ARBN 070 931 645

An Inspection of Rotax 912 and 914 Propeller Gearboxes has been specified in the two MANDATORY Rotax Service Bulletins: 912-027 and 914-010. Copies of these are on the website (from the airworthiness page) and should be available from distributors. Failing this, they can be obtained from the AUF Office.

Apparently the problem should mainly be evident on relatively new engines because it is associated with the introduction of wider gears.

The Bulletins require checking of backlash of certain serial numbered Rotax 912A, 912UL 914F and 914UL Propeller Gearboxes to determine whether incorrect components are installed and to require their replacement as necessary. They are classified as Mandatory by Rotax and have been mandated by the CASA in AD/Rotax/9.

Note that in reviewing the UL service bulletins, the Office has noted that they are of one page only whereas the A and F Bulletins are of 8 pages. This is because the UL bulletin does not contain the maintenance actions. It only determines applicability and then refers the UL owner requiring the action back to the A and F bulletin. (Both Bulletins are on the web site)

The AUF will not be raising a corresponding Airworthiness Notice, but members are reminded that recent CASA Legislation places the onus of accomplishing maintenance on aircraft owners. The same applies with the AUF.

This will be published in the AUF magazine.

R Hewitt-Cook

Technical Manager