Is this a dumb question?

[Geofa 108]

It isn't really the edge of disaster. Many aircraft that fly today are older in age-my Debonair was a 1962 model. It was designed at a simpler time when there were just a few avionics that didn't draw much power and originally had a generator instead of an alternator. When aircraft started to get more avionics and equipment-the generator on this plane was converted to a 40 amp alternator(has to have Faa approval first)-but additional avionics and additional equipement like anticollision lights kept being added to the aircraft. Having everything turned on including the pitot and landing lights-(two of the biggest draws) could overtax the alternator. If you needed both on you usually turned something else you didn't absolutely need off, if the alternator wasn't keeping up-which sometimes happened and sometimes didn't. I finally converted it to a 60 amp alternator and was able to have everything on-of course that cost a lot of money-and some aircraft you can't get approval to do this. A company has to get special approval from the Faa to modify something like this-so even if you want to put a bigger alternator on it may not even be an option for the aircraft you own.Now flying a Baron I have two alternators. Still-when you want to test if the alternators are working you turn one of the alternators off- then heavy drains like the pitot heat and landing lights on-the pitot and landing light will take a pretty big draw on the needle.http://mywebpages.comcast.net/geofa/pages/rxp-pilot.jpg

[LAdamson 240]

And, as the alternator has to create a higher amperage to satisfy the load, it's also taking some of the available "prop" horsepower from the engine to do it. It's just like turning on the air conditioner in a car, and feeling the loss of power.Happily, dealing with "experimental aircraft", I installed a 60 amp alternator on the Lycoming because of the pitot heat. And I may never use it; it just looked cool. But when I bought it, it was around $200. Now it's closer to $1900.00! Must be one of those "liability" things! :-hah L.Adamson

[Geofa 108]

Sounds like a bargain-the one I put on the Deb was closer to 3 grand installed...http://mywebpages.comcast.net/geofa/pages/rxp-pilot.jpg

[Manny 1,293]

You have to realize...a cheap Hundai automobile has more sophisticated technology than a $300,000 GA aircraft. Economy of scale has to do with it I suspect. Even Carborated engines are used in many of the GA aircrafts.:)Manny

[FlyingsCool 3]

Diesel power is very popular choice now in GA singles in Europe, and several companies are working on STC's for the U.S. market as well.Thomas[a href=http://www.flyingscool.com] http://www.flyingscool.com/images/Signature.jpg [/a]I like using VC's :-)N15802 KASH '73 Piper Cherokee Challenger 180

[FlyingsCool 3]

It has more to do with those reasons mentioned above. It it was easy to certify, they would just take the systems developed for cars.Thomas[a href=http://www.flyingscool.com] http://www.flyingscool.com/images/Signature.jpg [/a]I like using VC's :-)N15802 KASH '73 Piper Cherokee Challenger 180

[LAdamson 240]

>It has more to do with those reasons mentioned above. It it>was easy to certify, they would just take the systems>developed for cars.>Within the homebuilt/kitplane/experimental market, where you're free to use engines of choice; the "argument" and preference's between certified aircraft engines and automobile derivatives goes on and on.The majority still prefers the air cooled Lycomings and Continentals.Auto engines require radiators along with anti-freeze that need to be shoehorned into a cowl without adding too much additional drag. They also need prop reduction units, with either belts or gears, to get the 5500-6500 rpms down to usable prop speeds of around 2700-3000 rpm. This adds more weight and another possible failure point.Then there is the electrical systems that depend on an operating alternator and battery, instead of "magneto's" should the main electrical system go off line. This requires additional redunency and weight, in one form or another.The "airplane" engine, also has a hollow crankshaft on the forward section for pressurized oil which operates the constant speed propeller. Using an auto engine requires an electric prop or just a fixed pitch.As to pricing, the certified aircraft engines are a lot more than the base price of a comparable horsepower modern auto engine. But by the time all the accessories are installed for the firewall forward, then the prices are rather comparable.These airplane engines are still somewhat 1930's technology, but in many ways, the simplicity and "weight" still beats the alternatives. Fuel injection is available and widely used, but carburetors still have their own advantages. Electric ignition systems may also replace at least one of the magneto's, while the other is still a backup.L.Adamson

[Guest X15]

I'll tell you OP, they have it all wrong. It isn't because airplane designers are dumb (they are very clever) it is because pilots are dumb. You see if the designers made it all automated then student pilots (like myself) would never have to consider icing conditions and aeroplanes would be forever falling out of the sky. That's the real reason. (excuse me while I duck under my desk)