Rotax

[GAVM]

Does the rotax have single point failure electronic ignition?

[avidflyer]

What Rotax are you asking about? Early 2 strokes had points ignition. Later 2 strokes went to CDI ignition, 503 and 582 were dual ignition, and 912 has dual electronic ignition

[GAVM]

The engine is an Edgeperformance EP915Eci

[Eric Page]

I'm not aware of any Kitfoxes flying with the EP915ECi. Most Kitfox builders who use an Edge engine buy the EP912STi.

The Edge Performance website doesn't appear to offer engine manual downloads, but you can ask them about the EP915ECi via their contact form (https://www.edgeperformance.no/contact).

[GAVM]

I can confirm that I have fitted the EP915Eci with a constant speed Airmaster propeller to my Kitfox 5 Safari Speedster and it performs extremely well now - maybe too well! Could somebody tell how I could fit an auxiliary power system that would give me backup power for about 30 mins in case of an electrical failure.

[Shadowrider]

Your battery should be able to do that? Maybe explain more what you are thinking?

[GAVM]

If my charging system failed and my battery started to drain is there something that a could switch to to give me 30 minutes to find somewhere to land! Once the battery is flat then the engine stops being fuel injection.

[Shadowrider]

Couple options. I opted for a separate charging system. Edge sells aftermarket alternator that I use. The stock rotax system with the rotax voltage regulator stays as my backup charging system. I run everything off my edge 35 amp alternator that has its own voltage regulator. Usually charging system goes down because of the voltage regulator failing. If that happens then I run my buss off my rotax stock alternator system. I have will have to cut back what I am running, like lights or heater. I opted for a single buss so everything can be powered if I want. I have two breaker switches that select what charging system I am running off. I can run one or the other or both. I prefer to run off one and have the other on standby.

Another option is install a backup battery that can be used to power your buss and extend your flight time off battery power? But yes you are correct you are running a electric engine now. Make sure to setup good alarms that let you know if your charging system has failed so your now running off battery power and not knowing it. With that being said I know of someone who took off without his charging system working and flew for over an hour off battery power. He has two g3xs, two radios, autopilot, basically all the bells and whistles and he got an hour before his engine died. I have my g3x to alert me if my battery volts drop below 13.2 volts, the resting volts of the earthx battery. Below 13 volts and another red alarm will alert me if I missed the yellow warning. I would argue electricity is more important that fuel on these engines!

[napierm]

If my charging system failed and my battery started to drain is there something that a could switch to to give me 30 minutes to find somewhere to land! Once the battery is flat then the engine stops being fuel injection.
If a few minutes off the battery is not enough I would think about a 2nd alternator. There is the front mounted pulley kit from Rotax. If you have room there is the standby alternator that can be mounted on the vacuum drive pad behind the gearbox. Also there are 2nd alternators made to mount behind the magneto/flywheel.

[GAVM]

Thank you for your advice it has been most useful

[skyguy04]

Wo, this is the first I’m learning about this potential issue with the Edge Fuel Injected engines. The Rotax 912 engines have THREE power sources built right into the engine. 3 engine driven stators. Adding an alternator would be a 4th! In the carbureted models, there is 1 stator per electronic ignition and 1 to drive the main bus for cabin power. If the voltage regulator dies, I do not believe it effects the engine at all. Someone please correct me if I’m wrong.

Does the Edge EFI rely on the voltage regulator to be working? Are all the stators still in use? Seems like a bad idea to have a single point of failure in an aircraft engine.


Sent from my iPhone using Tapatalk

[napierm]

Yes, it's hard to defeat the redundant ignition on the Rotax. As long as the fuel and oil keep flowing that fan will keep spinning. Even loss of coolant won't force a landing but can cook the heads.

But the 912iS can have similar issues to the Edge. I think it does have built-in dual power sources for electrical but I saw a you-tube video of a *nice* LSA with a 912iS that had to land in a field due to an electrical problem so the system design has to be right.

https://www.youtube.com/watch?v=XTN68B4vry8

[Shadowrider]

Wo, this is the first I’m learning about this potential issue with the Edge Fuel Injected engines. The Rotax 912 engines have THREE power sources built right into the engine…

The edge efi does not rely on the voltage regulator to run and I am not sure where you got that? I can think of many single points of failure on even the most advanced “single” engine. Single fuel source, single oil pump, single crank, single cam, single master solenoid, ect. At the end of the day still a single engine that a single failure can take it out. Point is on a efi your electrical needs to be well thought out and have multiple power sources IMO.

[VictorV]

The stock 915is has 2 generators. One for the engine and the other for the "rest of the plane". If one fails, the engine automatically switches over to the still-good generator
and disconnects from the "rest of the plane". If that generator fails you then can run from your main battery. The 915/912 engines need 8 amps to run everything including
fuel pumps. So you'd use 4ah for 30 minutes of flight. The ETX-900 battery is 16ah so you could still run for a few hours on the main battery alone depending on how much load
you can shed. The chances of 2 generators and a battery all failing at once is incredibly unlikely to happen. You probably have a higher chance of being taken out by a meteor.

My question is do you really need that much redundancy? If you want to fly even longer you can use an ETX-1200 battery
with a 24ah capacity which only weighs another couple of pounds. Cheaper and lighter than a backup alternator. With that
you could stay in the air for maybe 4 hours.

If you need more than 30 minutes to find a place to land you're probably flying somewhere you shouldn't be :)

Victor

[GuppyWN]

I can confirm that I have fitted the EP915Eci with a constant speed Airmaster propeller to my Kitfox 5 Safari Speedster and it performs extremely well now - maybe too well! Could somebody tell how I could fit an auxiliary power system that would give me backup power for about 30 mins in case of an electrical failure.

Talk to Thomas. He sells a second alternator.