Owning and Flying Over TBO

[AndyTowPilot]

Howdy!

How many folks are doing this? I flew quite a bit with a friend in an Aerostar that did this for years. His mechanics were on top of everything, the oil was sent out twice yearly and the compression was checked on the same schedule. Never an issue.

Of course, we know this means there is more risk, but I assume other folks are operating privately this way. Any experience, insights? Would especially like to hear from long time operators and A&P's.

Thanks,
Andy

 

[NoHeat]

I’m 300 hours beyond TBO and I love it. It feels like I’m getting something valuable at no cost.

Over the years, half of the cylinders in my big-bore Continental were replaced, along with the lifters, and a starter adapter. That’s all.

I’ll keep going further beyond TBO until my engine gives me a reason not to. For now I’m getting consistently clean oil filters and oil analysis reports at every oil change. Nothing of concern in the frequent Savvy reports on my engine analyzer data.

 

[wayneda40]

My DA40 (IO360, one real mag, one EIS) has 2600 tach hours (vs 2000 TBO)... I fly frequently (300+ hours/yr), do Blackstones every oil change, borescopes every annual, and as @NoHeat does, I also watch the Savvy reports. In 2600 tach hours, only replaced one cylinder.

 

[Clip4]

It depends on the specific plane, the specific engine and how the plane is maintained and flown.

 

[Racerx]

Usually your engine will tell you when it's time. I've never understood the 1800smoh but only 100stoh.

 

[Ventucky Red]

Knew one gent that use to fly his 152 from KLGB to KRAL just about every work day he could. He got close to 2,800 on the O-235 before it was telling him it was time for a change. I do think he may have changed out a jug or two, but still, pretty darn impressive, and goes to show what taking care or your equipment can do for you.

 

[RussR]

I am currently operating a Seminole for multi engine training that has 2400+ on each engine. And those are hard hours - almost every flight has one or the other shut down and restarted, sometimes multiple times. Lots of time near idle on one engine and full power on the other too.

 

[LesGawlik]

I think it's okay provided you borescope your valves, cut the filter and do the oil analysis. If you have 4 or 6 burned pizzas and low metal in the oil analysis and the filter, you're okay.

 

[wheaties]

Our mechanic says he will not pass anyone on annual who is more than 500hr over TBO. Something to do with liability. No pilot would sue the IA if something happened but I guarantee their insurance company plus family's lawyers would go after the guy.

 

[DGlaeser]

The training planes I fly (172s and a SkyCatcher) have breezed by TBO with no fanfare. We had a couple of 172 with over 4000 Tach hours on their original engines. The SkyCatcher I fly currently has over 3000 tach hours. The engine has good compressions and good oil analysis reports. These airplanes fly almost every day - usually multiple times a day. Regular use, even the hard life of a trainer, is the 'secret' to long life!
We've used a number of mechanics over the years, and I've never had one hesitate doing 100hrs/annuals on any of these planes...

 

[Bell206]

How many folks are doing this?

Out of my past customers over 50% flew past recommended TBO on average. Also knew a contract pipeline patroller who consistantly got 3000+ out of his engines. In my experience its more common than not.

we know this means there is more risk

Except risk is subjective to the person. Statistically there's risk with new engines as well. As mentioned above the "risk" is more tied to the specific aircraft/engine type and how it is operated/maintained. At least in my experience.

Something to do with liability. No pilot would sue the IA if something happened but I guarantee their insurance company plus family's lawyers would go after the guy.

Liability can be subjective as well. So some APIAs come up with their own rules which is their right if they want. However, there was nothing in any of my mx insurance policies that equated time limits. My policy did change in the early 90s that required a separate rider if I wanted to perfom heavy engine mx but even that didnt have any time requirement, etc.

Unfortunately once you get in the court room a mechanic can be held liable for anything the plaintiff chooses as it merely follows a "standard of care" definition vs the FARs.. For example, I know of several cases where the APIA was held liable for not "enforcing" the compliance of service bulletins even though it was not his regulatory or legal obligation. The problem is all the plaintiff needs to do is convice a judge or jury this is how it should be not what it really is.

 

[pfarber]

Out of my past customers over 50% flew past recommended TBO on average. Also knew a contract pipeline patroller who consistantly got 3000+ out of his engines. In my experience its more common than not.

Except risk is subjective to the person. Statistically there's risk with new engines as well. As mentioned above the "risk" is more tied to the specific aircraft/engine type and how it is operated/maintained. At least in my experience.

Liability can be subjective as well. So some APIAs come up with their own rules which is their right if they want. However, there was nothing in any of my mx insurance policies that equated time limits. My policy did change in the early 90s that required a separate rider if I wanted to perfom heavy engine mx but even that didnt have any time requirement, etc.

Unfortunately once you get in the court room a mechanic can be held liable for anything the plaintiff chooses as it merely follows a "standard of care" definition vs the FARs.. For example, I know of several cases where the APIA was held liable for not "enforcing" the compliance of service bulletins even though it was not his regulatory or legal obligation. The problem is all the plaintiff needs to do is convice a judge or jury this is how it should be not what it really is.

Care to cite a few so we can read up on them?

 

[Bill]

Mooney IO360 A3B6D TBO per the POH: 1800. Ours went to 2250 before it was time.

 

[Domenick]

I ran my last engine (O-320-D3G, NA) 924 hours over TBO. It was a Lycoming factory reman from 1996. Changed/analyzed the oil/filter, checked compression, rotated and serviced the spark plugs, and calculated oil consumption every 50 hours. No major issues until engine retired. All four Lycoming cylinders made it to the end.

 

[MickYoumans]

I flew the Lycoming 0-320 in my Cherokee to 2300 before overhaul. The engine will tell you when it’s time. In my case I started having compression issues. I ordered four new Lycoming complete cylinder kits to install on the plane. Doing that I knew that everything from the block out was new. Triad in Burlington NC performed the overhaul and replaced all of the bearings and any other gears and internal parts that did not meet the spec requirements. I have about 250 hours on my new overhaul. I don’t see any problem with owning or buying an airplane that is at or beyond TBO if you realize that at some point you will be faced with the overhaul and are prepared for that.

 

[Grum.Man]

I'd be less worried about an engine that's 500 hours over than one with 500 hours over 20 years. Catastrophic failure of an engine that's been in service that long is almost unheard of. It will give plenty of signs well before it is truly done for. As long as the oil is clean and pressure is good I wouldn't worry about the bottom end. Once you start getting metal in the system it's due for a total tear down.

 

[Kenny Phillips]

"On Condition" continuous MRO is what is done at higher levels anyway. It seems to work better on recips if you fly them quite regularly; corrosion is our enemy. We overhauled an engine with about 300 hours on it due to corrosion, then flew it more than a thousand before we sold it.

 

[kujo806]

I bought my Bonanza this summer at TBO. The IO520 is slightly over 1700hrs. Given the ridiculous lead times on everything these days, I went ahead and ordered a IO550 for it. I didn't want it to go belly up and be grounded waiting for a new engine or cylinders. That said, it is running like a top, and I feel kind of bad about ordering an expensive engine. Compressions are on the weak side, but it doesn't really use oil, the oil is perfectly clean at 35hrs, no leaks, and the plane will do 175+knts.

Mike Busch has a lot of good Youtube webinars on the topic. Basically if it is running well and oil analysis is good, he highlights that risk is actually lower to keep flying than do a very invasive engine overhaul / transplant and all the new unknowns that come with it.

 

[Bill]

I bought my Bonanza this summer at TBO. The IO520 is slightly over 1700hrs. Given the ridiculous lead times on everything these days, I went ahead and ordered a IO550 for it. I didn't want it to go belly up and be grounded waiting for a new engine or cylinders. That said, it is running like a top, and I feel kind of bad about ordering an expensive engine. Compressions are on the weak side, but it doesn't really use oil, the oil is perfectly clean at 35hrs, no leaks, and the plane will do 175+knts.

Mike Busch has a lot of good Youtube webinars on the topic. Basically if it is running well and oil analysis is good, he highlights that risk is actually lower to keep flying than do a very invasive engine overhaul / transplant and all the new unknowns that come with it.

Pickle the new engine when you receive it and run the old one until it's ready.

 

[Bell206]

Care to cite a few so we can read up on them?

A few of what? If the SB cases I no longer have access to those databases. However, there are a few legal articles out there written by attorneys that discuss this. One was Greg Reigel plus a couple guys from the west coast who also put on several seminars on the civil liability of mechanics come to mind. Even Mike Busch jumped on the liability bandwagon and wrote an article when this became big news way back then. I might have a copy somewhere and will post when I get home.

But in the meantime care to cite some of your maintenance credentials and experience so we can read up on those as well? We're still waiting

 

[Capt. Geoffrey Thorpe]

How is TBO determined and what does it mean?

 

[Huckster79]

Does the IA who won’t pass an annual if it’s beyond 500 over have an age limit over? the forgotten number in TBO.

I’d guess a majority of average birds at lil ol airports are well beyond 12 years ago… and hardly a soul seems to see that as past tbo.

condition, condition, condition. Overhauling a happy well running engine because of a number is foolhardy.

my lil continental was overhauled 22 years ago and 1000 hours, likely going to need new cylinders one of these days but till she tells me she’s ready she’s gunna stay put on the front of my bird, even though I’m 8 years past tbo.

 

[Blatham489]

All you guys bragging about how far over TBO you are, you’re in grave danger - of karma biting you in the ass. The Cirrus that just landed in the SC lake wrote in his ad on Controller “I’ve owned this plane for 18yrs and it’s never let me down yet”. He was at 2400+ Hobbs (so maybe 2000 tach). Just sayin. . . .



(my intent is to run with your same philosophy, but no posting about it)

 

[Grum.Man]

Pickle the new engine when you receive it and run the old one until it's ready.

Only problem with this is most Engine companies have warranties that start within some pre-determined amount of time once received. Usually it's 90 days from receipt or begins at installation. It would be a shame to let a new engine sit until it's warranty period is over only to have an issue when you install it.

 

[AndyTowPilot]

Thanks everyone, this has been hugely informative!! It really helps me to decide what might be a good candidate and what might not.

 

[kujo806]

Only problem with this is most Engine companies have warranties that start within some pre-determined amount of time once received. Usually it's 90 days from receipt or begins at installation. It would be a shame to let a new engine sit until it's warranty period is over only to have an issue when you install it.

It is definitely tempting, but there is also a core charge I would have to eat. I think it is like $16K if the core isn't returned in 90 days.

 

[nrpetersen]

To the OP - Your old engine sounds ideal as is for a homebuilt. An engine at TBO can probably withstand a lot more overheating etc abuse than a brand new one.

 

[WillFly4Food]

We had a club Bonanza go about 750 hours over TBO on a Continental IO520. Likely a result of excellent maintenance, oil changes every 50 hours, etc. This airplane also did some training time, so lots of pattern work, power off 180 landings, those kinds of things.

 

[WillFly4Food]

I don’t see any problem with owning or buying an airplane that is at or beyond TBO if you realize that at some point you will be faced with the overhaul and are prepared for that.

This is really an ideal situation if you want to upgrade to a different engine.

 

[mandm]

I bought my Bonanza this summer at TBO. The IO520 is slightly over 1700hrs. Given the ridiculous lead times on everything these days, I went ahead and ordered a IO550 for it. I didn't want it to go belly up and be grounded waiting for a new engine or cylinders. That said, it is running like a top, and I feel kind of bad about ordering an expensive engine. Compressions are on the weak side, but it doesn't really use oil, the oil is perfectly clean at 35hrs, no leaks, and the plane will do 175+knts.

Mike Busch has a lot of good Youtube webinars on the topic. Basically if it is running well and oil analysis is good, he highlights that risk is actually lower to keep flying than do a very invasive engine overhaul / transplant and all the new unknowns that come with it.

Continentals? Heard they generally have lower compressions. Should be >60s. For Lycoming compressions should be >70s. But this is also all new to me. As long as you fly regularly and oil changes regularly then I think you could probably get 500 over TBO, which could be several years depending upon how many hours you fly.

 

[kujo806]

Continentals? Heard they generally have lower compressions. Should be >60s. For Lycoming compressions should be >70s. But this is also all new to me. As long as you fly regularly and oil changes regularly then I think you could probably get 500 over TBO, which could be several years depending upon how many hours you fly.

This guy is 48-50 across the board which concerned me at first. Like I said though, it makes full power, doesn't use oil, and the oil stays nice and clean. That means there is not excessive blow by or valve guide wear. Good thing because Continental just delayed my 550 another few months!