2010-7831. Airworthiness Directives; Bombardier-Rotax GmbH Type 912 F, 912 S, and 914 F Series Reciprocating Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for certain serial numbers (S/Ns) of Bombardier-Rotax GmbH type 912 F and 914 F series reciprocating engines. That AD currently requires initial and repetitive visual inspections of the engine crankcase for cracks. This proposed AD would require those same inspections, would add the 912 S series to the affected population, add a test procedure to determine the engine suitability for a special flight permit, and would change applicability from engine S/N to crankcase S/N. This proposed AD results from an increase in the affected crankcase population. We are proposing this AD to prevent oil loss caused by cracks in the engine crankcase, which could lead to in-flight failure of the engine and forced landing.

DATES:

We must receive any comments on this proposed AD by June 7, 2010.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD.

• Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
• Fax: [phone].

Contact BRP-Rotax GmbH & Co. KG, Welser Strasse 32, A-4623 Gunskirchen, Austria, for the service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Richard Woldan, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2010-0342; Directorate Identifier 2002-NE-08-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).

Examining the AD Docket

You may examine the AD docket on the Internet at http://;www.regulations.gov;​; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

On August 7, 2002, the FAA issued AD 2002-16-26, Amendment 39-12865 (67 FR 53296, August 15, 2002). That AD requires initial visual inspection for cracks in the engine crankcase of certain S/N engines, within 50 hours time-in-service (TIS) after the effective date of that AD, and repetitive visual inspections at each 100-hour, annual, or progressive inspection, or within 110 hours TIS since last inspection, whichever occurs first. If any cracks are found, the engine must be replaced. Austro Control GmbH (ACG), which is the airworthiness authority for Austria, notified the FAA that an unsafe condition may exist on certain S/Ns of Bombardier-Rotax GmbH type 912 F and 914 F series reciprocating engines. Austro Control GmbH advises that they have received reports of about 100 engine crankcases found cracked in service worldwide over the past 10 years. To date, no engine failures due to cracks in the crankcase were reported. However, ACG has determined that an engine could fail due to oil loss from a cracked crankcase. This condition, if not corrected, could result in an inflight failure of the engine and forced landing.

Actions Since AD 2002-16-26 Was Issued

Since that AD was issued, we determined that the affected crankcase population has increased, requiring us to expand the applicability of the AD. We also learned that Bombardier-Rotax has introduced a new design crankcase assembly that is not susceptible to the cracking issue. The introduction of the new crankcase design allows us to limit this proposed AD applicability to those crankcases with a S/N of 27811 or below, and to provide an optional terminating action to the repetitive inspections required by AD 2002-16-26.

Relevant Service Information

We have reviewed and approved the technical contents of Rotax Aircraft Engines Mandatory Service Bulletins (MSBs) SB-912-029, Revision 3, dated July 11, 2006, and SB-914-018, Revision 3, dated July 11, 2006, that describe procedures for inspecting the crankcase for cracks. The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has classified these service bulletins as mandatory and issued EASA Airworthiness Directive 2007-0025, dated February 1, 2007 to ensure the airworthiness of these Bombardier-Rotax engines in Europe.

Differences Between the Proposed AD and the Service Information

Rotax Aircraft Engines MSBs specify applicability by engine S/N and replacement crankcase S/N. This proposed AD would specify applicability by crankcase S/N only.

Bilateral Agreement Information

Bombardier-Rotax GmbH type 912 F, 912 S, and 914 F series reciprocating engines are manufactured in Austria, 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, ACG has kept the FAA informed of the situation described above. The FAA has examined the findings of ACG, 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. We are proposing this AD, which would require initial visual inspection for cracks in the engine crankcase of certain S/N crankcases, within 50 hours time-in-service (TIS) after the effective date of this AD, and repetitive visual inspections at each 100-hour, annual, or progressive inspection, or within 110 hours TIS since last inspection, whichever occurs first. If any engine crankcase cracks are found, replace the engine before further flight. The proposed AD would require that you do these actions using the service information described previously.

Costs of Compliance

Based on the service information, we estimate that this proposed AD would affect about 250 products of U.S. registry. We also estimate that it would take about 3 work-hours per inspection and 20 work-hours to replace the crankcase to comply with this proposed AD. The average labor rate is $85 per work-hour. Required parts would cost about $6,500 per crankcase. Based on these figures and an estimate of one crankcase replaced per year, we estimate the annual cost of the proposed AD on U.S. operators to be $68,100. Our cost estimate is exclusive of possible warranty coverage.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106 describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

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 AD:

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 regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

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:

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. The FAA amends § 39.13 by removing Amendment 39-12865 (67 FR 53296, August 15, 2002) and by adding a new airworthiness directive, to read as follows:

Bombardier-Rotax GmbH (formerly Rotax, Motorenfabrik): Docket No. FAA-2010-0342; Directorate Identifier 2002-NE-08-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by June 7, 2010.

Affected ADs

(b) This AD supersedes AD 2002-16-26, Amendment 39-12865.

Applicability

(c) This airworthiness directive (AD) is applicable to Bombardier-Rotax GmbH type 912 F series, 912 S series, and 914 F series reciprocating engines that have a crankcase serial-numbered 27811 or lower, installed. These engines are installed on, but not limited to, Aeromot-Industria Mecanico Metalurgica Itda AMT-300; Aquila Technische Entwiklugen GmbH AQUILA AT01; Diamond Aircraft Industries DA-20A1, Diamond Aircraft Industries GmbH Models HK36TC, HK36TTC, HK36TTC-ECO, and HK36TTS; Iniziative Industriali Italiane S.p.A. Sky Arrow 650 series; SCHEIBE-Flugzeugnau GmbH SF 25C; and Stemme S10-VT aircraft.

Unsafe Condition

(d) This AD results from an increase in the affected engine crankcase population. We are issuing this AD to prevent oil loss caused by cracks in the engine crankcase, which could lead to in-flight failure of the engine 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.

Determining the Crankcase Serial Number (S/N)

(f) Determine if your crankcase is affected by looking at the S/N in the area indicated by XXX, following “Made in Austria,” as shown on Figure 2 of this AD. The marking is on both crankcase halves.

Initial Inspection

(g) Within 50 hours time-in-service (TIS) from the effective date of this AD, perform a visual inspection as follows:

(1) Inspect the engine crankcase (item 1, Figure 1 of this AD) for cracks, especially in the area of cylinder 1 upper side (item 2), between cylinder 1 and 3 upper side (item 3), cylinder 4 lower-right side (item 4) and detailed inspection in the area identified in Figure 2 (item 5) of this AD. Information concerning this inspection can be found in Bombardier-Rotax Mandatory Service Bulletins No. SB-912-029, Revision 3, dated July 11, 2006 and No. SB-914-018, Revision 3, dated July 11, 2006.

(2) Cracks in crankcases of engines with a ROTAX cooling air baffle may not be easily visible, and oil leaks may be an indication of cracks. Visually inspect for oil leaks in areas of (item 2, Figure 1 of this AD) and (item 3).

(3) If you find oil leaks, determine the source by either using a borescope or removing the object blocking the view such as the air baffle or accessory, and perform the inspection.

(4) If the engine crankcase is cracked, replace the engine before further flight.

Repetitive Inspections

(h) Visually inspect the engine crankcase (item 1, Figure 1 of this AD) for cracks at each 100-hour, annual, or progressive inspection, or within 110 hours TIS since last inspection, whichever occurs first, in accordance with paragraphs (g)(1) through (g)(4) of this AD.

Alternative Methods of Compliance

(i) 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

(j) Under 14 CFR part 39.23, we are limiting the special flight permits for this AD by the following conditions if the crankcase is cracked or there is evidence of oil leakage from the crankcase:

(1) Perform a leak check as follows:

(i) Clean the crankcase surface to remove any oil.

(ii) Warm up the engine to a minimum oil temperature of 50 degrees C (120 degrees F). Information about warming up the engine can be found in the applicable line maintenance manual.

(iii) Accelerate the engine to full throttle and stabilize at full throttle speed for a time period of 5 to 10 seconds. Information about performing a full throttle run can be found in the applicable line maintenance manual.

(iv) Shutdown after running the engine at idle only long enough to prevent vapor locks in the cooling system and fuel system.

(v) Inspect the crankcase for evidence of oil leakage. Oil wetting is permitted, but oil leakage of more than one drip in 3 minutes after engine shutdown is not allowed.

(2) Check the crankcase mean pressure to confirm that it is 1.46 pounds-per-square inch gage (psig) (0.1 bar) or higher when checked at takeoff power to ensure proper return of oil from the crankcase to the oil tank. Information about checking crankcase mean pressure is available in the Lubrication System section of the applicable engine installation manual.

(3) A ferry flight is not allowed if oil leakage exceeds one drip in 3 minutes or if crankcase mean pressure is below 1.46 psig.

Optional Terminating Action

(k) Installing a crankcase that has a S/N above 27811 terminates the inspection requirements of paragraphs (g)(1) through (g)(4) and (h) of this AD.

Related Information

(l) Contact Richard Woldan, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone [phone]; fax [phone], for more information about this AD.

(m) EASA airworthiness directive 2007-0025, dated February 1, 2007, also addresses the subject of this AD.

(n) Bombardier-Rotax Mandatory Service Bulletins No. SB-912-029, Revision 3, dated July 11, 2006 and No. SB-914-018, Revision 3, dated July 11, 2006, pertain to the subject of this AD. Contact BRP-Rotax GmbH & Co. KG, Welser Strasse 32, A-4623 Gunskirchen, Austria, or go to rotax-aircraft-engines.com for a copy of this service information.

Issued in Burlington, Massachusetts, on April 1, 2010.

Peter A. White,

Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.