Roger Lee Posted July 29, 2016 Report Share Posted July 29, 2016 For fun and emergency mental planning. Remember fail to plan, plan to fail. Let's say you're cruising along and a throttle cable breaks and you don't know what happened. Now the engine is shaking. So you instinctively pull back the power and the shake gets worse. Your next move? This will be a two parter when I get a correct response and the second part will fit right in. So then after you do the right thing what are your actions or considerations? If I say more I'll give it away. Link to comment Share on other sites More sharing options...
gbigs Posted July 29, 2016 Report Share Posted July 29, 2016 For fun and emergency mental planning. Remember fail to plan, plan to fail. Let's say you're cruising along and a throttle cable breaks and you don't know what happened. Now the engine is shaking. So you instinctively pull back the power and the shake gets worse. Your next move? This will be a two parter when I get a correct response and the second part will fit right in. So then after you do the right thing what are your actions or considerations? If I say more I'll give it away. This happened to my wife when she was flying with her CFI in their trainer (CTLS with 912ULS). The throttle stuck open after the cable kinked or broke (verified after pulling throttle back and no change ).... They were about two miles away from the airport. He flew in on base (after calling the Tower) and arched in on final. Then he turned the engine off and landed normally knowing the runway was 5,000 feet long (KVGT). Link to comment Share on other sites More sharing options...
Al Downs Posted July 29, 2016 Report Share Posted July 29, 2016 When the cable breaks it goes full throttle. You need to balance out the carbs by adding throttle. When it happened to us we were in the pattern and could simply shut down and glide in to a landing. Link to comment Share on other sites More sharing options...
Ed Cesnalis Posted July 29, 2016 Report Share Posted July 29, 2016 ... Then he turned the engine off and slipped to land. Notice he didn't pull the chute Link to comment Share on other sites More sharing options...
gbigs Posted July 29, 2016 Report Share Posted July 29, 2016 Notice he didn't pull the chute Well, he had more balls than me...(I verified this with my wife, he didn't slip to land, just landed with engine off, see corrected post above). Link to comment Share on other sites More sharing options...
Roger Lee Posted July 29, 2016 Author Report Share Posted July 29, 2016 Hi Al, Perfect answer. "When the cable breaks it goes full throttle. You need to balance out the carbs by adding throttle." Okay now Rotax says only 5 minutes above 5500 rpm. Let's say your WOT rpm is 5700 rpm. Now what do we fly for 5 minutes and land? Do shut down the engine? Link to comment Share on other sites More sharing options...
Al Downs Posted July 29, 2016 Report Share Posted July 29, 2016 You need to head to a landing spot and when you arrive you need to shut down and glide in. I don't think it would be wise or even possible to land at full throttle Link to comment Share on other sites More sharing options...
Anticept Posted July 29, 2016 Report Share Posted July 29, 2016 It's not possible to land at full throttle unless you want to push the prop in (and probably flip over) or land up the side of a steep mountain. Roger: Get as much altitude as possible (which also controls engine RPM) until near a place that you can land safely, then turn off engine and close fuel valve for descent. BUT, shut down the engine only if you have to (you might still need it, so try not to destroy the engine; don't turn one emergency into two), and remember the parachute (if equipped) if the situation requires. "Two things that are useless are altitude above you and runway behind you." Link to comment Share on other sites More sharing options...
Roger Lee Posted July 29, 2016 Author Report Share Posted July 29, 2016 My question is Rotax says 5 minutes above 5500 rpm. What about 5700 rpm for 20-30 minutes to a safe landing site? Who's for getting altitude and shutting down the engine or just flying at 5700 for 20 minutes? If you decided to fly for those 20 minutes what would happen to the engine? Link to comment Share on other sites More sharing options...
Al Downs Posted July 29, 2016 Report Share Posted July 29, 2016 If there is not a place to land nearby it doesn't matter what Rotax says. I think there is a good chance the engine the engine would be fine. In any case I am looking for a place to land as soon as I can and when I am close enough to land I would shut down, slow down and land. This is where plenty of altitude would help so you have time to slow down and set up safe landing. Link to comment Share on other sites More sharing options...
Tom Baker Posted July 29, 2016 Report Share Posted July 29, 2016 With out looking up the specifics, because I'm in Oshkosh. Rotax has instructions for overspeeds, and it is dependent on the amount and duration of the overspeed. Link to comment Share on other sites More sharing options...
Roger Lee Posted July 29, 2016 Author Report Share Posted July 29, 2016 Hi Alo,, You've been peeking In fact running at that 5700 rpm for 20-30 minutes won't hurt the engine. So fly to a safe place like a runway set yourself up and shut down the engine to land. Just remember no go arounds. This has been tested and there is plenty a safety factor there. Link to comment Share on other sites More sharing options...
Roger Lee Posted July 29, 2016 Author Report Share Posted July 29, 2016 I'm not 100% sure they would categorize this as an over speed. Maybe. Here are the test parameters from Rotax no matter what 912 they use (UL or certified) After the endurance run the engine is torn down all parameters must be within serviceable limits.Part 1 A 30-hour run consisting of alternate 5 minute periods at Take-off Power and speedand Maximum Best Economy Cruising Power or Maximum Recommended Cruising Power conditions.Part 2 A 20-hour run consisting of alternate periods of 1.5 hours at Maximum ContinuousPower and speed and 0.5 hour at 75% Maximum Continuous Power and 91% Maximum Continuous speed.Part 3 A 20-hour run consisting of alternate periods of 1.5 hours at Maximum ContinuousPower and speed and 0.5 hour at 70% Maximum Continuous Power and 89% Maximum Continuous speed.Part 4 A 20-hour run consisting of alternate periods of 1.5 hours at Maximum ContinuousPower and speed and 0.5 hour at 65% Maximum Continuous Power and 87% Maximum Continuous speed.Part 5 A 20-hour run consisting of alternate periods of 1.5 hours at Maximum ContinuousPower and speed and 0.5 hour at 60% Maximum Continuous Power and 84.5% Maximum Continuous speed.Part 6 A 20-hour run consisting of alternate periods of 1.5 hours at Maximum ContinuousPower and speed and 0.5 hour at 50% Maximum Continuous Power and 79.5% Maximum Continuous speed.Part 7 A 20-hour run consisting of alternate 2.5 hour periods at Maximum ContinuousPower and speed and Maximum Best Economy Cruising Power or Maximum Recommended Cruising Power condition Bottom line it will get you to where yo need to go. Link to comment Share on other sites More sharing options...
Al Downs Posted July 29, 2016 Report Share Posted July 29, 2016 Until something like the cable happens to you or someone you know, it isn't something that crosses your mind. Ours broke half way from the end of the sheilding and the point where it connects. About a 2 inch area where nothing can touch or damage it. Never could figure out how or why it broke but was really glad it was in the pattern. When it happens it feels like you are in a paint shaker and it confuses the hell out of you. More throttle doesn't seem right but once you understand what is going on, it is the correct action. Every pilot flying the plane needs to be educated on this because to does happen. Link to comment Share on other sites More sharing options...
Anticept Posted July 29, 2016 Report Share Posted July 29, 2016 I'm not 100% sure they would categorize this as an over speed. Maybe. Here are the test parameters from Rotax no matter what 912 they use (UL or certified) You made me pop open the MM. Line maintenance manual doesn't even have an overspeed or time entry for anything less than 5800rpm. Chapter 5-50-00 paragraph 3.4 Link to comment Share on other sites More sharing options...
Runtoeat Posted July 29, 2016 Report Share Posted July 29, 2016 FWIW, I would first add throttle and climb (aviate), then I would look for "nearest" on my GPS and set a course (navigate), then I would call on 121.5 and declare an emergency and press my beacon "on" (communicate). Once at a safe altitude and over the "nearest", shut down and circle for a landing. All the while keeping the 'chute deployment as "plan B" backup. This is a really good "what if" safety exercise. The thought of a broken throttle causing the carbs to function unevenly didn't occur to me. Thanks Roger. Link to comment Share on other sites More sharing options...
ausctls Posted July 29, 2016 Report Share Posted July 29, 2016 Roger Lee, on 29 Jul 2016 - 11:35 AM, said: My question is Rotax says 5 minutes above 5500 rpm. What about 5700 rpm for 20-30 minutes to a safe landing site? Who's for getting altitude and shutting down the engine or just flying at 5700 for 20 minutes? If you decided to fly for those 20 minutes what would happen to the engine? I would probably just increase the prop pitch to prevent over revving. Then turn it off when an ALA was in sight. Link to comment Share on other sites More sharing options...
Al Downs Posted July 29, 2016 Report Share Posted July 29, 2016 How are you going to increase the prop pitch? Link to comment Share on other sites More sharing options...
ausctls Posted July 29, 2016 Report Share Posted July 29, 2016 with a variable prop.. Link to comment Share on other sites More sharing options...
Al Downs Posted July 29, 2016 Report Share Posted July 29, 2016 CTLS's do not have a variable prop that I am aware of Link to comment Share on other sites More sharing options...
ausctls Posted July 29, 2016 Report Share Posted July 29, 2016 are you sure? CTLS's do not have a variable prop that I am aware of Link to comment Share on other sites More sharing options...
Al Downs Posted July 29, 2016 Report Share Posted July 29, 2016 I thought it wasn't allowed on Light Sports Link to comment Share on other sites More sharing options...
ausctls Posted July 29, 2016 Report Share Posted July 29, 2016 I do have a variable prop.. Link to comment Share on other sites More sharing options...
FastEddieB Posted July 29, 2016 Report Share Posted July 29, 2016 I thought it wasn't allowed on Light Sports Different countries, different rules. Link to comment Share on other sites More sharing options...
Al Downs Posted July 29, 2016 Report Share Posted July 29, 2016 Didn't realize he is from another country Link to comment Share on other sites More sharing options...
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