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#11
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Evan,
I don't want to drag this out, I think some good points ahve been made -- however, I don't see why fiberglass airframe construction is going to be less labor-intensive. There is almost zero opportunity for automation in fiberglass construction, unless you go to specialized processes and tooling that are probably out of reach for a small firm. Even Cirrus and Adam do a lot of their layups by hand -- granted using pre-pregs. Now look at a simple little plane like the Zenith 601. They used to build one of these in a week at Oshkosh, using volunteers from the crowd. It uses pull-type rivets rather than bucked, so the structure can be assembled quite quickly. I think the total time to get to the flying plane was about 300 man hours. And I don't think the Zenith kit parts are as automated as they could be -- for instance I don't the they are fully precut and pre-punched etc. like the Van's kits. My point is that if you purpose-designed a small aluminum airplane for quick construction and automated the sheet-metal stamping part of the process, you could make that airplane very cost-effectively. Perhaps a fiberglass approach could work just as well, but I think more ingenuity would be required. Regards, Gordon. "Evan Carew" wrote in message .. . Gordon, Unfortunately, I have to disagree with you on your analysis of aluminum use in commercially built LSA aircraft structures. While it is true that the aluminum materials costs for an aircraft are lower, the labor costs (which I have already shown to be the largest cost in building any plane) are much higher, thus making it a poor choice if you are trying to build such airplanes for a profit. On the other hand, if you are trying to sell kit LSA airframes, then the builder assumes the labor costs, thus making a comparable kit seem less expensive. |
#12
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On Sun, 18 Sep 2005 23:37:30 -0400, "Gordon Arnaut"
wrote: Evan, I don't want to drag this out, I think some good points ahve been made -- however, I don't see why fiberglass airframe construction is going to be less labor-intensive. Once you have the moulds constructed, fiberglass lends itself well to making large compound structures as one piece. There is almost zero opportunity for automation in fiberglass construction, That depends on your thinking. Fiberglass composite also lends itself well to putting pieces together. unless you go to specialized processes and tooling that are probably out of reach for a small firm. Even Cirrus and Adam do a lot of their layups by hand -- granted using pre-pregs. Now look at a simple little plane like the Zenith 601. They used to build one of these in a week at Oshkosh, using volunteers from the crowd. It uses pull-type rivets rather than bucked, so the structure can be assembled quite quickly. I think the total time to get to the flying plane was about 300 man hours. And I don't think the Zenith kit parts are as automated as they could be -- for instance I don't the they are fully precut and pre-punched etc. like the Van's kits. My point is that if you purpose-designed a small aluminum airplane for quick construction and automated the sheet-metal stamping part of the process, you could make that airplane very cost-effectively. Perhaps a fiberglass approach could work just as well, but I think more ingenuity would be required. It would and it would. However, in the case of the sport plane specifications, the plane could be constructed of shells that could be fastened together. They could be composite shells, with the joggle and two aluminum strips where they would be pop riveted together with cherry max rivets. After all they do not under go any where near the stress of a Cirrus, Lancair, or Glasair III. Staying within those specs makes both the metal and composite structures much more simple. OTOH you still have all the insurance costs. If and I emphasize the IF the market were there to justify true mass production then airframes, engines and basic avionics could be produced at considerably less. If you could sell even 20,000 small displacement engines like the Jabaru they'd become *relatively* less expensive compared to now. Let's face it, even at Cessna's best year, that was a specialized market and peanuts compared to the automobile. However, first you have to have the market. You aren't going to do a lot of high profile advertising for a nitch market that may develop. Once the potential market is there the advertising can increase, and production will follow. It's much like the chicken or the egg. The market has to develop slowly. The faster it develops the more sensitive it is to upsets. However, I seriously doubt that we will ever see more than about three times the number of planes currently flying. Beyond that we'd need a complete now traffic system even if most of it is local. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com Regards, Gordon. "Evan Carew" wrote in message . .. Gordon, Unfortunately, I have to disagree with you on your analysis of aluminum use in commercially built LSA aircraft structures. While it is true that the aluminum materials costs for an aircraft are lower, the labor costs (which I have already shown to be the largest cost in building any plane) are much higher, thus making it a poor choice if you are trying to build such airplanes for a profit. On the other hand, if you are trying to sell kit LSA airframes, then the builder assumes the labor costs, thus making a comparable kit seem less expensive. |
#13
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On Mon, 19 Sep 2005 03:47:38 -0400, Roger
wrote: On Sun, 18 Sep 2005 23:37:30 -0400, "Gordon Arnaut" wrote: Evan, I don't want to drag this out, I think some good points ahve been made -- however, I don't see why fiberglass airframe construction is going to be less labor-intensive. Once you have the moulds constructed, fiberglass lends itself well to making large compound structures as one piece. There is almost zero opportunity for automation in fiberglass construction, That depends on your thinking. Fiberglass composite also lends itself well to putting pieces together. I dunno, Roger. I've been both to the Glastar factory and the Vans factory. At Vans, a guy feeds a big piece of aluminum into a big CNC machine and whango-whango-whango out comes a big pile of RV parts. But then I go see the Glastar's fiberglass fuselage made, and its spray the release agent onto the mold, then the gelcoat, then cut pieces of fiberglass and lay them into the mold, then squeegee on some resin, then apply the foam, then apply another layer of fiberglass and more resin, etc. etc., lather, rinse, repeat, then let the assembly tie up your every expensive mold while the resin cures. Looked to me that manufacturing aircraft parts in fiberglass is a *lot* more effort...though I allow that less-skilled workers can probably be used. Ron Wanttaja P.S. Wanna hear something *really* scary? My spell checker passed "whango-whango-whango" but hiccuped on "gelcoat." |
#14
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Ron,
That's a good comparison. A Glasair or Lancair kit costs about double what a Van's kit costs and it still takes about the same build time to complete. In fact even the Van's quick-build costs less than a Glasair slow-build and you get probably less than half the build time. And what if the Van's kit were designed to be built with pulled rivets? This would cut build time dramatically and that slow-build kit could be built in about the same time it takes to build one of the composite fast-build kits that cost three times as much. Look at the Zenith 601, and compare its price to some of the sportplane composite kits. The composte kits are usually twice as much money. The conclusion has to be that composites are more expensive because it costs more to make them. No question about it, composite construction involves lots of hands-on labor. Also composite materials are expensive compared to aluminum. So if there is no advantage in labor costs and material costs are higher, how does composite make sense for a cheap airplane? It doesn't. Regards, Gordon. "Ron Wanttaja" wrote in message ... On Mon, 19 Sep 2005 03:47:38 -0400, Roger wrote: On Sun, 18 Sep 2005 23:37:30 -0400, "Gordon Arnaut" wrote: Evan, I don't want to drag this out, I think some good points ahve been made -- however, I don't see why fiberglass airframe construction is going to be less labor-intensive. Once you have the moulds constructed, fiberglass lends itself well to making large compound structures as one piece. There is almost zero opportunity for automation in fiberglass construction, That depends on your thinking. Fiberglass composite also lends itself well to putting pieces together. I dunno, Roger. I've been both to the Glastar factory and the Vans factory. At Vans, a guy feeds a big piece of aluminum into a big CNC machine and whango-whango-whango out comes a big pile of RV parts. But then I go see the Glastar's fiberglass fuselage made, and its spray the release agent onto the mold, then the gelcoat, then cut pieces of fiberglass and lay them into the mold, then squeegee on some resin, then apply the foam, then apply another layer of fiberglass and more resin, etc. etc., lather, rinse, repeat, then let the assembly tie up your every expensive mold while the resin cures. Looked to me that manufacturing aircraft parts in fiberglass is a *lot* more effort...though I allow that less-skilled workers can probably be used. Ron Wanttaja P.S. Wanna hear something *really* scary? My spell checker passed "whango-whango-whango" but hiccuped on "gelcoat." |
#15
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Based on my back of the envelope analysis of the theoretical base price
of a 2 place aircraft, I think wishing for a plane costing less than 50K is nothing more than a pipe dream. I don't buy it. When I was in the Keys, I saw a two-seat UL trainer on floats. It was open cockpit (very open), and had a Rotax engine and Dacron-sailcloth covered wing, but it was $25K new. Presumably the manufacturer was making a profit. I think all your prices are WAY too high. $15K for an engine? A Rotax retails for half that. That's RETAIL - if you're a manufacturer you should be able to get a better deal. $20K for airframe components? You can buy a quickbuild kit for a pretty advanced (high-speed all-metal RV) for less. Retail. Prebuilt and predesigned for home assembly. $4K for instruments? For an IFR panel with certified components, maybe. For day-VFR, you need a non-sensitive altimeter, an airpeed indicator, a compass, and some engine gauges. The retail price on all this (assuming non-certified stuff) is maybe $1K. I think everyone pretty much expected that when the LSA rules came out, the UL trainers (2 seat) would be sold as LSA's for about the same money they cost as UL trainers - about $20K-$30K ready to fly. This isn't happening. There really are only two possible reasons. Either the LSA 'certification' process isn't really all that simple or cheap (meaning that, as with the recreational pilot and VLA, the FAA has botched the job again) or the manufacturers figure they can skim the cream at a higher price. Michael |
#16
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Ron,
& yet, when that part comes out of the mold, it is essentially flyable. With the aluminum CNC paradyme, you get predrilled holes in aluminum you then have to bend, & thousands of rivet holes you have to debur. hours, hours, & hours of deburring... |
#17
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Gordon,
All I'm saying is that there's more opportunity to do low labor per square foot of fuse with fiberglass than with aluminum, ans since we are talking about commercially built structures, that's all that matters when you are trying to get a basic airplane out the door for less than 80, or even 60K. As for using pull type rivets... do you really think any commercial entity is going to roll out insured airplanes with the equivalent of pop rivets? |
#18
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Michael,
I've interspersed my data (gleaned from today's online prices) throughout your message. Add them up yourself. I don't buy it. When I was in the Keys, I saw a two-seat UL trainer on floats. It was open cockpit (very open), and had a Rotax engine and Dacron-sailcloth covered wing, but it was $25K new. Presumably the manufacturer was making a profit. We were talking about an enclosed aircraft with a fiberglass or aluminum body, 4 stroke engine, and 2 seats with a cruse of ~100 knots. I think all your prices are WAY too high. $15K for an engine? A Rotax retails for half that. That's RETAIL - if you're a manufacturer you should be able to get a better deal. sigh I just went to a common retail website & found that a rotax 912 (the most commonly used for aircraft of the type we are talking about) lists for between 16 & 22K. The difference being the options & accessories. $20K for airframe components? You can buy a quickbuild kit for a pretty advanced (high-speed all-metal RV) for less. Retail. Prebuilt and predesigned for home assembly. On the RV site, they do in fact sell the early model RV for 11.7K, however, the finished cost is listed at 45K. That would be 10K more than my fiberglass KIS. $4K for instruments? For an IFR panel with certified components, maybe. For day-VFR, you need a non-sensitive altimeter, an airpeed indicator, a compass, and some engine gauges. The retail price on all this (assuming non-certified stuff) is maybe $1K. Er, I just bought mine & even my radio cost ~1k. If you would be kind enough to tell me where you purchase your instruments, I'll start purchasing mine from your supplier right away! I think everyone pretty much expected that when the LSA rules came out, the UL trainers (2 seat) would be sold as LSA's for about the same money they cost as UL trainers - about $20K-$30K ready to fly. This isn't happening. There really are only two possible reasons. Either the LSA 'certification' process isn't really all that simple or cheap (meaning that, as with the recreational pilot and VLA, the FAA has botched the job again) or the manufacturers figure they can skim the cream at a higher price. Michael |
#19
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Ron Wanttaja wrote:
P.S. Wanna hear something *really* scary? My spell checker passed "whango-whango-whango" but hiccuped on "gelcoat." Your spell checker has the Ted Nugent module? ![]() |
#20
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Evan Carew wrote:
As for using pull type rivets... do you really think any commercial entity is going to roll out insured airplanes with the equivalent of pop rivets? The windshields on the Bell Jetranger helicopter are held on by pulled rivets. I didn't know that until I saw one being replaced. |
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