Assuming this is about RAAus aircraft, (since RAAus was mentioned) why not read the first two paras in section 12.8 of the RAAus Tech Manual instead of all this guesswork and mis-information?
I'm not in RAAus, and I found it in about one minute of looking online. It's been there, unchanged, for the last three years. When it doubt about something, just check the facts out for yourself, it won't take long.
Never blindly rely on what "someone" told you - too many people do this as their first and only option, why?? Check the facts, in many cases you might be pleasantly surprised.
Questions/topics of similar nature would best be posed not as "what is the answer I seek?" but "where do I find the answer I seek?"
And there I end the lesson, not by giving you the answer you seek (after all, I'm just another "someone"), but guiding you to where it is where you can see it for yourself, and no guesswork is required.
Good hunting.