I’m an RV newbie but experienced E-AB Velocity builder -- custom Turbocharged TNIO-550N Velocity XL/RG/XC with 1500 hrs from Mt Denali to the British Virgin Islands.
I’m interested in building an E-AB RV-12 with a Rotax 915iS engine and configured for long distance, high altitude cross country use -- like my Velocity but about half the TAS!
Some of the most important modifications for the RV-12 would be the Rotax 915iS turbo engine, the addition of oxygen, and a larger fuel tank.
My experience is that cruising in the low flight levels not only provides the most efficient TAS conditions (depending on winds aloft), but also the advantage of being above most weather, and the important flight safety consideration of having 2x to 3x the ‘energy’ and glide range that provides many more safe emergency landing alternatives, options and troubleshooting time.
My primary questions are:
1) would there be insurmountable physical challenges installing a 915iS instead of the normal 912iS engine (like the firewall size or the stepped firewall configuration, etc.) – I understand I will have to completely redesign and fab my own engine cowling,
2) would anyone expect any particular issues with high speed flutter and/or envelope extension during a Phase I flight test issues aimed at (among other things) extending the Vne up to something more like 150 to 160 KTAS -- I understand also of course that major weight and balance adjustments will need to be made to compensate for the greater engine and prop weight, additional fuel, etc.?
Does anyone have any experience with the 915iS on the RV-12, and/or other suggestions or thoughts with regard to the issues I might encounter in the build as well as in the high altitude (e.g., FL180), long distance (800+ NM) cross country flight use case?
I'm just starting to consider the possibilities seriously and would appreciate any experienced RV user inputs or suggestions.
Thanks,
Bob Jackson
N2XF
I’m interested in building an E-AB RV-12 with a Rotax 915iS engine and configured for long distance, high altitude cross country use -- like my Velocity but about half the TAS!
Some of the most important modifications for the RV-12 would be the Rotax 915iS turbo engine, the addition of oxygen, and a larger fuel tank.
My experience is that cruising in the low flight levels not only provides the most efficient TAS conditions (depending on winds aloft), but also the advantage of being above most weather, and the important flight safety consideration of having 2x to 3x the ‘energy’ and glide range that provides many more safe emergency landing alternatives, options and troubleshooting time.
My primary questions are:
1) would there be insurmountable physical challenges installing a 915iS instead of the normal 912iS engine (like the firewall size or the stepped firewall configuration, etc.) – I understand I will have to completely redesign and fab my own engine cowling,
2) would anyone expect any particular issues with high speed flutter and/or envelope extension during a Phase I flight test issues aimed at (among other things) extending the Vne up to something more like 150 to 160 KTAS -- I understand also of course that major weight and balance adjustments will need to be made to compensate for the greater engine and prop weight, additional fuel, etc.?
Does anyone have any experience with the 915iS on the RV-12, and/or other suggestions or thoughts with regard to the issues I might encounter in the build as well as in the high altitude (e.g., FL180), long distance (800+ NM) cross country flight use case?
I'm just starting to consider the possibilities seriously and would appreciate any experienced RV user inputs or suggestions.
Thanks,
Bob Jackson
N2XF