Rotax throttle settings

[bones]

Ok i was just reading through the last GN and came across this little bit of info.Also noted was the fact that the rotax 912S engine had not had the throttle system modified such that in the event of a throttle cable failure, the caruretor butterfly defaults to closed. Engines are delievered from the factory such that if the throttle cable breaks, the engine runs to full power. This is not recomended by ASRA. This is not recomended by ASRANow this is very interesting reading for me, because all my machines are set up this exact way, my thinking on the matter is if the cable breaks the motor will go full noise, at least giving you a chance to find somewhere to shut the motor off, and hopefully land without damage.The other option of the motor going to idle, to me is not as safe an idea, as i know of 3 machines seriously damaged when the cables broke, and the motor went to idle, not giving the pilots a snow flakes chance in hell, apart from finding out exactly where they were going to crash.I have even seen Soobie motors, set up with springs to make the throttle go full power in this case.So what does every one else think on this subject, is it better to have full power or idle, in this situation??Even better what is the thoughts of the ASRA board(i presume) thinking the best option is to go to idle?

[aussie_paul]

Ok i was just reading through the last GN and came across this little bit of info.Also noted was the fact that the rotax 912S engine had not had the throttle system modified such that in the event of a throttle cable failure, the caruretor butterfly defaults to closed. Engines are delievered from the factory such that if the throttle cable breaks, the engine runs to full power. This is not recomended by ASRA. This is not recomended by ASRANow this is very interesting reading for me, because all my machines are set up this exact way, my thinking on the matter is if the cable breaks the motor will go full noise, at least giving you a chance to find somewhere to shut the motor off, and hopefully land without damage.The other option of the motor going to idle, to me is not as safe an idea, as i know of 3 machines seriously damaged when the cables broke, and the motor went to idle, not giving the pilots a snow flakes chance in hell, apart from finding out exactly where they were going to crash.I have even seen Soobie motors, set up with springs to make the throttle go full power in this case.So what does every one else think on this subject, is it better to have full power or idle, in this situation??Even better what is the thoughts of the ASRA board(i presume) thinking the best option is to go to idle?Bones, this rule was very important when gyros were less

[birdy]

[ this is go"n t hurt]I agree with PB.

[bones]

PB i didnt think of that it does make sense though.Birdy, i bet it hurt

[Brian]

I havent flown a single seat 912 machine but knowing what power the 2.2 suby has at full noise, I imagine that a 912 would be similiar. Those of us with enough expereince probably isnt going to have to many dramas switching off an out of control engine but I have been told that a 912 at WOT sometimes ...sometimes will not respond to the magnetos being switched off. Now that came from A bloke at Bert Floods so I"m assuming he knows his stuff. Take an inexpereinced pilot with a gyro at full noise not resonding to throttle inputs, I could visualize an accident happening or a wils panic happening.Starting a 912 gyro at full noise isnt going to be helpful either

[asra]

Waddles and I spoke at length about this issue.It all arises from the accident mentioned above and as its under investigation from those a lot higher up the food chain than us,cant be discussed here,in detail anyway.On one hand you have the argument that this is the way the engine comes from the factory,i.e if the cable breaks it goes to full noise.On the other as PB said this could be a recipe for disaster in the wrong hands with the wrong gyro.ASRA cant make either setup mandatory as it could be argued that both systems COULD be dangerous.Personally If I was flying a CLT gyro or one of the new European designs I would opt for "full noise please"

[birdy]

cant be discussed here,in detail anyway.???????Duno wot your talkn bout, but im gessn sumone setup a new 912, not known the throttle is full open at rest, started it the first time and sumthn hit the fan?For starters, a 912 wont start with the throttle wide open, and second, if i payed criminal amounts of coin for an engine, id read the instilation manual BEFORE i started.

[dineshkkk]

As I hear to you all, arriving at a conclusion in the form of a digital answer (full power or idle) doesn’t appeal to me.

[bones]

Dineshkkk, that would be great in a perfect world, actually to never have anything go wrong on an aircraft would be best.How ever the usual thing is to have the carb throttles go either full or idle, otherwise, how do you get them both(rotax situation) to hold where they are?I guess you could have some type of friction set up somewhere and have a type of connection between both carbs, maybe a fixed rod thingy with rod end type swivels for each side,

[dineshkkk]

Dineshkkk, that would be great in a perfect world, actually to never have anything go wrong on an aircraft would be best.How ever the usual thing is to have the carb throttles go either full or idle, otherwise, how do you get them both(rotax situation) to hold where they are?I guess you could have some type of friction set up somewhere and have a type of connection between both carbs, maybe a fixed rod thingy with rod end type swivels for each side,

[hatrack]

Never heard of too much power in a gyro. If it"s going full noise, nose up and gain height. Gives you heaps of time to assess the situation and decide what to do. After the latest CLT tests, isn"t a no-brainer? Am I missing something?

[dineshkkk]

Never heard of too much power in a gyro. If it"s going full noise, nose up and gain height. Gives you heaps of time to assess the situation and decide what to do. After the latest CLT tests, isn"t a no-brainer? Am I missing something?

[asra]

cant be discussed here,in detail anyway.???????Duno wot your talkn bout, but im gessn sumone setup a new 912, not known the throttle is full open at rest, started it the first time and sumthn hit the fan?For starters, a 912 wont start with the throttle wide open, and second, if i payed criminal amounts of coin for an engine, id read the instilation manual BEFORE i started.Not doubting you for one minute but if this is fact we need to know about it ASAP,What about with the choke full on as well?Can those with 912"s out there do some tests for me and report back?

[birdy]

The choke is neutralised soon"n the throttle is cracked.Iv never gotn even a cof outa a 912 if the throttle is open more n just cracked [ bout 2200rpm setn], with or without choke, hot or cold.Not sayn it CANT start, just sayn iv never had it start above fast idle.I would do sum tests, but itll have t wate a few days. We got a fire bout 150km upwind of us, and its not lookn like a real happy fire.

[MilesW]

Can those with 912"s out there do some tests for me and report back?Did a test this arvo for you. 912ULS (100HP)Wide open throttle. It absolutely, most definitely starts!!!!! Almost instant acceleration . Pretty startling sitting in the machine. Would NOT want to be standing anywhere near it.The carby"s are set up so that with any throttle on at all you cannot engage the choke. But, with the choke already on you can advance the throttle to full noise. Did not think it would be too clever to try to start it in this state, so can"t help you with that particular scenario.For my two bob...Failing to full noise may not be the safest option on the ground, but I would not have it any other way for a machine doing station flying.Miles