Loss of an engine
 

Sometimes, and hopefully all the time, the loss of an engine is something we train for but never have to actually use. Well after 35 years of flying, I had my first engine out. I took off Sunday with the intention to visit a number of airports for the MnDOT aviation passport program. I left the Austin, MN airport where I keep the plane in the winter and landed at Owatonna. About 10 min after taking off from Owatonna I noticed my oil pressure on the rear engine dropping, and then bouncing from just above 0 to the bottom of the green line. I made the call to shut off the rear engine and secure it.

The flight from that point back to Austin was about 12 min. It was a quieter 12 min than normal with a lower airspeed but tracking solidly at 3500'. Greased it in back at Austin. I felt totally comfortable and didnt think twice about my actions. The plane flew hands off and going through the check list was a piece of cake.

Something let lose in the oil system, had oil everywhere inside the cowling and on the outside of the plane.

As they say, bad things come in 3's:

1. loss of an engine
2. The tremendous oil loss was on the main wheels. After touchdown, and on the roll out and breaking, the tire rotated on the wheel shearing off the valve stem and giving me a flat tire which is interesting at 50 mph- had to put on a loaner on the taxiway to get it to the shop
3. 5 planes in the shop ahead of me.....3 of which have no engines. Mechanic said I will be grounded till around February......

The single engine flying was amazing and actually pumped me up about the abilities of the Skymasters. The whole ordeal was a nonevent and I struggled way more with the flat tire than the loss of the engine. I love them!!

Fine job Tom. Bummer about the failure but yes, this is why I own my SkyMaster for 19 years and counting. They do offer reassurance in the event of the failure you just experienced. Good luck with the repair and please report back what actually caused it.

Thanks,

Ed

Good job Tom - and thanks for sharing. Glad to hear that you stayed focused and professional with the engine shutdown. Look forward to hearing of the cause.
Jeff

Were you able to fully feather your prop? (I keep wanting to ground test my feathering mechanism, achieve full feather, but they have it designed so you can’t do that.)

Good on you for keeping the oil pressure gauges in your scan. You may have saved yourself a much larger bill.

I'd be willing to bet your leak is a pretty simple fix. I'd bring in another A&P before I let my airplane sit for three months because the one shop is backed up!

oil pressure
 

Tom - super glad to hear it worked out to be a "non-event". I have a T337C and had an eerily similar situation. Turns out that it was the little oil feed line going into the top of the turbo on the rear engine. You might check to see if yours is cracked or has a hairline fracture. If so, voila - less downtime. BUT, do not just replace it with the same part number. The newer model T and P planes came with a stronger more reinforced feed oil line to the turbo. It is legal to upgrade to that part....also make sure you change out the check valve if you replace that line, with the newer check valve.

In any case - fantastic news that all is well. Better to be on the ground wishing you were in the air, than in the air wishing you were on the ground : )

follow up
 

Thanks for the comments! To follow up with some of you:

1. Mine is normally aspirated so no turbo oil line

2. Yes, the prop fully feathered. The plane almost leaped forward as soon as the prop feathered.....the drag was VERY noticeable. I can see why you gotta get them feathered ASAP on an engine loss on take off.

3. Mechanics are slim pickens around here no others at this airport and no way to get it to another airport.....and the places I am familiar with at those airports are backed up as well. My best shot would be a "mobile mechanic" and I havent heard of any around here, but it is something to look into. However, with the holidays and winter coming (lots of snow up here typically) it doesn't bother me too much. I have access to a 172 so I will still be able to get in the air. I like living in the rural part of the country, but it does have its drawbacks.

4. Based on the amount of oil lost in short order, it would seem to be on the pressurized system unless there is a gaping hole in the case, which I doubt - the engine was running normally otherwise. All of the oil is on the passenger side, and I am thinking oil cooler. I have Air Wolf remote oil filters front and back, so nothing related to the F and M oil filter adapter - and besides, that unit would be located on the other side of the engine where there is only residual oil from the other side.

5. Engine instruments are part of my scan. Its never more than a few min between flying and looking at the engine instruments and fuel levels. My pressures and temps are rock solid and the pretty much the same all the time. So it is very noticeable to me when something is off.

We have snow forecast for Friday, so he will not be busy fueling planes this weekend and I offered to help him out with both my plane and his backlog. He took me up on that so hopefully will be starting with him this weekend. I would at least like to get it degreased and get the side and top cowls off and really take a closer look and see if we can see anything obvious and go from there.

I will keep the group updated as things progress.

My guy is also solo. (Although another with his own customers just entered the shop.) nothing would get done if I solely counted on him. He’s covered up. And they consider the skymaster weird, different and difficult bird. (I see that, can’t memorize it like a 172 seen over and over again.) Fortunately he’s not too bashful taking care of a couple warbirds with very unique problems. So the deal is I launch in and do the work. I compensate (without him asking) even if he doesn’t touch it, for oversight and keep him in the loop but try not to slow him down. These guys are getting farther and farther between. The young crowd doesn’t seem to want to do it.

Perhaps it came in 4's. You always hope for the front engine to be the failed one...

Having said that, your tale certainly inspires (kudos and) confidence that either can be a "nonevent".

Well done Tom! I wish for airplane a speedy recovery!

Thinking out loud here. You say you shut down engine at bottom of the green oil pressure which should be adequate lube. No mention of engine running badly. You didn’t say if committed to a tear down. If find oil leak and repair it, maybe a really good inspection (with good results) will get back up and going sooner than February? Perhaps a quick decision point would be pulling the filter this weekend and looking for metal. Then checking for cracks (case, cylinder). Might quickly categorize as major vs a leak repair and back into the air sooner.

update
 

To clarify, my oil pressure had dropped to the bottom of the green and was then bouncing between about 10 psi (there is no "10 psi" indication, but it was just above 0) and the bottom of the green.

On the advice of one of the other members I am working with the mechanic for me to do the work and he will look over my shoulder. I will be starting work on it next weekend starting with the oil cooler and oil pressure line. Based on the rate of oil loss (4 quarts in about 6-7 min) it has to be a pressurized part of the system OR a monstrously large hole in the case. All the oil is from the back half of the engine so it is not the crank seal or the prop governor system and the rear engine does not have an unfeathering accumulator. I am hoping for a smoking gun - cracked oil cooler/blown gasket. I doubt it is the oil pressure line as that is small and the gauge was still working, albeit low and fluctuating.

Even if I have to pull the engine, me working on it with his assistance will get it hammered out before he would be able to get to it.

I have rebuilt a lot of hot rods and bracket drag cars and no less than 25 car engines, so I am not a stranger to a wrench and safety wire and reading a maintenance manual, so this is easily in my wheelhouse. In fact it kills me that I cant legally change my own starter!!!

I will keep the group up to speed on what I find out!

My experience be it correct here or not.....if the rear engine alternator nuts ever come loose, the alternator will drop and let the oil out, just throwing it there.....happened to me IN MEXICO.

Excellent! Another easy thing to check, thanks for the insight!!!

Does your bird have the engine access hatch in the rear firewall? I've heard of A&Ps that didn't know it was there and caused themselves lots of extra work. Use it if you've got it!