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Oil on ground under your aircraft

You find a puddle of oil 3" X 5" under your aircraft after you land. What do you do?

  • Get back in the aircraft and fly 17.5 NM home?

    Votes: 8 4.3%

  • Make a post to VAF asking what to do?

    Votes: 3 1.6%

  • Phone your A&P Mechanic?

    Votes: 0 0.0%

  • Pull cowl and investigate?

    Votes: 170 91.4%

  • Find an A&P to investigate?

    Votes: 1 0.5%

  • Other?

    Votes: 4 2.2%
  • Total voters
    186
  • Poll closed .
RV6_flyer

RV6_flyer

Well Known Member
Benefactor
You’re out flying meeting your buddies for lunch. After lunch on your way home, there is a rainstorm at your home airport. You divert to a nearby airport to visit friends so that there is time for the storm to pass. When you get out of your aircraft, you find a puddle about 3” X 5” of oil under the airplane and it is coming from cowl exit. Oil is noticed by the air inlet in front of the #2 cylinder. Pulling the dipstick, the oil is down ¾ of a quart from what it was when you took off 1.1 hours earlier. What do you do?
 
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maybe need to clarify a bit.

Are you saying from the time you landed ,parked and got out (what 5 minutes max?) you have a 3X5 puddle under the airplane in that amount of time?

Or was there considerable amount of time the airplane was sitting?
 
RV6_flyer said:
You?re out flying meeting your buddies for lunch. After lunch on your way home, there is a rainstorm at your home airport. You divert to a nearby airport to visit friends so that there is time for the storm to pass. When you get out of your aircraft, you find a puddle about 3? X 5? of oil under the airplane and it is coming from cowl exit. Oil is noticed by the air inlet in front of the #2 cylinder. Pulling the dipstick, the oil is down ? of a quart from what it was when you took off 1.1 hours earlier. What do you do?
Click to expand...

Pull the cowl, look for the leak. Depending on the source, repair the leak on the spot, add oil fly home and make repairs, or ground the aircraft if the repair isn't fixable or the problem isn't flyable.
 
Lift the top cowl and have a look to see where it's coming from. And the bottom if needed. If your at a friends, he has a hangar right? Could be just a rocker cover gasket or return line hose and a 5 minute fix if you are lucky. A nose seal or governor gasket if you are not as lucky. You are lucky to find it on the ground in any case.

So what did you do and where is your leak?
 
ijustwannafly said:
maybe need to clarify a bit.

Are you saying from the time you landed ,parked and got out (what 5 minutes max?) you have a 3X5 puddle under the airplane in that amount of time?

Or was there considerable amount of time the airplane was sitting?
Click to expand...

Puddle was under the airplane when you got out. After engine shutdown, you wrote down hobbs and tach time and got out to find the puddle.
 
Oil is the engine's blood. That much coming out in that short a time? Definitely warrants investigation.
 
been there, done that

Once preflighting my Citabria, I noticed a puddle of oil and it was dripping from the cowl exit. Airplane had been parked for a week, but still, not normal.

Looking inside the dipstick access door, I could see a trail of oil running down the side of the case, coming from the pipe fitting where the mechanical oil pressure gauge line connected. I pulled the top cowl, grabbed that fitting and it broke off in my hand. That fitting had a pin-hole orifice so that oil would not be lost fast if the gauge line broke. But that was no help in this case, the fitting was broken at the base of the threads. Would have pumped oil out fast.

You don't know how bad it is until you find it and look at it. Gotta pull the cowl and have a look-see.
 
Probably your crankshaft seal leaking but need to pull the cowl and make sure. Best to fix your problem on the ground where you are then to press on with hopes of making it home .
Cheers
Pete
RV6A
 
I see most folks would pull the cowl to investigate.
One thing to consider, you are not at your home airport. You have no tools and no proper place to do a genuine inspection. A puddle this size is going to probably be something serious. IMHO there is no point pulling the cowl with no tool and no proper working environment to tackle a problem that is most likely large scale. I noticed I'm the only one that (so far) that said find an AP
I still stand by my decision because an AP will have suitable tools and a suitable location to do a proper inspection and I'm sure will not mind you watching / helping

Then once you find the issue you can tackle it properly. No point in pulling the cowl only to say to yourself "Yep that sucks guess I'm going nowhere"
 
you're right, but hey, we're guys eh?

Rob is right, just like the folks who pull their car to the side of the road, and open the hood! ( 'check engine light' TOLD them to!!!!...yup, engine is STILL there!!)...what ARE you really expecting to find?

Well I guess there's no HARM in popping off the cowl.
Let's say you just added oil before the flight, and you can see that the oil you spilled has just now, with heat & slipstream, found it's way to the rear outlet of the cowl. (deduction; yes, I'm a slob.)

OP: but with the loss of 3/4 qt. obviously this is something else....unlikely, but not impossible, to rectify with an adjustable crescent and Phillips screwdriver, tie wire, duct tape, hose clamp, etc.
Some of the mechanics out there might say this is exactly what happens when you split the o-ring on the dipstick, or overfill the oil, or do a few rolls causing massive blow-by.
 
"Do the Math"

3" x 5" puddle is a really small amount of oil---------in the tablespoon ish realm.

Was there a big streak of oil on the belly also??? If you actually lost 24oz of oil, it went somewhere other than on the ground.

You lost 24 oz in 1.1 hours, or apx 22 oz per hour.

You are 17 miles from home-----------6 min?? taxi time another 9 or 10??? total of 15--16 min???? Call it a quarter hour.

At the rate you used the oil when you noticed the issue, you would only use another half pint or so.

Fly it home.
 
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Oil puddle...

I agree with Mike S. that is a fairly small puddle, but for a short time frame that is a LOT of oil. I would look for oil elsewhere on the plane (belly, side of fuselage) then pull the cowl and investigate. But I am an A&P, and built my plane. Plus I never fly without enough tools to pull the cowl or make other minor repairs. However depending on the cause of the leak, you may have big decisions to make. Like The cracked crankcase in this event, I would not fly it home either.
 
Mike S said:
3" x 5" puddle is a really small amount of oil---------in the tablespoon ish realm.

Was there a big streak of oil on the belly also??? If you actually lost 24oz of oil, it went somewhere other than on the ground.

You lost 24 oz in 1.1 hours, or apx 22 oz per hour.

You are 17 miles from home-----------6 min?? taxi time another 9 or 10??? total of 15--16 min???? Call it a quarter hour.

At the rate you used the oil when you noticed the issue, you would only use another half pint or so.

Fly it home.
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You're assuming the problem was present at the start of the flight and the oil was lost gradually over the 1.1 hours. The problem could have occurred just before the end of the flight and the oil could be lost rapidly in the flight home.
 
beav said:
You're assuming the problem was present at the start of the flight and the oil was lost gradually over the 1.1 hours.
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Yes, I am.

That is why I italicized the words "At the rate"
 
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You guys do realize that this is a trick question and that there will be a dramatic ending soon. Condor just wants to see you squirm a little longer :).
 
scard said:
You guys do realize that this is a trick question and that there will be a dramatic ending soon. Condor just wants to see you squirm a little longer :).
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Yep, that is why I took the devils advocate stance
msn-emoticon-fishing-175.gif
 
beav said:
You're assuming the problem was present at the start of the flight and the oil was lost gradually over the 1.1 hours. The problem could have occurred just before the end of the flight and the oil could be lost rapidly in the flight home.
Click to expand...

I would never fly a plane that had a known oil leak. Why would anyone that's not behind enemy lines risk a smallish problem becoming a critical problem in the air!?
 
Cause

Oil leaks MAY be cause to ground it. Definitely cause to investigate. Find out, then decide. Anyone can inspect, making determinations on the other hand....
 
I wouldn't assume a small leak is going to stay small, until I see where it's coming from. What could have started as a small leak under low power could blow out altogether under high power when you take off. I don't fly anywhere without enough tools to remove the cowl... So investigation is my vote.
 
RV6_flyer said:
You?re out flying meeting your buddies for lunch. After lunch on your way home, there is a rainstorm at your home airport. You divert to a nearby airport to visit friends so that there is time for the storm to pass. When you get out of your aircraft, you find a puddle about 3? X 5? of oil under the airplane and it is coming from cowl exit. Oil is noticed by the air inlet in front of the #2 cylinder. Pulling the dipstick, the oil is down ? of a quart from what it was when you took off 1.1 hours earlier. What do you do?
Click to expand...

Gary,

An oil leak of this magnitude with a Lycoming engine has to be repaired before flight.

What is the point of doing a poll on it?
 
I once found a "small" oil leak. Heck, it didn't even drip on the ground. I found it while doing a preflight with a flash light in a dark hangar. It was a small amount, maybe half a teaspoon, on the right cowl inlet lip. Small, but unusual. I pulled the top cowl and and found the problem immediately... A broken crankcase thru-bolt! The nut and the remaining piece of the bolt were still sitting on top of the inter-cylinder baffle.

You must pull the cowl and inspect before further flight. She's talking to you and you need to listen.

Jerry Esquenazi
RV-8 N84JE
 
ijustwannafly said:
I see most folks would pull the cowl to investigate.
One thing to consider, you are not at your home airport. You have no tools and no proper place to do a genuine inspection.....
Click to expand...

My plane ALWAYS has the basic tools to do some things: change a spark plug, add brake fluid, change an inner tube, and obtain access to do these things. I regard that kit as part of the minimum required equipment.

The OP wouldn't have bothered mentioning this if it wasn't an unusual experience for him; his engine doesn't normally leak oil. Therefore, there's an anomaly. Better see what's going on. Might be easy, might be hard, might be safe to fly home, might not be. Better to know on the ground, and if it's my plane, I'd sure find out.

Wouldn't be the first time I'd pulled a cowling away from home.

Certainly, if you need more capability or expertise than you have with you, get that A&P. If there's one available at that airport.

Dave
 
I might move the plane a few feet away, and see if it is still leaking. Maybe I parked right on top of an existing puddle.

Scared myself with my car once on that one.
 
@ Scard - Yea some do not realize who Condor is. I know the answer but it is a trick question ... well sort of. It happened to him.
 
oil leak ! and was serious! under cowl!

okay.. I flew 30 miles to a local airport and noticed oil comeing from under neath my cowl and running down the belly.. so I can tell you from experience pull the cowl .. look for were the leak is comeing from Because it can be something serious .. in my case.. broken piston! and compression was pushing all my oil out my case vent.. so pull the cowl for sure.. I live by Murphy's law for sure! ;)
 
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