Engine Times

[signu127]

If there are links please point me to them. I did a search and did not find what I was looking for....

I was wondering about times. When is a 172 or 182 "timed out" and what does that mean for a private owner. Also if looking to purchase a plane what does it mean for the prospective buyer if a planes TT is 3508 and 1199 SMOH. Is that engine good up to 2000 hours and can it be overhauled again considering there will be 4300 hours on the engine.

thanks

 

[flyingmoose]

If there are links please point me to them. I did a search and did not find what I was looking for....

I was wondering about times. When is a 172 or 182 "timed out" and what does that mean for a private owner. Also if looking to purchase a plane what does it mean for the prospective buyer if a planes TT is 3508 and 1199 SMOH. Is that engine good up to 2000 hours and can it be overhauled again considering there will be 4300 hours on the engine.

thanks

Short answer is as a private part 91 operator you do not have to comply with engine overhaul recommendations. When someone typically says that an engine is "timed out" they are referring to the TBO hours listed for that model. TT on the plane might be different than TT on the engine and obviously TT on the engine might be different that TSMO. Yes it does matter when you are looking to purchase an aircraft. Lower time engines are worth more. Yes you can overhaul it again and again, although you might have to change parts that are out of spec. Lots of owners run their engines well past TBO with no issues.

 

[Capt. Geoffrey Thorpe]

"Timed out" means that it has hit the book value for the hours for an overhaul.

However, for a private owner, this does not mean that the airplane turns into a pumpkin. But it does mean that you need to consider the potential for an overhaul at some point in the near future - exactly when is hard to say. How many years since the last overhaul? An engine that runs regularly is much more likely to make it well past TBO than one that flies once a month.

And, yes, it can be overhauled again. All it takes is money.

 

[docmirror]

Based on age since overhaul, about 99% of the GA private fleet are prolly 'timed out'. I think Lyc recommends 12 years, and I don't know what Conti says, but considering 75 hour per year after 12 years an engine would only have 900 hours on it. TBO would still be 1100 hours in the future. Of course, few people pay attention to the calendar hours, and the engines don't seem to be able to tell the date either, they run just fine at 12 years and one day provided they've been maintained.

 

[signu127]

That was something I meant to ask too...Years, I seen some planes that are 30 years old with 1200TT.

 

[Tom-D]

That was something I meant to ask too...Years, I seen some planes that are 30 years old with 1200TT.

Not a problem, years doesn't mean anything to metal.

The material condition all depends upon the care given in all those years.

I've seen 1 year old engines with severe corrosion, and engines well over 40 years old with none. it's all about care, usage, and storage facilities.

There is only 1 reason a part 91 operator would overhaul any engine, symptoms/discrepancies seen, causes the operator to not trust the engine's airworthiness.

 

[poadeleted21]

Not a problem, years doesn't mean anything to metal.

The material condition all depends upon the care given in all those years.

I've seen 1 year old engines with severe corrosion, and engines well over 40 years old with none. it's all about care, usage, and storage facilities.

There is only 1 reason a part 91 operator would overhaul any engine, symptoms/discrepancies seen, causes the operator to not trust the engine's airworthiness.

Years don't mean anything to metal but the window for exposures to negative circumstances is wider. There are parts in an engine not made of metal. 30 years SMOH raises tons of red flags. For a guy who can overhaul his own engines...more power to you. For a guy unsure about what SMOH means first line of defense would be to stay the hell away from a 30 year old overhaul hangar queen.

 

[C182P]

What everybody else said.

Also, 2000 is not a fixed number; there are different TBO's for different engines (and for different variations of the same engine). My engine has only a 1500 TBO but I'll get much more out of it if it's willing. For resale value, you can consider TSMO like car miles in that each one lessens the market value by some small amount -- but with aircraft engines, once your engine reaches TBO there isn't any further depreciation of market value (until you pay for the overhaul... then your money flies out the window with each hour all over again).

 

[docmirror]

Another consideration is that not all internal engine components are created equal. The parts with the fastest wear are the exhaust valve, guide, and seat. These components may only last 300-800 hours on some engines but it is no reason to perform a 'major' overhaul. It is just a inspect and repair as needed. The bearings in the crankshaft, and the rods may be good for 3000 or more hours. In some engines the rod bearings can be inspected or replaced with the engine in the plane as well.

 

[poadeleted21]

What everybody else said.

Also, 2000 is not a fixed number; there are different TBO's for different engines (and for different variations of the same engine). My engine has only a 1500 TBO but I'll get much more out of it if it's willing. For resale value, you can consider TSMO like car miles in that each one lessens the market value by some small amount -- but with aircraft engines, once your engine reaches TBO there isn't any further depreciation of market value (until you pay for the overhaul... then your money flies out the window with each hour all over again).

I would pay more for an engine at TBO vs one 1000 hours over. Vref might not punish you, but the market might.

 

[Tom-D]

Years don't mean anything to metal but the window for exposures to negative circumstances is wider. There are parts in an engine not made of metal. 30 years SMOH raises tons of red flags. For a guy who can overhaul his own engines...more power to you. For a guy unsure about what SMOH means first line of defense would be to stay the hell away from a 30 year old overhaul hangar queen.

Why wouldn't you take a look if the price is right?

I am restoring a 1948 C-170 that sat in storage in AWO from 1992 until last fall, It is a very straight airframe with very little corrosion, 1800 TT, the engine could have been flown with no problems, But I didn't trust it so we overhauled it, When done I will have less money in it than what it will be worth.

Your theory you would never taken a second look.

 

[poadeleted21]

Why wouldn't you tae a look if the price is right?

I am restoring a 1948 C-170 that sat in storage in AWO from 1992 until last fall, It is a very straight airframe with very little corrosion, 1800 TT, the engine could have been flown with no problems, But I didn't trust it so we overhauled it, When done I will have less money in it than what it will be worth.

Your theory you would never taken a second look.

That is correct.

I don't rebuild engines nor restore aircraft, I don't fly behind engines I don't trust and I'm not going to bend over backwards to buy an airplane from someone that has an issue that set off too many red flags. Having dealt with my share of mechanics and avionics folks, I prefer to stay out of large projects where the end result is only dependent on my ability to sign checks.

 

[Tom-D]

That is correct.

I don't rebuild engines nor restore aircraft, I don't fly behind engines I don't trust and I'm not going to bend over backwards to buy an airplane from someone that has an issue that set off too many red flags. Having dealt with my share of mechanics and avionics folks, I prefer to stay out of large projects where the end result is only dependent on my ability to sign checks.

Your way of thinking is why the fleet is shrinking, no one wants to spend the money to get a really nice aircraft or believe their sweat equity is worth anything.

I don't do this because I make money, I do this because there are many nice aircraft that need to stay in airworthy condition, and I like flying really nice aircraft.

 

[poadeleted21]

Your way of thinking is why the fleet is shrinking, no one wants to spend the money to get a really nice aircraft or believe their sweat equity is worth anything.

I don't do this because I make money, I do this because there are many nice aircraft that need to stay in airworthy condition, and I like flying really nice aircraft.

My way of thinking is the financially and mentally sound method to buying an aircraft. It just ain't worth the money or effort to buy a fixer upper for most of the 50 year old B/C/P aircraft folks here get around in.

OP doesn't know what SMOH means... do you think he has an A&P/IA cert? His only option to stay in the air is probably his checkbook, sweat equity not accepted. He'd be throwing out a bigger gamble than he has to on 30 years and 1200hrs SMOH.

FWIW. The day I picked my plane up, it had 4 SMOH on a few days old engine. Brand new prop, overhauled landing gear, all new rigging and $10,000 worth of "other stuff". I wasted many a $ looking at those 30 years SMOH engines and scratched them right off the list fairly quickly in my search. I wouldn't call my 52 year old "really nice" but all the big ticket items are covered and the panel gets me by.

Call me a little jaded when dealing with shops. The last 15 hour quote I got was started in April and finished up in October. Let me tell you how much fun it is to pay hangar rent (While my plane was sitting on the ramp outside the shop at another airport), insurance and watch annual months tick away while renting a beater Cessna 172 from the FBO.

 

[bnt83]

Notables right off the bat on high calandar time engines, like 20 years and older since major overhaul (SMOH).

1. Oil leaks
   • Cork & paper gaskets get hard, old, split or just fall apart, particularly rocker box, intake manifold gaskets etc.
   • Rubber products such as o-rings, crankshaft nose seals, induction tube rubbers, pushrod tube seals, fuel & oil hoses, accessory shaft seals (magnetos, starters, generators), diaphragms in fuel pumps and pressure carburetors, all age and eventually leak regaurdless of the metal conditions.
2. Corrossion of the steel engine fasteners is a quick easy way to estimate what the internals of cylinder bores may look like. Are the spark plug bodies all corroded? Corroded cylinders will use a lot of oil, evidenced by dark exhaust trails and of coarse adding oil all the time.
3. If the engine is old and rusty looking then the constant speed prop & prop governor (if equipped) could easily have internal issues as well, unless more recently repaired.
4. Engine mount vibration isolators, another rubber product, can be expensive to replace ($500 to $1,500 depending on the part #).

 

[denverpilot]

You got the legal and other rule-specific answers, I won't cover those.

I'll add this: When shopping for a typical used aircraft nowadays, keep in mind they're all 30+ and often 40+ years old.

Maintenance and care and feeding of them is becoming far more similar to say, maintaining a classic car that you like and want to run well and look good (inspect everything, know that parts wear out including things you wouldn't expect, interiors wear out, etc...)... than say, most folk's idea of "maintenance" on a modern automobile. (Dump new oil in it every once in a while and run it.)

Engines... it really helps to know the history of how it was handled (or manhandled and abused... or not) and whether or not it was used regularly, etc...

I wouldn't be squeamish about buying a "timed out" engine just by the TBO number, but like others have said, I'm probably not going to pay you much for it. If you're buying, keep that in mind.

On the other hand, if you are buying and have spare cash on hand, buying and overhauling/replacing an engine if you can get a low price for the rest of the airplane is a great way to know exactly what YOUR engine's history is, since you just bought it and paid someone that you (supposedly) trust to overhaul it.

And as Tom pointed out, that can go for the whole darn airplane if you have the time, money, and in Tom's case... the authority... to rebuild the thing from the ground up, or as needed on the condition of the parts.

Owning a 70's vintage airplane is quite similar to owning a 70's vintage car. What would you have to do to that 1968 Camaro to keep it in tip-top shape? Just in runnable but not "pretty" shape? Same types of things...

 

[Tom-D]

My way of thinking is the financially and mentally sound method to buying an aircraft. It just ain't worth the money or effort to buy a fixer upper for most of the 50 year old B/C/P aircraft folks here get around in.

OP doesn't know what SMOH means... do you think he has an A&P/IA cert? His only option to stay in the air is probably his checkbook, sweat equity not accepted. He'd be throwing out a bigger gamble than he has to on 30 years and 1200hrs SMOH.

FWIW. The day I picked my plane up, it had 4 SMOH on a few days old engine. Brand new prop, overhauled landing gear, all new rigging and $10,000 worth of "other stuff". I wasted many a $ looking at those 30 years SMOH engines and scratched them right off the list fairly quickly in my search. I wouldn't call my 52 year old "really nice" but all the big ticket items are covered and the panel gets me by.

Call me a little jaded when dealing with shops. The last 15 hour quote I got was started in April and finished up in October. Let me tell you how much fun it is to pay hangar rent (While my plane was sitting on the ramp outside the shop at another airport), insurance and watch annual months tick away while renting a beater Cessna 172 from the FBO.

And you probably have the fat wallet to support your thinking, many don't, so sweat equity means a lot

 

[poadeleted21]

And you probably have the fat wallet to support your thinking, many don't, so sweat equity means a lot

And you probably have a A&P/IA cert, many don't so sweat equity doesn't mean !@#$%.

 

[docmirror]

Maintenance and care and feeding of them is becoming far more similar to say, maintaining a classic car that you like and want to run well and look good (inspect everything, know that parts wear out including things you wouldn't expect, interiors wear out, etc...)... than say, most folk's idea of "maintenance" on a modern automobile. (Dump new oil in it every once in a while and run it.)

Owning a 70's vintage airplane is quite similar to owning a 70's vintage car. What would you have to do to that 1968 Camaro to keep it in tip-top shape? Just in runnable but not "pretty" shape? Same types of things...

Well written. I own several vintage cars, and the upkeep is quite similar to a vintage aircraft, it's just that we don't think of a 1969 C172 as a vintage plane, we just call it a plane. I spend plenty of hours tinkering with my vintage cars because things wear out.

 

[Tom-D]

And you probably have a A&P/IA cert, many don't so sweat equity doesn't mean !@#$%.

You don't need any certification to work on aircraft.

just a friendly A&P who will supervise your work.

I do it all the time for my customers that do their own maintenance.