Rotax New Manual

For those of you who own aircraft with 912 Conair have issued this updated information.

NOTE : The only new Cranckcase at this time within the Old Sarum aircraft that i'm sure about is G SARM and G WSSX

Rotax have recently sent out a Service Bulletin regarding upgrade to 2000 t.b.o. for 912 series engines.  As part of this they have also issued a new Line Maintenance Manual.  We have spent some time studying this information, and below is a summary of how this may affect owners, and a summary of changes to the Line Maintenance Manual.

TBO increase to 2000Hrs on Rotax 912UL/A/F (80HP) & 912S/ULS ULSFR (100HP).

For engines purchased from around early 2007 that have a newer crankcase design, the upgrade is fairly simple.  All that is required is new oil pressure plug screw, oil pressure relief spring a new Line Maintenance Manual 899735 issue 2 revision 0 & a new Heavy Maintenance Manual 899603 Issue 1 revision 3 All relevant SB’s & SI’s must have been have been complied with as well.  Your aircraft manufacturer may have additional requirements or restrictions.

Earlier engines will need substantially more work and probably will have to have the crankcase replaced to benefit from the TBO increase.  Please check all relevant Service Bulletins for the correct information.

Summary of the 912 Line Maintenance Manual Update for engine types 912UL/A/F, 912UL/ULS/ULSFR

We have identified the following relevant amendments in the recently issued 912 line maintenance manual 899735 issue 2 revision 0.  If you see anything we have missed please let us know so that we can circulate the information.

.     Operating hours have been defined clearly as total engine run time irrespective of load – i.e. Hobbs hours.

.     912S/912ULS/ULSFR spark plug change intervals increased to every 200Hrs (Previously 100Hrs) but removed and checked @100Hrs. With Avgas usage it is the same as before, more than 30% and plugs replaced @ 50% ie 100Hrs

.       Spark plug gaps reduced to 0.6-0.7mm (previously 0.7-0.8mm).

.       The lower end of the friction torque has been increased slightly to 30Nm.

.       The oil filter inspection has an additional check of running a magnet over the surface of the filter element.

.      Pressure for the differential (leak down compression) test carried out has been altered to 80-87PSI.  The normal compression test can only be used for fault diagnosis now.

.      Annual or every 200hrs inspection of the carburetor bowls (previously biennial or 200hrs).

.       Gearbox service intervals have been altered.  All gearboxes without slipper clutches have had their service intervals increased to 600Hrs            (previously 400Hrs).  912S/912ULS/ULSFR gearbox overhaul increased to 1000Hrs (previously 800Hrs).

Line Maintenance Manual 912UL/912ULS/ULSFR Changes to Special Checks:

.      Overspeed inspections have been altered.  The inspection for an overspeed up to 6200rpm (more than 1 min) now has additional inspections to check the crankshaft for out of round & a phasing check.

.       The repair work for an engine that has exceeded 6200rpm now includes the replacement of the crankshaft.

.      Special checks for low oil pressure now include the requirement to replace the crankshaft under certain conditions.