Crankcase breather tube in pitts
Posted: Mon Jan 08, 2018 10:52 pm
Hi all,
Today I landed my pitts half covered in oil (right side has oil everywhere). The oil seems to originate from the hole I drilled into the crankcase breather tube (
thanks to some interesting info posted by Colondel Sanders: http://www.pittspecials.com/articles/CrankBreather.htm)) and also dripping heavily out of the actual breather tube at the tail. Outside air temperature was around -8 celcius. After about 15 minutes of aerobatics I noticed a weird vibration. I have felt weird vibrations before for no reason, so I thought I would have been imaginging things, after all, something always vibrates. A minute later I smelled something funny. A faint fire smell, but no smoke. Like a campfire smell but not the burning plastic smell. Time to land... Spotted a moose on final (that was nice) and landed. In the circuit the plane behaved normally. After landing I decided to check the cowling. Opened the left side, all looked normal. Walked around to the right side and there was oil on the fuelage, wings, tail. Everywhere. Yikes.
Opened up the cowling and the oil seemed to come out of the hole in the crankcase breather tube (half inch oil covered with electrical tape with a razor blade cut in it). There was no oil leak around the engine or before the engine. Lots of oil on the firewall (right half) Hoping the crankshaft seal is still ok. Called some mechanics and people in the known. The most obvious thing would be that something froze in the breather tube. If that's the case, I don't understand why the breather tube was dripping oil after landing. I did notice some slush at the end of the tube, and a lot of oily slush on the tailwheel assembly.
What I don't understand: IF the breather tube was actually frozen, and the hole I drilled took over, why is there soo much oil leaking? About half a quart I would estimate. On a normal flight, it hardly spits out any oil. Would this cause a vibration somehow?
The burning smell was probably the oil hitting the hot exhaust, as oil was also dripping on there.
Anyway, I'm not flying untill my mechanic takes a look, but since it's my lovely buttock on the line, I'm trying to find out more information...
Regards,
digits
Today I landed my pitts half covered in oil (right side has oil everywhere). The oil seems to originate from the hole I drilled into the crankcase breather tube (
thanks to some interesting info posted by Colondel Sanders: http://www.pittspecials.com/articles/CrankBreather.htm)) and also dripping heavily out of the actual breather tube at the tail. Outside air temperature was around -8 celcius. After about 15 minutes of aerobatics I noticed a weird vibration. I have felt weird vibrations before for no reason, so I thought I would have been imaginging things, after all, something always vibrates. A minute later I smelled something funny. A faint fire smell, but no smoke. Like a campfire smell but not the burning plastic smell. Time to land... Spotted a moose on final (that was nice) and landed. In the circuit the plane behaved normally. After landing I decided to check the cowling. Opened the left side, all looked normal. Walked around to the right side and there was oil on the fuelage, wings, tail. Everywhere. Yikes.
Opened up the cowling and the oil seemed to come out of the hole in the crankcase breather tube (half inch oil covered with electrical tape with a razor blade cut in it). There was no oil leak around the engine or before the engine. Lots of oil on the firewall (right half) Hoping the crankshaft seal is still ok. Called some mechanics and people in the known. The most obvious thing would be that something froze in the breather tube. If that's the case, I don't understand why the breather tube was dripping oil after landing. I did notice some slush at the end of the tube, and a lot of oily slush on the tailwheel assembly.
What I don't understand: IF the breather tube was actually frozen, and the hole I drilled took over, why is there soo much oil leaking? About half a quart I would estimate. On a normal flight, it hardly spits out any oil. Would this cause a vibration somehow?
The burning smell was probably the oil hitting the hot exhaust, as oil was also dripping on there.
Anyway, I'm not flying untill my mechanic takes a look, but since it's my lovely buttock on the line, I'm trying to find out more information...
Regards,
digits