Bombardier Rotax 912 and 914 "Ul" series engines - Civil Aviation Safety Alerts (CASA) No. 2013-02

Owners and maintainers of aeroplanes equipped with Rotax 912 or 914 "UL" series engines.

Issuing Office: National Aircraft Certification Branch
Document No. : CASA -2013-02
File Classification No. : Z 5000-35
Issue No. : 01
RDIMS No. : 8297638
Effective Date: 2013-06-04


The purpose of this Civil Aviation Safety Alert is to advise owners of aeroplanes, that may have a Bombardier Rotax 912 or 914 "UL" series engine installed, of the following:

The Rotax series "UL" identifies the engine as a non-type certified model. However, these engines are subject to the same non-compliance of installed cylinder head assemblies as identified in European Aviation Safety Agency (EASA) Airworthiness Directive (AD) 2013-0117-E, applicable to the Rotax 912 and 914 type certified engines.


EASA issued AD 2013-0117-E to identify an unsafe condition that if not detected and corrected, could lead to an oil leak in the intake channel in the area of the valve guide. The affected non-conforming cylinder heads may have small machined through holes, which can increase the oil consumption and can lead to oil starvation, possibly resulting in engine stoppage or in-flight engine shutdown and forced landing, with consequent risk of damage to the aeroplane and injury to occupants.

These engines are manufactured in Austria and EASA is the Civil Aviation Authority (CAA) for the country of design responsibility. EASA AD 2013‑0117-E is applicable to Rotax 912 or 914 (excludes the "UL" series) installed on any Canadian registered type certified aeroplane. The installation of these engines was either done by the respective aeroplane manufacturer or through modification of the aeroplane by Supplemental Type Certificate.

It has been determined that the safety concern identified by EASA AD 2013-0117-E also exists in the Rotax 912 and 914 "UL" series engines installed on Canadian registered non-type certified aeroplanes. These aeroplanes would mostly be in the Amateur-Built category and are not subject to ADs.

The engine manufacturer has issued Alert Service Bulletins (ASB) for both the type certified and non‑type certified engines. These bulletins can be retrieved at the following manufacturer's web site without need to register or cost:

Also, the following Rotax web site has an excellent video that explains and describes the safety issue:

Recommended action:

Transport Canada recommends that owners of the Rotax 912 and 914 "UL" series engines installed in Canadian registered aeroplanes comply with the ASB 912-062UL or ASB 914-044UL, as applicable, issued by the engine manufacture.


Defects, malfunctions and failures occurring on aeronautical products are to be reported to Transport Canada, Continuing Airworthiness in accordance with CAR 521 mandatory Service Difficulty Reporting requirements.

Contact office:

For more information contact a Transport Canada Centre; or Marcel Gauthier, Continuing Airworthiness, Ottawa, at 613-952-4357, facsimile 613-996-9178, or e-mail

For the electronic version of this document, please consult the following Web address

For the Director, National Aircraft Certification


Derek Ferguson
Chief, Continuing Airworthiness

The Transport Canada Civil Aviation Safety Alert ( CASA ) is used to convey important safety information and contains recommended action items. The CASA strives to assist the aviation industry's efforts to provide a service with the highest possible degree of safety. The information contained herein is often critical and must be conveyed to the appropriate office in a timely manner. The CASA may be changed or amended should new information become available.