IMC and Rotax engines

Right.  I'm not talking about FIKI - just IMC.  Having FIKI is a pretty rare on experimental - at least I'm not aware of any that are out there.  I've got a heated pitot on my SlingTsi - and most of them are built that way, but that's back to the config of the aircraft and equipment on the aircraft not specifically related to the engine.  The problem seems to be in a misunderstanding by a number of people that point at the Rotax engines and go "they aren't legal to fly into IMC"... so it's their belief they aren't legal to fly into IMC but it appears to be based on their assumption and not any legal guidance.  

I think the US TCDS mentioned earlier is closer to the truth of the matter... 

Basically the folks I'm having this conversation with I'm asking them the same question - what sort of regulatory or legal guidance are they relying upon to form their opinion.

Hi Brian

I think that that rumor starts with the F37 standards for light sport aircraft.  There is no instrument or call out for how an aircraft can be qualified for what we call full iFR, this would be flying in clouds and iMC.  Within the standards an LSA aircraft can be fitted by an OEM for IFR flight but must call out no flight into IMC since there is no call out on how to qualify the aircraft for those conditions.  The pitot tube is a very good example of a basic part of that, heated it is fine for iMC but unheated I don't believe it is.  

If you are flying experimental then you can do whatever you want but using the guidance from the FARs would be wise.  As far as the engine is concerned this is an airframe/builder issue.  Rotax does note in some publications that they would like OEMs to use the certified versions of the engine for any IFR.  Their idea is that it would then be maintained by persons familiar with the regulatory issues with such issues as qualified equipment and best practice.  Just my opinion. 

Cheers

I don’t think it’s rare to have a heated pitot now days. My RANS S21 with Rotax 916 is IFR into IMC legally equipped and capable. Generally I would not fly a plane without icing protection in extended hard IMC, but have used an IFR clearance to poke through a cloud layer many times.  Nothing in the regs say the plane has to be certified, just meet the requirements and inspections. I have a lot of redundancy in avionics and backup batteries. If I planned to fly more into IMC I’d install an external alternator for further redundancy (especially considering the recent stator issues). 

Hi Jason

So I assume you are flying as an AB aircraft and therefore you have no legal requirement to have anything called out by the F37 for Light Sport airplanes.  The question was where did someone get the idea Rotax prohibited this, they did not.  The only prohibition is found in the F37 airplane standards where flight from IFR into iMC is prohibited.  

Cheers

Jason Knight wrote:

I don’t think it’s rare to have a heated pitot now days. My RANS S21 with Rotax 916 is IFR into IMC legally equipped and capable. Generally I would not fly a plane without icing protection in extended hard IMC, but have used an IFR clearance to poke through a cloud layer many times.  Nothing in the regs say the plane has to be certified, just meet the requirements and inspections. I have a lot of redundancy in avionics and backup batteries. If I planned to fly more into IMC I’d install an external alternator for further redundancy (especially considering the recent stator issues). 

Jason please check the specs on what it takes to have a heated pitot.  Most have 2 power settings, low power is 10 amp and high is 20 amp.  Without adding electrical generation supply it seriously puts your generator into max.  Drawing more than 80% of your power generation to run a heated tube could lead to some serious problems down the line.  As an experimental for sure you can fly iFR with the correct equipment but over taxing the electrical generator will defeat all of your redundant systems.  

If you have found a heated pitot that draws less than 10 amps then I would welcome some information on that. 

Cheers