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"Aircraft Quality" - Something To Think About.
We all know the old joke about the cost of hardware - put the word "marine" in front of a product description and you can double the price. Put the words "aircraft quality" in front and you can quadruple the price again.
I've lost count of the number of stories I've heard or been told about how certain bits of aircraft hardware are really vastly overpriced consumer items that have simply been "re-badged". For example, the internal door handle for a C172 is from a 1958 Rambler car or whatever and the oil filter for your engine is the same as the one from Home Depot that costs a quarter of the price, etc. etc. I'm sure we all have examples, and in many cases I'm sure its true. However, I'd like to add a little note of caution. We all know the standard retort to someone who tells us they have a new way of flying an aircraft; "Do you want to be your own test pilot?" I'd like to add another caution; "Do you want to be your own mechanical / electrical / aeronautical Engineer?"
There is a lot of stuff around that LOOKS like its aircraft quality or is "just as good as" aircraft quality. Quite a lot of it actually is....But here is the problem, how do YOU know? I submit, most of us don't know, but even then, if we may be talking about something that really doesn't matter to airworthiness anyway so who cares? Or so we think..........
For example, I know for a fact that the sheet metal of modern cars is made to tighter tolerances than that of an F18 fighter because I've messed around in the Airline and Aerospace industry a long time ago. I'm also pretty sure that the manufacturing technology in the auto industry is way ahead of the aviation industry in many respects. The trouble is that the quality dictum about "Fitness for purpose" means what it says. "Fitness for purpose" means one thing when you are talking about a something that merely annoys you if it fails in your car. It may be terrifying rather than just annoying when the same failure happens at Five thousand feet, in turbulence over forest with no landing place in sight.
Take ball bearings for example. Aircraft grade and automotive quality look the same. They may even have the same part number and of course look identical - to you., the reality is that the finished bearings got graded - the best went to the aviation industry, the average to the auto industry and the rejects went to Home Depot for the schmucks to buy. To put it another way, do I buy an aircraft grade switch or just something that looks like it will do the job? Do I buy a converted automotive engine or a purpose built aircraft engine? They both do the same job don't they? You find out.
Replies to This Discussion
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Permalink Reply by Jan Eggenfellner on
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"Do I buy a converted automotive engine or a purpose built aircraft engine? They both do the same job don't they? You find out."
So, what is an "Aircraft Engine" for our sport aircraft?
And what is a "Converted car engine?
How many parts has to be made from scratch in a small shop for it to be an "Aircraft engine"?
If I make my Cylinders for my "Aircraft" engine, but I buy and modify my crank, does that qualify?
Can I use automotive pistons and just cast my Aircraft oil pan?
If I use coil ignition from a lawnmower, but throw in dual for redundancy, is it aircraft?
If I intended it to be an "Aircraft" engine from the start? Is it then an "Aircraft" engine?
Can I use snowmobile carburetors? Automotive plugs? Metric commercial grade hardware? Automotive oil? How about motorcycle push-pull cables and springs on my throttle? Is that "Aircraft"
I am confused
Jan
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Permalink Reply by Geoff Klestadt on
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Traceability and testing to approved aviation standards that guarantee that the parts will perform as advertised in an aviation environment are what you pay for. I tend to treat aircraft and their components with a certain amount of reverence because as an engineer, I'm fascinated why certain stuff is designed "This way" and not "That way", which looks much easier......... I think of all the people who must have paid with their lives over the years before designers learned how to make something that did what it was supposed to do reliably. I'm therefore a little cautious about adopting something "new" and "better" and so is the aviation industry.
For example, the industry still hasn't adopted Aluminium / Magnesium alloys in many aircraft structures, despite them having better strength to weight ratios, for the simple reason that those old conservatives can't forget that magnesium burns, even though today that is a remote possibility.
As for an assemblage of automotive componentry working in an Aviation environment, I hope it does, for you and your customers sake. I fail to see why a Honda core wouldn't perform well, but I guess that we won't know for sure if it can reliably stand an aviation duty cycle for a Thousand hours or more until it does will we? The same goes for the additional components and accessories.
I think it is terrific that Continental and Lycoming are getting competition, because it improves the breed which is good for all of us.
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Permalink Reply by Brian Fitzpatrick on
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Hi Steve Weston:
It really does go both ways. Look at the BMW car logo. As you know it is circular. Divided into two white triangles and two blue triangles joined at the apex.
This logo represents a blurring white propellor against a blue sky.
BMW was one of, if not the first aircraft engine manufacturer to supply engines for fighter planes back in World War One. The engine was a derivative of a BMW auto engine.
It was water cooled and very successful and I believe they made engines for the Luftwaffe during the second period of unpleasantness as well. If any one has comments I would be pleased to hear them as my knowledge is limited.
I would be pleased to make that logo fly again but cant seem to find a BMW car engine light enough for my 750. Brian
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Permalink Reply by Bob Pustell on
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There are several BMW motorcycle engine powered airplanes flying. Same logo. Great engines. They make enough power to fly a two seat plane.
I saw one installation years ago where the builder used the motorcyle transmission as his reduction drive. At the time I saw it he had all the gears in the tranny and was experimenting with different reduction ratios by the simple expedient of shifting the gears in the tranny. Once he found the gear that worked best, he planned to remove the surplus parts to save weight and just have the gearset he needed. I never saw that rig again, do not know how reliable and effective it turned out to be.
For sure, many homebuilts have flown on motorcyle engine power, and many are to this day.
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Permalink Reply by Paul Bonasera on
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Jan,
Glad to see more choise in the engine world.
Thanks Paul
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So if I have a Ford voltage regulator on my cesna with out the FAA/PMA sticker on it It's not as good? And all those people flying behind (or in front of) 503's , 582's ' 912's should land them now and go out and buy a Wright engine?
Did you notice that the Wright bro's didn't have one part on there plane that was FAA/PMA and neather one had had a check ride in the last two years. If you open the door on most of our aircraft you will find a 2" high sticker that tells you we are ALL EXPERIMENTAL Aircraft Pilots and that you should never treat them as anything else. I have seen a Lycoming IO-360 put a rod thru the case with 5 hrs on it since NEW. A O-320 blow the head off the Cylinder with 260 hrs. Since NEW. I also own a Buick with 348,000 miles on it. My point is Things happen and we dont have a lot of control over them some call it fate.
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Permalink Reply by Normand Lambert on
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Hi Guys,
I never get bored with these discussions...Especially with engines. Those Lyco and Cont which were designed back in the 50's still going strong. This old technology maybe sort of reliable but today a 4 cylinder car engine can do better, rev faster and last longer. Also, the ignition and all other electronic parts are better designed and more efficient. By the way, Bombardier came out of the Skidoo business with their 5xx, 532, 58X, 60X and 91X series engines for aircraft use doesn't that tell you something ??? Never saw a Continental or Lycoming engine in a car ?
I didn't think so. They could never endure the kind of punishement we put our cars, Skidoos, motorcycle thru everyday.
Just my tought on this.
Norm
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Permalink Reply by John Austin on
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An interesting discussion ... case in point - I have a '99 Cessna Stationair/206. It was supposed to have a new Lycoming engine, an IO-580, but apparently it failed a "torture test" and Cessna decided to go with the " 'ole reliable", an IO-540, an engine with a gazillion hours of history.
Guess what? The IO-540 in my plane had a crankshaft AD - I had to change out the crank at about $11,000+ (and this was a discounted price from Lycoming). Lycoming had changed the metal in the crank and screwed up! A class-action suit went nowhere and we were s*&$#$d!
So, a certificated engine is no guarantee of reliability!
Regards,
John
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I feel your pain.....
Yes, certificated engine manufacturers make mistakes, the difference is that at least once they find the mistake they can accurately determine which engines are affected.
What irritates me is the know - it - alls at the bar who confidently explain to all who will listen about how Lycoming and Continental engines are dinosaurs, and that modern automotive technology, electronic ignition, variable valve timing, overhead cams, electronic fuel injection makes them obsolete, are far more efficient, etc., etc. We have all heard it more than once.
Like all good arguments, there is a grain of truth in it. What they forget of course is the duty cycle of the engine, the aviation environment, the financial environment, the regulatory environment and the cost of failure. When you take all of those factors into account, a Lycosaurus makes a lot of sense.
I'm all for progress, technology and competition, but sometimes simplicity is trumps.
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"I'm all for progress, technology and competition, but sometimes simplicity is trumps."
Nothing like an inline 4. Can't get much simpler. Ever seen an exhaust system
on an opposed 4 cylinder engine? How about a 6 of the same power? How about a
Viking exhaust?How many EGT probes and wires to monitor a 6 cylinder air
cooled? 6
How many for the Viking? 0
How many CHT probes to know what is going on for the air cooled 6? 6
How many on the Viking, to have a complete picture? 1 (coolant temp)
How many exhaust gaskets to replace on the 6cyl air cooled at 500 hr inspection?
6
How about the Viking? 1
How about leaky Valve cover gaskets? 6 and 1? Yes, that is right.The Viking is a simple powerful engine
Jan
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Permalink Reply by Tim Treat on
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How many geared reduction drives on a 6 cyl air cooled - 0
How much coolant in an air cooled - 0
How many batteries are REQUIRED to start and run a 6 cyl air cooled - 0
How many revs on a 6 cyl air cooled - 1/2 the Viking
How many spark plugs in the viking - 4 6 cyl air cooled - 12
How many hours have been logged on a viking engine - ???
I'm restating my personal engine criteria using your sales scoring system. I still like my decision.
You crack me up. Are you capable of discussing your product without putting everyone else down? We are not idiots. Lay out your features and benefits and let us decide. I still can't figure out if your engine is a Honda or not. Your info is conflicting. Is the core engine new?
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My initial reply was just to say the Viking layout is very simple. The most popular light aircraft engine, EVER .. has a reduction drive, some liquid cooling to prevent cylinder hot spots, needs a battery to start, turns 5800 for takeoff, has a good reputation but is a little pricy. The Viking has this engines attributes but simplified and overall stronger construction. Don't be afraid to admit that an inline 4 is as simple as it gets. I am happy the propeller loads are not on the crankshaft, that the viking does not have 12 high tension sparkplug wires (it has 0), that only 4, not 12 plugs has to be inspected, etc. Good and bad with every design - the discussion was about simplicity - The Vikings inline 4 design will win that part of the design contest every time.
Jan
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