P160SX Flame-out
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P160SX Flame-out
I have a P 160SX with less than 1 hour runtime. Had a flight for about 4 minutes (was the second flight in colder weather 19 degrees overcast weather) at low speeds, only opened up to do some manoeuvres. On a level pass at low speed I opened throttle to which it responded with splatter (almost if the turbine was flooding). I throttled back again, waited and then opened up again slow with the same problem of splatter and then flame out. The data displayed “low RPM”. After testing on the ground we also found the turbine dies if you cut the throttle stik faster. Then display again "low rpm".
I changed the respond settings all to “normal” because we are at an altitude of 4000 feet. So a normal response is acceptable. Still cuts when the throttle is closed giving “low idle RPM”.
When further checking in the limits menu I saw the ”minimum RPM” was set at 32K rpm and the “low idle RPM” is also set at 32K RPM. The low idle RPM only adjusts upward if you adjust the minimum RPM upward. I cannot make the idle RPM higher separately in the limits menu.
What should the settings be and how do I adjust it.
I changed the respond settings all to “normal” because we are at an altitude of 4000 feet. So a normal response is acceptable. Still cuts when the throttle is closed giving “low idle RPM”.
When further checking in the limits menu I saw the ”minimum RPM” was set at 32K rpm and the “low idle RPM” is also set at 32K RPM. The low idle RPM only adjusts upward if you adjust the minimum RPM upward. I cannot make the idle RPM higher separately in the limits menu.
What should the settings be and how do I adjust it.
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Minimum RPM is the normal idle setting. If you are getting flameouts on rapid returns to low throttle, then you might want to increase this setting to 34-35k rpm. At your altitude the change in residual thrust will probably not be a problem. You can also change the idle throttle response to Slow or Very Slow. In the extreme you can do a servo slow function on the down going side of the throttle. I do that for not so good pumps that allow a lot of rpm overshoot below commanded idle rpm when going to idle.
Low Idle is a setting for reducing residual thrust and is achieved by moving the throttle trim lever down to half way between run and off. You probably don't need this. I use it on one particular airplane to help slow down. The risk is that you can accidentally shut off the engine when you move the trim. Might want to leave it set to the same as Minimum RPM.
The sputtering you hear is likely a problem with positioning of the fuel needles in the combustion chamber. I had a similar problem on a P-70 and a P-120. On my P120, the problem was largely on the ground and got better over time. But the P-70 did it inflight. I'm sure your local elevation / density altitude is part of the problem. Moving the stick slowly sometimes helps and conversely, a throttle slam to max sometimes gets you thru it fast enough not to be a problem. If it persists, you need to send it in.
Low Idle is a setting for reducing residual thrust and is achieved by moving the throttle trim lever down to half way between run and off. You probably don't need this. I use it on one particular airplane to help slow down. The risk is that you can accidentally shut off the engine when you move the trim. Might want to leave it set to the same as Minimum RPM.
The sputtering you hear is likely a problem with positioning of the fuel needles in the combustion chamber. I had a similar problem on a P-70 and a P-120. On my P120, the problem was largely on the ground and got better over time. But the P-70 did it inflight. I'm sure your local elevation / density altitude is part of the problem. Moving the stick slowly sometimes helps and conversely, a throttle slam to max sometimes gets you thru it fast enough not to be a problem. If it persists, you need to send it in.
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I did increase Idle to 35k. I changed the throttle response to normal(was on fast). Sorted the shut down when slamming the throttle close. Still had sputtering on the startup and accelleration. So I decreesed U-accel 1 and U-accel 2 . Must have done someting good because now it has a clean start, no sputtering on accelleration and no shut down on closing the throttle fast. Thanks Thud_Driver. As you said, I also think the high RPM setting is nessecary at our altitude.