Unsafe Condition

(d) This AD results from the manufacturer discovering that under certain circumstances, the oil level in the oil tank can fall below the minimum level required to sustain proper engine lubrication. The actions specified in this AD are intended to prevent damage to the engine valve train due to inadequate venting of the lubrication system, which can result in an in-flight engine failure and forced landing.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.

Initial Venting and Inspection for Correct Venting

(f) Before the next engine start, for all Bombardier-Rotax GmbH 912 F, 912 S, and 914 F series reciprocating engines that have not been operated since doing any of the actions identified in Section 1.5 (a) of Rotax Mandatory Service Bulletin (MSB) SB-912-036/SB-914-022, Revision 1, dated August 2002, do the following:

(1) Perform venting of the lubrication system; and

(2) Perform inspection for correct venting of the hydraulic valve tappets. Use Section 3.1.1 through Section 3.1.4 of the Accomplishment Instructions of Rotax MSB SB-912-036/SB-914-022, Revision 1, dated August 2002 to do the venting and inspection.

Inspection of Engine Valve Train

(g) Before the next engine start, for all Bombardier-Rotax GmbH 912 F, 912 S, and 914 F series reciprocating engines that have been operated for 50 hours or less on the effective date of this AD since doing any of the actions identified in Section 1.5 (b) of Rotax Mandatory Service bulletin (MSB) SB-912-036/SB-914-022, Revision 1, dated August 2002, do the following:

(1) Disassemble and perform inspection of the engine valve train; and

(2) Reassemble, vent the lubrication system, and inspect for correct venting of the hydraulic valve tappets. Use Section 3.1.5 through Section 3.1.7 of the Accomplishment Instructions of Rotax MSB SB-912-036/SB-914-022, Revision 1, dated August 2002.

Repetitive Venting of the Lubrication System

(h) Thereafter, for all Bombardier-Rotax GmbH 912 F, 912 S, and 914 F series reciprocating engines, after doing any of the actions in the following paragraphs (h)(1) through (h)(4), vent the lubrication system and inspect for correct venting of the hydraulic valve tappets before starting the engine. Use Section 3.1.1 through Section 3.1.4 of the Accomplishment Instructions of Rotax MSB SB-912-036/SB-914-022, Revision 1, dated August 2002 to do the venting and inspecting.

(1) The installation of a new or overhauled engine.

(2) The oil system has been opened allowing air to enter the valve train (e.g. oil pump, oil cooler, oil suction line removed which allows oil to drain from the engine oil galleries).

(3) The engine oil was changed using procedures other than those included in Section 1.2 of Rotax MSB SB-912-036/SB-914-022 Revision 1, dated August 2002.

(4) The propeller was turned more than one turn in the wrong direction of rotation.

Removal of Existing Oil Dipstick From Service

(i) At the next oil change or within 100 hours TIS after the effective date of this AD, Start Printed Page 49832whichever is later, remove the oil dipstick, part number (P/N) 956150, from service, and install a dipstick that has a different P/N. Information on removing oil dipstick P/N 956150 from service can be found in Rotax Service Bulletin SB-912-040/SB-914-026, Revision 1, dated August 2003.

Prohibition of Oil Dipstick, P/N 956150

(j) After the effective date of this AD, do not use dipstick P/N 956150 after complying with paragraph (i) of this AD.

Alternative Methods of Compliance

(k) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Special Flight Permits

(l) Special flight permits are not permitted.

Material Incorporated by Reference

(m) None.

Related Information

(n) Austro Control airworthiness directives No. 113R1, dated August 30, 2002, and No. 116, dated September 15, 2003, Rotax Service Bulletin SB-912-040/SB-914-026, Revision 1, dated August 2003, and Rotax Service Instruction SI-04-1997, Revision 3, dated September 2002 also address the subject of this AD.

Start Signature

Issued in Burlington, Massachusetts, on August 6, 2004.

Jay J. Pardee,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 04-18440 Filed 8-11-04; 8:45 am]

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