Oil Leak

How much oil is, safe to loose?.

An aircraft I looked at had a considerable wet oil smear under it's belly from the engine,

Not only there but also on the ground beneath it, pilot said " it's from the last oil & filter change", but was still dripping after the 30min flight returned. (Commercial sightseeing).

spacesailor

I would say it is not safe to lose any oil. But if that was just the remains of spilled oil it is more a case of how well is the maintenance being done. If I found oil leaking or smeared over an engine I would want to know where it came from and was it still coming out. That would entail a clean up and an engine run at the very least.

Make a decision not to fly with that operator.

It depends ...

if its a half VW (your profile is Hummelbird) then the breather and oil catcher is doing a lot of work,

if its a Jab and its been overfilled then its gonna have an oil smear,

if it s a full VW then it should have pretty much none

If its a R912 then again nil is the acceptable smear in everything other than an aerobatic installation

If it's a big old round engine then just accept that your oil supplier is going to know your face well

Oh and if it were a two stroke (I know its not) then it bloody well better have a decent oil smear

Did you locate the position of the oil filter? If the oil smear is forward of that location, up goes the big red flag. Look further.

An air-cooled engine of any type or use is expected to use some oil in its normal operation. Without too much precision, I'd suggest that half a litre after about 15 hours training flying would be OK. Much more and I would be poking around to find leaking seals, or doing a chimney sweep of the exhaust pipe to see what muck was up there.

OME

How about a BIG 8 seater Cessna! (8Pax),

No it was running from the engine firewall for a couple of metre's back under the fuselage, then dripping onto the ground below. After a return flight it was still dripping.

I wouldn't have 5oomils in my "MoslerMotor" ( 1/2VW ) So can do an oil change every week out of a 5lt can of oil, if I wanted!,

spacesailor

If it came from an oil change, how was it on the firewall. That is not the usual position for oil to be taken from the engine, nor is it usual for oil to get there from overfilling. I suppose it could have come from a rear mounted oil filter, but that should have been cleaned up.

I consider it is good airmanship to keep track of any oil coming from the engine so wiping up any spills is essential and crankcase blowby is usually collected and diverted to somewhere away from the engine, but I wouldn't think the firewall was an appropriate place,

Some blowby gets onto the belly of my planes, but I have never seen it wet and dripping.

It shouldn't be normal. If it's from the breather, possibly a compression check will find poor ring sealing, otherwise it's leaking from somewhere and should be rectified. An oil leak can be a fire hazard as well. Nev

I've known a couple of Lycoming's that if filled full will promptly throw a couple of quarts out then settle down to normal oil use. If next pilot checks oil & decides its low, adds a quart. Process is repeated. I just put it down wrong dipstick.

Had a case here where a pilot was distracted during preflight, forgot to tighten dipstick then proceeded to do an aerobatic routine, returned with very little oil in the sump, now that was messy, but lesson learnt.

Hi All nice people , If never before had seen a such problem on your engine and all is began since your last service , so start to check your Oil filter and Drainage Screw where probably you will meet your answer , before all clean your engine with dry paper , once you don't observe any oily part , run your engine and let it just 5 minutes with idle speed then stop engine and lets tempering the engine for a 5 minutes then control newly all parts , you will certainly meet the sources of leakage then depends on what you meet we can decide for a repair

But before all never use a level higher than your Aircraft Engine standard , other matter is some Boxer Engines which we call dry span should be refiled and controlled by engine running on idle speed which permit to use the needed oil in all engine circuits which means Oil filter Oil cooler radiator Oil tubes with circuit in pressure , Good Luck

Hi Linz

It's not my aircraft but one taking joyriders for expensive sight-seeing trips,

And welcome.

spacesailor

Hi LinzIt's not my aircraft but one taking joyriders for expensive sight-seeing trips,

And welcome.

 

spacesailor

How much oil is, safe to loose?.An aircraft I looked at had a considerable wet oil smear under it's belly from the engine,

Not only there but also on the ground beneath it, pilot said " it's from the last oil & filter change", but was still dripping after the 30min flight returned. (Commercial sightseeing).

 

spacesailor

Not a lot of "Radial" Cessna's caravans around!

spacesailor