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On Tue, 19 Feb 2008 17:15:11 +0000, David Lesher wrote:
Well, if "old" Diesels made sense for GA use, you'd a thunk there would be lots by now. There don't seem to be. My understanding is that this has, until recently, been a weight issue. [...] There are real issues with starting over, and ignoring everything other But there's a great deal of space between retasking and "starting over, and ignoring everything other people found out The Hard Way". So this is something of a strawman argument. [...] There are significant advantages to engines that run closed-loop, and FADEC control systems add others. Yes, it's best to have zero single points of failure in any design, be it a Bonanza or a highway bridge, [or flywheels] but that's not always possible. This appears to me to be another strawman. Sure, zero SPOF is not always possible. But how does that impact the goal of minimizing the SPOF? Your later comments about granite cumulus would appear to be of the same sort. Hyperbole, perhaps? [...] (The alternative, by the way, is where GA is now -- 1950's technology holds forth; outside of the avionics, and it run on 1960-design alternators.) This might also be explained by the size of the market. Also, don't ignore the "pause" imposed by the liability issue. Now that small GA is "moving again" we are seeing innovation. Avionics has been getting a lot of attention over the past few years thanks to advancements in electronics, and it appears that we're now seeing the result of evolution in the engine market. - Andrew |
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Andrew Gideon writes:
Well, if "old" Diesels made sense for GA use, you'd a thunk there would be lots by now. There don't seem to be. My understanding is that this has, until recently, been a weight issue. Note that over the last ~30 years, cars too have come under intense scrutiny over weight, and where to (and not to...) save. It includes things such as making the brake cylinder{s} from aluminum vice steel, reducing the capacity of the automatic transmission case/sump to use less ATF, etc. and many smaller gains. All those ounces add up. There are significant advantages to engines that run closed-loop, and FADEC control systems add others. Yes, it's best to have zero single points of failure in any design, be it a Bonanza or a highway bridge, [or flywheels] but that's not always possible. This appears to me to be another strawman. Sure, zero SPOF is not always possible. But how does that impact the goal of minimizing the SPOF? Your later comments about granite cumulus would appear to be of the same sort. Hyperbole, perhaps? Call them what you want. Zero SPOF is almost never possible. The question is, what do you gain, and how do you mitigate the new risk? That twin with the dead battery is a good example; it was bad engineering to depend on the one main battery for the FADEC's, but with an added gel-cell for them alone, that flaw is 99% gone. [You need some automagic battery test as part of startup.] (The alternative, by the way, is where GA is now -- 1950's technology holds forth; outside of the avionics, and it run on 1960-design alternators.) This might also be explained by the size of the market. Also, don't ignore the "pause" imposed by the liability issue. Now that small GA is "moving again" we are seeing innovation. You think it's moving? I'll let others speak their mind {Jay, Donnie etc.}, but from outside, it looks to me like it's reaching stall speed. GA {in the US} faces large fuel cost increases, an aging fleet, airport losses to developers, and an overall grim economy. And, sooner than you think, I bet leaded gas will vanish. Then what? Does AOPA etc. try to estimate the # of GA hours flown per year? I can see two ways to swag same: ATC data and total gallons of 100 Octane sold. Both have flaws but it might be interesting to see a 10-20 year trend. And I'm not one to discount the coffin corner of low volumes plus regulatory overhead. But what I observe is not a pause but a fergett-it by new vendors coming from such. YMMV. -- A host is a host from coast to & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433 |
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