Options for Foxbat Engine.

[APenNameAndThatA]

Hi

 

I am about to purchase an Aeroprakt A22LS Foxbat Kelpie. Comes with the 100 hp Rotax and can be optioned with fuel injection. My question is what engine choice to make and what options to get. My main priority is to reduce pilot workload and have high reliability and safety. Having high performance and/or low fuel consumption is not important. Having to use carb heat is an anathema to me (!#$@ it's 2017 $!@#$). The operating conditions will be low humidity and temps -2 to 45 C, but it could move anywhere in Australia, which includes tropics I suppose in the future. I expect it will be VH registered but will have glass cockpit so should not need a vacuum pump, but I might just be ignorant about that.

 

I expect I will get the model without manual carburetor heat. Fuel injection does not seem to be worth it if it weighs 7kg more, and delivers about 7% increase in fuel economy (just carry 7kg fuel in a jerry can). But if it was a 30% increase in fuel economy then that *might* be different.

 

Do I need a bigger oil radiator? Coolant overflow bottle? What about these thermostats people keep adding?

 

Thanks. And Thanks for reading the long post.

 

P.S. duplicate post from Rotax Owners.

 

 

[SilverWing]

HiI am about to purchase an Aeroprakt A22LS Foxbat Kelpie. Comes with the 100 hp Rotax and can be optioned with fuel injection. My question is what engine choice to make and what options to get. My main priority is to reduce pilot workload and have high reliability and safety. Having high performance and/or low fuel consumption is not important. Having to use carb heat is an anathema to me (!#$@ it's 2017 $!@#$). The operating conditions will be low humidity and temps -2 to 45 C, but it could move anywhere in Australia, which includes tropics I suppose in the future. I expect it will be VH registered but will have glass cockpit so should not need a vacuum pump, but I might just be ignorant about that.

 

I expect I will get the model without manual carburetor heat. Fuel injection does not seem to be worth it if it weighs 7kg more, and delivers about 7% increase in fuel economy (just carry 7kg fuel in a jerry can). But if it was a 30% increase in fuel economy then that *might* be different.

 

Do I need a bigger oil radiator? Coolant overflow bottle? What about these thermostats people keep adding?

 

Thanks. And Thanks for reading the long post.

 

P.S. duplicate post from Rotax Owners.

Hi APenNameAndThatA

 

To help you out - the Aeroprakt factory no longer offers fuel injection as an option. If you don't like the manually operated hot air system for the carburettor engine (which, by the way, allows the engine to develop full power through using cooler air from outside the cowling), some Foxbats have been fitted (admittedly quite a while ago) with UK Rotax dealer-supplied 'hot coolant'-fed rings round the carby throats. I believe these can be fitted with a valve to open or, in summer, close the coolant flow through the rings. Because the rings move the carby inlets towards the firewall, you have to fit pancake filters instead of the standard cone filters. The main potential drawback of the coolant rings is the number of extra hose connections to check before you fly. A second one is that the carbys can get quite hot in OATs above 25 celsius and may under some circumstances vaporise fuel in the inlets.

 

You definitely do not need a bigger oil radiator or larger coolant bottle as the Foxbat engine installation is designed if anything to run a bit cool. We fit oil thermostats as standard on all Foxbat and Vixxen aircraft supplied in Australia.

 

Finally, there is no vacuum pump option for the aircraft. The electrical system is designed for digital 'glass' as needed and can cope with double Dynon SkyViews, transponder, radio, strobes, landing light, UHF radio, mustering siren etc etc.

 

Don't hesitate to give me a call if you need to discuss any of this.

 

 

[rgmwa]

As a point of interest, Vans have just introduced the 912iS in their RV-12 as the standard engine for this plane, although the ULS is also available. A few weeks ago they flew both their 912ULS equipped RV-12 and the iS version side by side from Oregon to Oskosh. The ULS used 60 gallons for the trip and the iS used 45 gallons under as near identical real world conditions as you could probably get.

 

rgmwa

 

 

[SilverWing]

As a point of interest, Vans have just introduced the 912iS in their RV-12 as the standard engine for this plane, although the ULS is also available. A few weeks ago they flew both their 912ULS equipped RV-12 and the iS version side by side from Oregon to Oskosh. The ULS use 60 gallons for the trip and the iS used 45 gallons under as near identical real world conditions as you could probably get.rgmwa

In our experience, the 912iS is definitely more economical over a steady long-range cruise. But not much different to the 912ULS in shorter (eg under 60-90 minutes) flights, and certainly not for circuits and bumps