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List of reasons to learn/keep flying privately?

As I say, with time and more money, I'm sure I'll stop caring. But does anyone honestly buy a standard aircraft engine and think "Wow, that's a fair price!"

No, what some of us do is buy 40-60 year old aircraft engines, field overhaul them to like new condition with parts from multiple, competing suppliers, and pay a fraction of the price of a new engine. Then after a long time in service (I may actually be dead before its required ;-) we do it again...

There is a reason why things are the way they are with aircraft engines and it's not mass irrationality :-)

A bit back we bought a brand new Vedeneyev M14P for a Yak I had a share in....cost about £10K IIRC.

Thanks Vince. Built to the nearest half brick, the Russian kit is a good example of what I was talking about. Although part of me abhors the idea (oil burn rate only just less than fuel burn rate!), there's a great part of me that would love to get something like a Yak18T. A lot of aircraft for your money and just having something a bit different.

No, what some of us do is buy 40-60 year old aircraft engines, field overhaul them to like new condition with parts from multiple, competing suppliers

Silvaire, field overhaul in the sense you have all the engineering kit in your garage/hangar, or you have a good local firm you can sub the work out to. What sort of engines have you worked on? Does anyone know if we have the equivalent of aero motor factors in the UK? (a place where you can buy virtually any part for your car (engine))

The topic of car engines comes up often. I don't think there is any car engine which would make the required ~100% power for the duration of the climb (say half an hour, if turbocharged) and then cruise at 65%-75% for several hours, and still have a fair chance of making 2000hrs.

Notwithstanding the different modes of operation of aero vs car engines, the idea that car engines spontaneously self destruct if they are used at WOT for more than 10 seconds is one of those enduring myths. At one time, around the time Lycoming first started making their engines, I'm sure it was true. Car engines used to be very cr*p. Now car engines are generally very, very good and are the most reliable component of the car. Car manufacturers and oil manufacturers devote a great deal of resources to endurance testing.

As a flavour of what car engines can do, one of Castrol's endurance tests involves running a car for up to 6 days WOT, and then the test only stops because the oil starts to breakdown. There's an interesting torture test that Ford have subjected one of their new engines to on Youtube. Very interesting.

I have no idea whether the lack of car engines being applied with success in aero applications is down to half baked attempts, or due to a fundamental design problem. The Centurion engines are approx twice as reliable as conventional aero piston engines in terms of in flight shutdowns according to the FAA...so far!

Silvaire, field overhaul in the sense you have all the engineering kit in your garage/hangar, or you have a good local firm you can sub the work out to. What sort of engines have you worked on? Does anyone know if we have the equivalent of aero motor factors in the UK? (a place where you can buy virtually any part for your car (engine))

I overhauled an A65 Continental a few years ago (taking baby steps, starting with an engine that cost me a couple of thousand $) and have taken part in similar work on an O-200, an O-360 Lycoming, an AEIO-550 (mainly I watched), and most recently an old and obsolete O-340. Most of them were for experimentals.

Where I'm based, most privately owned aircraft are based in their own hangar and some of the hangars are quite elaborate. Intermixed with those hangars are businesses that have more capability. Further afield, engine components get sent to repair stations and (hopefully!) come back reworked and 'yellow tagged'. New parts come in a few days via UPS. Through some combination of all that, with the assistance of others, and generally with the supervision of an appropriately qualified mechanic, the work can get done.

These are simple engines, and if you have access to a culture that has been maintaining them for decades, it is certainly helpful.

Yes, there is a aircraft parts supply shop nearby - I call it the 7-11 (convenience store) because the prices are relatively high but you can get a lot of stuff you might need in ten minutes. They're open until lunch time on Saturdays...

What can be easily forgotten, over here in Europe where everything has to be buried under 1" of paper first, is that the old US engines are routinely overhauled several times.

It's a huge business in the USA.

The tendency with the new engines (Thielert and Austro) is to throw all or most of it away, because at 1500hrs or whatever too much of it is knackered to make it worth reusing. Also there is not enough service history in that product to be sure how effective standard NDT is, so throwing stuff away is the "safe" option.

Also we have too many scenarios where there is a 12 year life imposed on an engine, which has no engineering basis.

Administrator
Shoreham EGKA, United Kingdom

Re overhauling and NDT etc experience, here's a story I found interesting about the experimental (and I stress that the work is non-certified) O-340 Lycoming that a guy I know is building up for an old school (but 200 mph) homebuilt: the crankshaft machine shop (an FAA certified repair station) took his rare and very difficult to replace O-340 crankshaft and threw it out of the machine, bending it 1/8 inch (3-mm) or so. They then sent it back to him red tagged, saying it was bent upon receipt. The question "why did you do so much work on it then?" had no positive effect... The technical solution was to call around and ask 'everybody who is anybody in aircraft crankshafts' what to do. Then having done that, the crank was formed back to its original shape amd made useable!

Where did the 'outside of the box' experience come from to know this will be OK? Among other places, a Lycoming engine builder who buys red tagged parts, reworks them into air boat engines, and sells them (with a warranty) at a rate significantly higher than most aircraft engine shops. He apparently has a much bigger and more sophisticated machine shop too...

The O-340 is an O-320 with a unique crankshaft and a few other changes that makes 170 HP, or maybe 180 HP when smoothed over a bit. Lighter than an 0-360, and almost valueless as a core.

As a flavour of what car engines can do, one of Castrol's endurance tests involves running a car for up to 6 days WOT

What would be more interesting, is to know what would happen if they ran lots of cars for 6 days WOT. A failure rate of 1%, which might not seem unreasonable in cars, would be unacceptable in aircraft. Also, I think I'm correct in saying that wide-open-throttle doesn't necessarily equate to full-power - depending on RPM etc...

To be fair, many aircraft engines can't be operated at 100% power, primarily due to cooling issues.

I'm not generally a luddite, but the more I learn about aircraft engines, the more I like their relative simplicity. And it's certainly true that a lot of manufacturers (e.g. Porsche) have come to grief when venturing into aircraft engines, and that many of the homebuilt conversions haven't proved terribly reliable.

Perhaps we'll get some new, reliable options now that smaller engines are being developed for military drones. I'm sceptical that they'll be any cheaper though.

The thing I always noticed when watching stuff on TV about rally cars is that they were changing the engines every few days.

Maybe things have improved but I can't believe it is the norm, because catastrophic engine failures (as opposed to loss of coolant, etc) in car engines are extremely rare and always have been. Making car engines stronger is statistically completely pointless.

OTOH I don't think Thielert (or Porsche) were getting catastrophic (mechanical) failures. Thielert were having loads of peripheral stuff going wrong; stuff with the cooling system, stuff with the FADEC, etc. And of course the gearboxes and clutches, which were not present on the car versions.

I think we are living off the huge base of statistical data and field experience gained on the old engines, most of it dating from the heyday of GA from the 1960s and around there, whereas today new airframe sales are much lower and if you take out those that use the old engines it leaves a very low level of new engine sales. How many DA40 and DA42 diesels have been sold?

Also there is much more "community expertise" with the old engines, mainly from the USA where stuff is a lot more open. The Diamonds have been sold mainly in Europe, with servicing limited to authorised dealers, and with (IMHO) most of the diesels going to flying schools. With so much of the product covered by a warranty of some sort, operated under an authorised dealer, and operated by businesses who have an huge incentive to play down downtime, you end up with an environment in which very little experience leaks out.

If you walk up Lycoming at an exhibition and ask about reliability, and they tell you their engines are fantastic, you can verify this against a load of other sources. If you walk up to Thielert at an exhibition and ask about reliability, and they tell you their engines are fantastic, you cannot verify this unless you happen to personally know somebody who works inside an FTO using them or inside a Diamond dealer.

I know from personal experience that if you wash your dirty laundry publicly, you get cut off from support, so you don't do that until all possible warranties have ended and you have the ongoing maintenance well organised.

What this adds up to is that when flying behind a Lyco IO540 (or whatever) you know there are certain weak points, so you do oil analysis, etc. But the engines are extremely unlikely to just stop (unless assembled by some cowboy, and that too is a part of the "knowledge" process). Whereas the Thielert diesels were fairly likely to "just stop", due to external issues.

Administrator
Shoreham EGKA, United Kingdom

The thing I always noticed when watching stuff on TV about rally cars is that they were changing the engines every few days

When was it you were watching? Back in the Group B golden era of rallying (early 80's), the cars were typically putting out 600 bhp from a 1.8litre engine (although some engines were run with up to 5 bar of boost and 1000 bhp). Not surprisingly, those engines, with the lower tech oils and materials of the day had a shortened shelf life.

In general, it's not the engine that fails. It's suspension and gearbox that fails, usually because the driver has pranged the car, and depending on the design of the car (ie one that uses the engine/gearbox as a stressed member) then engine comes out. If the engine has failed, it's usually because a rock has punched a hole in the radiator or sump as a result of flying debris (or a prang) and the driver has driven the last half of a stage with no oil/coolant, knowing that if he can get the car back to service, he can swap a new engine back in

Also, I think I'm correct in saying that wide-open-throttle doesn't necessarily equate to full-power - depending on RPM etc..

You may of may not be at full power, but you'll be stressing the bottom end of the engine to the maximum extent possible. It was quite interesting on the Ford test, where they cooled the engine to -40 degrees and thrashed it from cold. Repeatedly. Over a 24 hour period. Love to have seen how a Lyc/Conti would have coped.

There's no doubt that the legacy engines available today are fit for purpose (if arguably sub optimal). My concern is where there is a mindset of zero innovation. Things that don't adapt and evolve invariably die. For example, if Avgas were banned or stringent emissions limits were imposed at fairly short notice 99% of GA would be screwed. After sitting on it's laurels for the best part of 50 years, there's no way GA would be able to adapt quick enough. Constant innovation enables you to adapt - ability to adapt gives you a Plan B. That's a good thing

if Avgas were banned or stringent emissions limits were imposed at fairly short notice 99% of GA would be screwed.

Yes, but equally I don't think Avgas will be banned so quickly or simply.

The refineries can make it easily, and they make plenty of money on it, as do airports that currently carry it.

In the "free world" you tend to not get regs introduced which have a totally crazy effect on so many people and businesses.

Administrator
Shoreham EGKA, United Kingdom

If Avgas were banned, a fairly high proportion of aircraft would still be able to run on UL91 or Mogas. If people were willing to accept a modest performance hit, then there is also quite a lot you can do about emissions and noise.

I think it's overstating the case a bit to say that innovation is dead in aircraft engines. Rotax, Jabiru, Porsche, Thielert have all introduced new engines within the past decade or two. There are lots of small companies making parts, conversion kits or upgrades for existing engines. Homebuilders have converted many car engines for aircraft use, with varying degrees of success. But a lot of these companies have fallen by the wayside and whilst a Rotax has a pleasantly lower fuel consumption than a Lycoming, neither the difference in price or consumption is compelling.

How much innovation has there been in biro manufacture over the past 30 years? I suspect there has been some, because they leak less than they used to and because there are a few designs of ballpoint pen that I don't remember from when I was little (e.g. fineliners). However, a biro in 2012 is essentially similar to a biro from 1982. I use one every day. I don't see any real need to change it, and whilst I'm aware that there are more advanced pens on the market, biros work fine for my needs and are cheap enough that I don't get upset when I inevitably lose them or they get borrowed. Perhaps in a decade or so, computers will make inroads into my workplace and I will find that I don't need to use a biro any more, but until then I don't see any need for innovation for innovation's sake.

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