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0G In a CT?


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Hi Brendan,

I would caution against any prolonged negative G maneuvers for a couple reasons.


1. the rotax is not certified for prolonged negative g's or aerobatics

2. The engine may quit from fuel starvation

3. you could introduce air into the oil system from floating the oil to the top of the sump, which could be harmful to the engine

4. The CT load limit factor is much less negative than positive. -2 vs 4


The manual prohibits it if the flaps are deployed past 0.


Just my 2 cents.

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Hello Brendan,

- related to plane - indeed, the published safety load limits are +4/-2g. but it's a little difficult to create -2g without some really advanced aerobatic figures.

- related to ROTAX - theoretically it's clear: max -0.5g for max 5 sec.

I think it is not a problem to keep the plane for a few seconds at 0g, but as coopercity said, only for very limited time. However, it could be useful to keep an airfield in sight when you do this :)





excerpt from OM Rotax 912.

post-34-058227900 1284457033_thumb.jpg

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Ok, now I see. You mean Zero G's.

These guys answered it.

Momentary as you do a maneuver, but any thing past a couple of seconds is to long for the engine and the airframe. This is in print for Rotax and FD. If it is only stall practice that isn't a big deal. I practice stalls all the time. Their fun and very straight forward in the CT. You can do them where they are gentle and kind of just mush or a much harder nose up and let the nose break over. Other than stall practice I personally don't see a reason to get into zero or negative G's.

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My experience when flying near 0G is, that fuel is likely to come out of the carburetors. I tried it a few times and at anytime a very strong smell of fuel entered the cockpit.


I dont like to catch a fire during flying and therefore I avoid maneuvres which result in low G's.


Kind regards



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  • 2 months later...

Rotax allows -0.5G for up to 5 seconds. I doubt they would permit it if the engine tended to catch fire occasionally. I fly 0G pushovers quite a bit. It's a very gentle maneuver but surprisingly unsettling to people who have never done it. Much more so than an accelerated stall or 60deg turns.

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  • 7 months later...


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