The Engine Arrives
Rotax 912ULS
After all the planning, the engine is in the shop. Although I chose the engine model before the plane, it isn't needed until late in the building process. Seems small and light; hard to imagine it will produce 100hp. The project seems more real now that the engine has been purchased. More spent here than on the rest of the kit, so far.
This engine has many recent improvements including:
A slipper-clutch between the gearbox and propeller
A larger starter motor
Carb bodies made of a hard alloy less likely to be damaged by high vibration.
While the design is certainly mature, Rotax continues to improve the engine, such as the the redesigned clutch which allows the prop and engine to slip against each other if the engine is idling roughly, or the prop contacts the ground, thereby preventing gearbox or engine damage. The larger starter motor gives quicker starts. This reduces the time that the engine is runing so slowly that the virbation loads up the gearbox/prop. The carb alloy improvement was developed because some users didn't keep the carbs correctly adjusted. This causes the engine to vibrate excessively at idle and slowly damage the carbs.
A Second Alternator
I decided on this B&C alternator to provide backup to the the built-in alternator at a weight penalty of only 5Lbs. Both alternators will produce around 18 amps each. This airplane will fly without a functioning electrical system. In the my local airspace, a failed radio and transponder could allow me a good look at an F-14 scrambled by homeland security. Also, I value dispatch reliability; if I am far from home and my one alternator was to fail, the correct procedure would be to land at a local airport and repair. Parts can take days to a week to obtain. My general plan will be to travel on the weekends, back at work Monday morning. My employer wouldn't appreciate me skipping a week of work, and I don't want the expense of getting home without my plane.
