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Limit time for aircrafts (and M20J above all)


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Hi everyone,


 


so here come a pretty newbie question...


as i'm plannign to buy an M20J in the coming years, i already look at ads and all and i obviously have questions that pop from time to time.


Some i found answers to , others not so easily. Please note that being in EASA land maybe rules are different on some points ?


 


So about maintenance costs regarding limit times :


engine use TBO : 2000h then need OverHaul or replacement.


engin life span regardless of TBO :  ??  then needs ??


 


propeller use TBO : 1500 or 2000h or maybe no TBO (depending on brand and model) then needs OH or replacement


propeller life span regardless of TBO : ?? then needs ??


 


Then, are there other TBOs or life spans that need to be monitored and need maintenance ? I'm thinking airframe ?


 


These questions have arisen when i noticed some low use time M20J (since OH) but with long calendar periods, so i'm thinking even though the engine has 300h, as it's 10 y.o. it will need OH way before TBO ?


 


Thanks in advance for your help !


Pierre

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Pierre, in the US, a FAR part 91 operated (not for commercial use) aircraft TBO's are not compulsory.  EASA may be.  Discussing recommended TBO,  Lycoming's recommended TBO is 12 years or 2,000 hours.  Per McCauley SB137W, the M20J B2D34C214 McCauley prop (M20J) has a TBO of 72 months or 2000 hours.  OH cost is ~2300$ in the USA.  (Hartzell IIRC is 12 years-2000hr) The governor (Ours is a McCauley C290D) has a TBO of 1800 hours or 60 months). OH cost is ~6-800$ in the USA.  You may be affected by these from a regulatory standpoint. It pays to know.


The airframe itself has no life limit. It is strictly a valuation and marketing issue. Others disagree, but I have flown small GA airplanes with 25,000 hours on them. One Cessna 401 had 35,000 hours.  The engine, from what I have leaned over the years, will run 2 to 4 overhaul cycles (~4 to 8K hours) before either the case is milled to limits or the crank cannot be machined further.  At which point, you are looking at a huge replacement bill, 4-6K for either item. We were told 8-10K for an IO-360-A3B6D crankshaft.  The other weak point of the 4-cylinder Lycoming engines (and big Continentals, too), is case cracking. Find one, and you must tear down for repair, and usually another 20K major overhaul. This board is full of owners who, after sometimes as little as 400 since overhaul, find a cracked case and then the fun begins. I have a friend right now with a 400 SMOH IO-470 Continental in the shop right now. We elected to buy a factory OH engine from Lycoming in part, to get a fresh (maybe new) case to mitigate this risk.


Now regarding disuse, your results may vary wildly. Our plane flew 100 hours a year for ten years, then 45 and 30 hours respectively, the two years before we bought it. We then flew it 240 hours in 15 months only to have the camshaft lifters spall and ruin the entire engine.  Our story is not unique, or even uncommon.  The regular advice, and I wholly agree with, is buy a plane that flies regularly (2-3x a month minimum)  and ~100 hours per year. After 1500-1700 hours or ten years, price the engine as runout. Thats what we did too.


Our new engine from Lycoming will have roller lifters, so perhaps we can beat both these weak points. Aside from case cracking and this lifter/cam issue, I feel a Lycoming wll run forever. I used to fly behind two separate pairs of O-320 Lycomings with over 3500 SMOH on an Apache and a Travelair.  Ran great.  I flew a 2,300 SMOH flight school Warrior from Tulsa to  Wilmington, NC at full throttle and 2700 RPM. ~90% of rated power for 900 NM (11 hours) in one day.  Leaned it out and everything.  It used 1 quart of oil.


 

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Hi Pierre,

See my input below....

Quote: PapaPapa

Hi everyone,

 

so here come a pretty newbie question...

as i'm plannign to buy an M20J in the coming years, i already look at ads and all and i obviously have questions that pop from time to time.

Some i found answers to , others not so easily. Please note that being in EASA land maybe rules are different on some points ?

 

So about maintenance costs regarding limit times :

engine use TBO : 2000h then need OverHaul or replacement.

engin life span regardless of TBO :  ??  then needs ??

In most of Europe 12 years or 2000 Hrs whatever comes first (except Germany you can fly on condition if teh aircraft is not used for trainng etc...)

 

propeller use TBO : 1500 or 2000h or maybe no TBO (depending on brand and model) then needs OH or replacement

propeller life span regardless of TBO : ?? then needs ??

6 years or times you mention whatever comes first except Germany (to my knowledge) if the aircraft is for privat purposes only

Then, are there other TBOs or life spans that need to be monitored and need maintenance ? I'm thinking airframe ?

Airframe none, of course certain components need replacement as according to the maintenance shedule

Magneto's, etc..

These questions have arisen when i noticed some low use time M20J (since OH) but with long calendar periods, so i'm thinking even though the engine has 300h, as it's 10 y.o. it will need OH way before TBO ?

as I mentioned your taking risks here(it's 12 years or TBO in most EASA countries) a low time engine which hasn't flown reguraly is a box of pandora, my 0.5 eurocent. If you open the engine (due to some issue) you can't have back the core value from lycoming (see thread from Byron into the abyss....). This engine needs an overhaul anyway IMHO etc as discussed in several threads. You can take the risk by opening the engine for inspection but be ready for some surprises then....it may work out it may not....hope to see what the community here is saying on this..

 

hope this helps?

Luc

 

Thanks in advance for your help !

Pierre

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Quote: jetdriven

At which point, you are looking at a huge replacement bill, 4-6K for either item. We were told 8-10K for an IO-360-A3B6D crankshaft.  The other weak point of the 4-cylinder Lycoming engines (and big Continentals, too), is case cracking. Find one, and you must tear down for repair, and usually another 20K major overhaul. This board is full of owners who, after sometimes as little as 400 since overhaul, find a cracked case and then the fun begins. I have a friend right now with a 400 SMOH IO-470 Continental in the shop right now. We elected to buy a factory OH engine from Lycoming in part, to get a fresh (maybe new) case to mitigate this risk.

Now regarding disuse, your results may vary wildly. Our plane flew 100 hours a year for ten years, then 45 and 30 hours respectively, the two years before we bought it. We then flew it 240 hours in 15 months only to have the camshaft lifters spall and ruin the entire engine.  Our story is not unique, or even uncommon.  The regular advice, and I wholly agree with, is buy a plane that flies regularly (2-3x a month minimum)  and ~100 hours per year. After 1500-1700 hours or ten years, price the engine as runout. Thats what we did too.

Our new engine from Lycoming will have roller lifters, so perhaps we can beat both these weak points. Aside from case cracking and this lifter/cam issue, I feel a Lycoming wll run forever. I used to fly behind two separate pairs of O-320 Lycomings with over 3500 SMOH on an Apache and a Travelair.  Ran great.  I flew a 2,300 SMOH flight school Warrior from Tulsa to  Wilmington, NC at full throttle and 2700 RPM. ~90% of rated power for 900 NM (11 hours) in one day.  Leaned it out and everything.  It used 1 quart of oil.

 

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thanks for your valuable inputs (namely the 10 y.o. <=> worn out condition)


@Luc : today was really a "general" question about planes that don't fly so much and you sometime find on the market, not about AOGs for 2 to 4 years :-). Still i'm "happy" to read that i should expect surprises anyway, then i know where i stand and that i should keep a few AMUs ready...


@Byron : i read today about your misfortune and i'm confident all will turn out well, although it's just always "money issues" at the end of the day... right ? unfortunately it's not a limitless commodity :-)

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