It is dumb to go over 50hrs regularly, but it isn’t going to trash the engine for a little while.
There is probably little damage in doing so. What you should do is keep adding oil even when the engine doesn’t burn it (it will toss it overboard). This will keep the oil’s function intact. At some point you will notice that it gets more and more difficult to start the engine because of the lead on the spark plugs. From what my A&P told me, around 75h is when the spark plugs really need cleaning.
I change oil every 25h because it doesn’t cost much and it’s a nice and relaxing job which I have gotten rather good at (ca. 45min). My engine (1100h, turbo) does have quite a bit of blow-by but negligible oil burn. Spark plugs I do every 50h which is also a job I kind of like with sandblasting and using dental picks to clean them. My favorite job of course is cutting open the oil filter 
with G-regs it is 50hrs or 6 months whichever is earlier (as I understand it) i.e. even if you just fly 10hrs you have to tick the boxes after 6 months.
50hr checks are not mandatory under Part 91 (for SEPs, generally) but are required by the usual engine manufacturers.
In the US, manufacturers can’t require anything for Part 91 operations. They can void a warranty if their conditions aren’t met, but usually engine warranties are next to useless, but when an early failure occurs, the manufacturer will normally stand behind replacing it.
This is the bit I can never understand. For and aircraft used in flight training in the UK you have to have 50 hour checks. In the USA its 100 hours checks.
Now one method is must be wrong and as this has been the case for years there must be a huge amount of data which could be used to produce evidence to support one method or the other.
But we seem to pick the number of hours required for servicing based on historical or case based evidence.
Either the USA is wrong and they are putting people at risk or the UK is wrong and we are doing excessive servicing that make the UK flight training industry commercially less competitive.
This is the bit I can never understand. For and aircraft used in flight training in the UK you have to have 50 hour checks. In the USA its 100 hours checks.
I think the logic is simpler. For commercial use, you have to follow the manufacturer’s maintenance instructions and TBO. If your MM does not have a 50h check, you don’t have to do it under EASA in flight training. The 50h checks are rather profitable for the maintenance companies. They usually have a flat fee and do it in no time. As I mentioned before, one person 2-3h is enough for doing it thoroughly on my complex Cessna single. Cost of material about €80.
with G-regs it is 50hrs or 6 months whichever is earlier (as I understand it) i.e. even if you just fly 10hrs you have to tick the boxes after 6 months.
Yes – but isn’t there a concession for private use e.g. no renting, no training towards the initial award of a license or rating, no flights with CAA examiners? It used to be called Private CofA. It eliminated the 6m requirement, I believe. I am not up to date on this stuff however.
This will keep the oil’s function intact.
Only if you add a huge amount of oil. The oil you add will dilute the old oil and then perhaps 20% of the whole lot will go out of the breather, so you wasted 80% of the oil you added. Frankly, for the time it takes to drain the old treacle (great for lighting bonfires in the winter), you may as well do that.
the manufacturer will normally stand behind replacing it.
Don’t they ask for stuff like EDM700 data?
This is the bit I can never understand. For and aircraft used in flight training in the UK you have to have 50 hour checks. In the USA its 100 hours checks.
The US schools still do the 50hr oil changes / servicing.
The 100hr check is a specific-content service which is almost an Annual service. When I was doing the IR in Arizona, they had about seven 100hr checks between Annuals!
The FAA 100hr check is a similar thing to the G-reg 150hr check which is mandatory on all G-regs regardless of use and which is also almost an Annual.
I’d say that neither the FAA 100hr check nor the G-reg 150hr check has much engineering/safety basis, but I suppose the reasoning was that if the plane is doing 700hrs/year then perhaps it ought to be looked at more thoroughly every so often in between Annuals.
The G-reg 150hr check has the side effect of shafting syndicates (who often just bring forward the Annual), and high-time private owners (likewise), and totally shafting somebody who reaches the 150hr mark while on a long trip.
The 50h checks are rather profitable for the maintenance companies. They usually have a flat fee and do it in no time. As I mentioned before, one person 2-3h is enough for doing it thoroughly on my complex Cessna single. Cost of material about €80.
Exactly. £600+VAT plus consumables where I am based – for about 4 man-hours for the TB20. Doing these yourself is one of the biggest cost savings in aircraft ownership. You just aren’t allowed to do it if doing any school- or FTO-based training, CAA/school/FTO examiner checkrides, or charity flights, all of which require the last service beforehand to be the “full thing” (true even if doing e.g. a charity flight in an N-reg).
You just aren’t allowed to do it if doing any school- or FTO-based training, CAA/school/FTO examiner checkrides,
In Germany, there is a special provision for clubs that allows them to do 50/100h checks on their rental and training aircraft. Clubs do the bulk of PPL training over here. It requires club members involved in aircraft maintenance to attend a course at a maintenance company. One of the reasons why clubs can offer much lower rental rates than commercial outfits is that they can use free labor for maintenance.
A maintenance company I know tells customers their Lycoming needs the LW-16702 additive. So far so good. The way they do it is fill in straight Total oil at €12/l and then the Lycoming additive at €43 a bottle. You could also just fill in Aeroshell 15W50 for €7/l which already contains the Lycoming additive. To be fair, running a Part 145 profitably is not an easy job.
Not a 50 hrs check, but could have been. Our 50 hrs “orangutang” did an oil top-up on the Grob motorglider, just after this new year. I took the Grob on the first flight of the year when I for the first time ever had oil spray on the canopy. At first I did not realize it. The TAF had no rain, but as I took off, very light showers came in and reduced visibility somewhat, and my attention was on the weather and how much worse than forecast it was. Then I started wondering if it really used to be that bad for visibility with a little rain. Afher 5 minutes in the air, just as I was checking out of the CTR, I realized I had no forward vision. At the same time I saw a brown stripe running backwards on the lower part of the right side window, and it finally dawned on me that engine oil did not belong there, and I turned back. The engine ran fine, engine instruments were all normal. I made my first landing in a motorglider without any forward vision, interesting but uneventful fortunately. (Really only slightly worse that a normal landing in a Cub from the back seat, I guess.)
What had happened was that the helpful soul who had added oil had been distracted – a phone call? – and forgot to screw the oil plug back in before putting the cowling back on. On the G109B the cowling is a little cumbersome to remove and put back, but it is necessary when adding oil. The dipstick for checking oil is on the other side on the engine and has it little inspection door just like on other airplanes. It is impossible to check the top oil plug through the small door in the cowling, and the cowling is not removed during a routine preflight check. Not the best design. So I flew with the oil plug rattling around on the top of the engine, and a big open hole straight down to the engine. In 15 minutes of flying I lost about 0,5 litre, but it looked worse – what a mess. Even the front surfaces of the propeller were completely covered – I wonder about the airflow around there in flight.
I am sure I detected a slight smell of oil before take-off, and even a distinct metal-like sound at a certain RPM that could have been the oil plug dancing on top of the engine. I obviously did not act on that, and obviously I should have.
In Germany, there is a special provision for clubs that allows them to do 50/100h checks on their rental and training aircraft. Clubs do the bulk of PPL training over here. It requires club members involved in aircraft maintenance to attend a course at a maintenance company. One of the reasons why clubs can offer much lower rental rates than commercial outfits is that they can use free labor for maintenance
And this is another classic that I can never understand. Its either save or its unsave? And why isn’t this the same across europe EASA and all that.
It is safe of course or do you see German aircraft crashing more often than others and of those that crash, are the club managed overrepresented? EASA has nothing to do with safety, it’s a self-sufficient bureaucracy.
The clubs are the most influential group in GA in Germany. When EASA regulated the “cost sharing” and made it more restrictive than the previous German law (but still more permissible for most other member states), it was revised shortly thereafter because of massive intervention by Germany due to lobbying by the aeroclubs. The intervention was so massive that the German Federal Ministry of Transport told its subordinated agencies to ignore the EASA legislation which at the time was applicable law in Germany. I would never have thought that we’d see an officially sanctioned law infraction to protect GA.
Historically society here encourages people to engage in common activities through clubs. Those clubs are under special protection by authorities and there is a general notion that legislation harming the activities of clubs is bad legislation.
