Auto conversion ideas

[Dan Thomas]

that's a lot of words to be wrong. Tell me, how many certificated AC have RPM range limits? Why is that? The exact same reason.

OK.> So tell me why these tachometers have yellow or red markings within their RPM limits?




The first is from a Piper Arrow. The PA-28 series had such tachs, depending on engine/propeller combinations. That prop would flex dangerously at certain resonant RPMs, hence the red band to stay out of. And that's a direct-drive engine.

The second is from a Cessna 152, which had the infamous gullwing prop on the O-235. A yellow band to avoid where possible.

There are many such aircraft; some direct-drive, and of course some geared. There is a lot of stuff in this business you just don't know.

THose springs are the exact same thing as belt in a reduction drive.

They'll act the same as a V-belt, which will allow slippage. But the cog-belt (timing-belt) drives common now do not absorb TV. That Subaru with the RAF redrive had such a belt, and TV was a serious issue in it. Those belts are nearly as rigid as steel, in tension.

I will 100% agree that the ability of the person putting the entire system together is vital. But again, for every car motor that stops turning because of X (and no, not vibration) there is a certified motor stopping for just as stupid/preventable a reason.

Not true at all. Electrical failures are common in both cars and airplanes. But while an electrical failure in a car shuts down all the ignition and fuel injection, the airplane keeps running with its magnetos. Aircraft engines that quit do so for one of two reasons: (A) lack of maintenance, and (B) lack of pilot knowledge and skill. Running out of fuel, for instance, will stop any IC engine. Running the engine until the oil is all used up will do it too. Factors like this are NOT the aircraft manufacturer's fault.

There is no magical math in 80 year old tractor motor used in airplanes. I may not be nuanced in my statement, but it is accurate.

There is a lot of math in any engine. As far a "magical math," are you referring to math you don't understand? The math involved in torsional vibration, for instance, is engineer-level stuff. Six years university stuff. It's not high-school math.

The wise man know this, here:



He also knows that both the green and red slices are really generous. The smartest of us know nearly nothing.

 

[hindsight2020]

....or (c) materials fatigue. Unless you think not prophilactically tearing down a lycosaurus to replace case thrubolts and studs after every flight falls under (a) lack of maintenance. Heck, the irony being that such a logistics- and economics- non-starter of an action would actually give rise to (d) maintenance-induced failure. I'd love to hear the gymnastics of trying to shoehorn (d) as somehow still under (a).