MNSUpilot
Well-Known Member
Hey all,
Had an interesting 'issue' in our Citation Ultra today. I'll do my best to put out all the details to provide a decent picture of what was going on. Talked to a few people in the last couple hours and have heard the possibility of a bearing going bad more than once. Thoughts?
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The first indication of anything abnormal was on the leg from BJC - EGE. We were at FL200 in moderate icing, at 180kias (~75%N1), all anti-ice on with lights out. We got a low groaning sound, from what I thought was the right engine, that stayed constant at a given power setting or would grow louder or disappear with small power changes. A few minutes later we got the descent into EGE and never heard another sound on the way in. Our only assumption was a bit of ice on a fan blade that was pronounced at higher RPMs. We checked on the ground and found no sign of ice or ingestion of anything in front of or on the fan itself of either engine. Both fans spun freely on the ground at EGE with nothing abnormal. (temps well above freezing)
We left EGE enroute to home with nothing abnormal on the takeoff roll with an N1 setting of right around 96%. We climbed through a little visible moisture starting at FL210 with the initial temp of -12*C with anti-ice on and lights out. Captain and I both started to notice what felt like an engine vibration. It wasn't violent, but enough to be uncomfortable and noticeable. I believe our climb power stayed in the 96-97%N1 area until we began pulling it back to reduce the vibration. A passenger did come up and ask what it was coming from and described it as a flutter-type feeling from the back. We kept reducing power to eliminate the vibration and it ended up disappearing at 89%N1. Due to the reduced power, we leveled off at FL370 at kept the power at 89% for quite awhile. We came up with the following numbers at FL370 with a temperature of -37*C while in an effort to increase power to climb up to FL390, although we ultimately stayed at FL370. Power was increased to 97%N1 initially with no vibration noticed but a large difference in ITT, with oil pressure and temperature staying the same.
97%N1 ITTs
Left Engine- 660 / Right Engine- 580-590
Power was reduced to 95%N1 and we recorded the following numbers:
95%N1
ITT -- Left Engine- 630-640 / Right Engine- 580
Oil Press -- Right- 84 / Left- 84
Oil Temp -- Right- 73 / Left- 67
Fuel Flow -- Right- 640 / Left- 620
We cycled the engine anti-ice switches and got the expected ITT rise equally on both engines. The right engine ITT always seemed to increase or decrease a fraction of the amount compared to the left engine with power changes with the thrust levers.
Thanks for the help!
Had an interesting 'issue' in our Citation Ultra today. I'll do my best to put out all the details to provide a decent picture of what was going on. Talked to a few people in the last couple hours and have heard the possibility of a bearing going bad more than once. Thoughts?
---
The first indication of anything abnormal was on the leg from BJC - EGE. We were at FL200 in moderate icing, at 180kias (~75%N1), all anti-ice on with lights out. We got a low groaning sound, from what I thought was the right engine, that stayed constant at a given power setting or would grow louder or disappear with small power changes. A few minutes later we got the descent into EGE and never heard another sound on the way in. Our only assumption was a bit of ice on a fan blade that was pronounced at higher RPMs. We checked on the ground and found no sign of ice or ingestion of anything in front of or on the fan itself of either engine. Both fans spun freely on the ground at EGE with nothing abnormal. (temps well above freezing)
We left EGE enroute to home with nothing abnormal on the takeoff roll with an N1 setting of right around 96%. We climbed through a little visible moisture starting at FL210 with the initial temp of -12*C with anti-ice on and lights out. Captain and I both started to notice what felt like an engine vibration. It wasn't violent, but enough to be uncomfortable and noticeable. I believe our climb power stayed in the 96-97%N1 area until we began pulling it back to reduce the vibration. A passenger did come up and ask what it was coming from and described it as a flutter-type feeling from the back. We kept reducing power to eliminate the vibration and it ended up disappearing at 89%N1. Due to the reduced power, we leveled off at FL370 at kept the power at 89% for quite awhile. We came up with the following numbers at FL370 with a temperature of -37*C while in an effort to increase power to climb up to FL390, although we ultimately stayed at FL370. Power was increased to 97%N1 initially with no vibration noticed but a large difference in ITT, with oil pressure and temperature staying the same.
97%N1 ITTs
Left Engine- 660 / Right Engine- 580-590
Power was reduced to 95%N1 and we recorded the following numbers:
95%N1
ITT -- Left Engine- 630-640 / Right Engine- 580
Oil Press -- Right- 84 / Left- 84
Oil Temp -- Right- 73 / Left- 67
Fuel Flow -- Right- 640 / Left- 620
We cycled the engine anti-ice switches and got the expected ITT rise equally on both engines. The right engine ITT always seemed to increase or decrease a fraction of the amount compared to the left engine with power changes with the thrust levers.
Thanks for the help!