Brand new... Old Yank metal -v- new plastic fantastic.
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"Plastic" doesn't save much weight. Today's very light types have been achieved by using minimal-strength materials and structures, and stripping out "luxury" items like interior trim.
Pressing on the cowling of a typical 450kg type with one finger deflects the material about 1"
Hardly suprising.
This delivers a significantly lower cost means of getting airborne than previously possible, and on paper at least they claim the same G ability as certified types, but there is no denying lots of corners have been cut.
Pop down to the Aero show at EDNY in April this year and have a good look around to see how it is done. They have hangars full of this stuff.
Pressing on the cowling of a typical 450kg type with one finger deflects the material about 1"
Hardly suprising.This delivers a significantly lower cost means of getting airborne than previously possible, and on paper at least they claim the same G ability as certified types, but there is no denying lots of corners have been cut.
Pop down to the Aero show at EDNY in April this year and have a good look around to see how it is done. They have hangars full of this stuff.
Originally Posted by IO540
"Plastic" doesn't save much weight.
). So basically, plastics doesn't save the weight as much as one would expect, but I rather do high-load manuevers (staying in the limits of course) in any new aircraft (plastic or metal) than in 40 years old spamcan
Do I remember right that, for the strength to weight ratio, aluminium scores best, followed by wood, only then composites, and steel last?
As I understand (and as already mentioned higher up) the main advantage of composites is in the easy creation of complex curves. Carbon-fibre does seem to offer substantial weight savings, hence its use in the latest generation of airliners.
For industrial production, composites will be more expensive than the other materials due to the lots of manual labour involved.
So I would expect the optimal aircraft to be built of aluminium, with complex bits such as the tips and roots of wings made of composite.
As I understand (and as already mentioned higher up) the main advantage of composites is in the easy creation of complex curves. Carbon-fibre does seem to offer substantial weight savings, hence its use in the latest generation of airliners.
For industrial production, composites will be more expensive than the other materials due to the lots of manual labour involved.
So I would expect the optimal aircraft to be built of aluminium, with complex bits such as the tips and roots of wings made of composite.
Depends what you mean by "strength" Jan - tensile? compressive? buckling?
There's also huge cost implications - CFRP for example will beat anything, but at huge cost.
Materials engineers use something called a "Figure of Merit" that analyses a component's strength requirements, and done well it incorporates material and manufacturing costs to show the best material for a particular application. Even then however, it gets more complicated because you really don't want 12 different material/technique combinations in a light aeroplane because of the huge equipment and training overheads that imposes on you, when you'd rather be slightly sub-optimal but only have 5 processes in a particular aeroplane.
It was this use of far too many materials, in my opinion, that was one of the main reasons that British company CFM folder (they used to build a rather nice little aeroplane called the Shadow). The aeroplane was original designed for amateur builders and for them, having a dozen different techniques to learn was fun, but in a factory environment it was a disaster and they just couldn't build it economically.
G
There's also huge cost implications - CFRP for example will beat anything, but at huge cost.
Materials engineers use something called a "Figure of Merit" that analyses a component's strength requirements, and done well it incorporates material and manufacturing costs to show the best material for a particular application. Even then however, it gets more complicated because you really don't want 12 different material/technique combinations in a light aeroplane because of the huge equipment and training overheads that imposes on you, when you'd rather be slightly sub-optimal but only have 5 processes in a particular aeroplane.
It was this use of far too many materials, in my opinion, that was one of the main reasons that British company CFM folder (they used to build a rather nice little aeroplane called the Shadow). The aeroplane was original designed for amateur builders and for them, having a dozen different techniques to learn was fun, but in a factory environment it was a disaster and they just couldn't build it economically.
G
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“"Plastic" doesn't save much weight. Today's very light types have been achieved by using minimal-strength materials and structures, and stripping out "luxury" items like interior trim.”
Unfortunately the term "Plastic" covers a big area. Certainly, GRP is not going to save you much, but carbon fibre will save you a lot, at significant extra cost. If you compare two aircraft in the same class with the same g loading, engine and similar props it is possible to get an idea of the magnitude of the saving;
MCR01 club (lots of expensive carbon) empty weight 253kg
SportCruiser (much lower cost, metal) empty weight 335kg
Both aircraft have been tested to CS-VLA by the same organisation, both have the same engine, the MCR has a VP prop, the SportCruiser in my example has fixed pitch.
I have a friend who is designing an aircraft to lift a 90kg pilot on 24hp to cruse at 90kn. His spar is carbon, as are some of the other critical and heavy bits, the rest is wood, which is light but very time consuming to work with.
Rod1
Unfortunately the term "Plastic" covers a big area. Certainly, GRP is not going to save you much, but carbon fibre will save you a lot, at significant extra cost. If you compare two aircraft in the same class with the same g loading, engine and similar props it is possible to get an idea of the magnitude of the saving;
MCR01 club (lots of expensive carbon) empty weight 253kg
SportCruiser (much lower cost, metal) empty weight 335kg
Both aircraft have been tested to CS-VLA by the same organisation, both have the same engine, the MCR has a VP prop, the SportCruiser in my example has fixed pitch.
I have a friend who is designing an aircraft to lift a 90kg pilot on 24hp to cruse at 90kn. His spar is carbon, as are some of the other critical and heavy bits, the rest is wood, which is light but very time consuming to work with.
Rod1
I have a friend who is designing an aircraft to lift a 90kg pilot on 24hp to cruse at 90kn. His spar is carbon, as are some of the other critical and heavy bits, the rest is wood, which is light but very time consuming to work with.
A follow up point. Personally I think that materials is one of the least interesting ways of improving aeroplanes.
We all know about avionics options - just for example I did a couple of hours yesterday with a Garmin Aera sat on the top of the instrument panel. The amount of mental capacity it freed up for me to enjoy the flying and concentrate on my situational awareness was impressive. Not only that, but the ability it gives me on a cross country to cut VERY close to controlled airspace and danger areas without entering them saves me a lot of time and fuel: I think that a reasonable moving map GPS probably pays for itself in under a year of touring flying.
Engines? The Rotax 912 has massive advantages for light aviation, even if it still has it's faults - it's cheaper, lighter, easier to operate, and burns less fuel than equivalent "Lycontinentals". Just look at what it's done for the new Tecnam twin! Diesel light aircraft engines are still in their infancy, but they'll come.
Ergonomics? - This is the bit that's being most ignored at the moment, but there's been a lot of work in improving cockpit ergonomics and handling for best safety (see the article in the latest GASCo Flight Safety for example), some manufacturers are using this - I know that Cessna has in the C162, but frankly some of the latest generation of light aeroplanes are years behind their 1960s competitors in this regard. The problem is that whilst it improves safety, it doesn't make aeroplanes "sexy" (indeed, possibly the opposite).
G
We all know about avionics options - just for example I did a couple of hours yesterday with a Garmin Aera sat on the top of the instrument panel. The amount of mental capacity it freed up for me to enjoy the flying and concentrate on my situational awareness was impressive. Not only that, but the ability it gives me on a cross country to cut VERY close to controlled airspace and danger areas without entering them saves me a lot of time and fuel: I think that a reasonable moving map GPS probably pays for itself in under a year of touring flying.
Engines? The Rotax 912 has massive advantages for light aviation, even if it still has it's faults - it's cheaper, lighter, easier to operate, and burns less fuel than equivalent "Lycontinentals". Just look at what it's done for the new Tecnam twin! Diesel light aircraft engines are still in their infancy, but they'll come.
Ergonomics? - This is the bit that's being most ignored at the moment, but there's been a lot of work in improving cockpit ergonomics and handling for best safety (see the article in the latest GASCo Flight Safety for example), some manufacturers are using this - I know that Cessna has in the C162, but frankly some of the latest generation of light aeroplanes are years behind their 1960s competitors in this regard. The problem is that whilst it improves safety, it doesn't make aeroplanes "sexy" (indeed, possibly the opposite).
G
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"His name wouldn't be Michel Colomban, by any chance?"
No, his machine has a max pilot weight of less than 90kg, but the aircraft does use the same engine / prop.
BR,
Rod
No, his machine has a max pilot weight of less than 90kg, but the aircraft does use the same engine / prop.
BR,
Rod
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Ex FSO,
(excuse the thread drift, but the "old Yank metal" will have new plastic floats!)
My diesel 182 project is a work in progress, as I am still waiting for the SMA engine I ordered last March. It will be installed in accordance with the SMA STC for the 182. To this, I will add other mods, primarily amphibious floats. All of this is for a Norwegien client.
SMA's shift of emphasis to their new "E" model engine has caused a delay in our original plans, so we wait... also watching with interest what the Continental does under Chinese direction....
I have promissed SMA that I will take the 182 amphib to Oshkosh for their display, if they get an engine for me time to complete all the mod work!
(excuse the thread drift, but the "old Yank metal" will have new plastic floats!)
My diesel 182 project is a work in progress, as I am still waiting for the SMA engine I ordered last March. It will be installed in accordance with the SMA STC for the 182. To this, I will add other mods, primarily amphibious floats. All of this is for a Norwegien client.
SMA's shift of emphasis to their new "E" model engine has caused a delay in our original plans, so we wait... also watching with interest what the Continental does under Chinese direction....
I have promissed SMA that I will take the 182 amphib to Oshkosh for their display, if they get an engine for me time to complete all the mod work!
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Under built !
So far in less that a year maintaining one of these VLA's I have seen landing gear cracks, exhaust system cracks and a very pooly built brake system all on aircraft with less than 150 hours on them.
It won't be long before the steps fall off and there are big dents in the roof.
What the training industry needs is Lycoming to get the FADEC controled mogas engine into the market and give the Cessna 152 another thirty years of life.
It won't be long before the steps fall off and there are big dents in the roof.
What the training industry needs is Lycoming to get the FADEC controled mogas engine into the market and give the Cessna 152 another thirty years of life.
Last edited by A and C; 2nd Jan 2011 at 08:09.
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Mickey
I work on a number of this type of aircraft but I don't see it has any value in picking this type out, the problem is that most of the VLA's are under built in terms of robustness.
I was of the opinion when I first looked at the current crop of VLA's that most would make very good private or small group aircraft aircraft but would never take the treatment that is dished out to flying club aircraft. I have had to adjust my opinion in the face of the failure of parts of aircraft that are in service with very careful private owners.
The fact that most of this type of aircraft are now getting upgraded parts to replace the items that are failing and these parts are all much better built however with this comes more weight and this is most critical on VLA,s.
I have no doubt that as a private aircraft these types will get "sorted" but the stunning performance numbers will be blunted by the weight increase that will be required by the need for reliablity.
I expect to find a number of conflicting opinions posted below from fans of this type of aircraft but all I can say is most of the people don't have to put their name to the paperwork for the CAA permit or LAA release to service.
I work on a number of this type of aircraft but I don't see it has any value in picking this type out, the problem is that most of the VLA's are under built in terms of robustness.
I was of the opinion when I first looked at the current crop of VLA's that most would make very good private or small group aircraft aircraft but would never take the treatment that is dished out to flying club aircraft. I have had to adjust my opinion in the face of the failure of parts of aircraft that are in service with very careful private owners.
The fact that most of this type of aircraft are now getting upgraded parts to replace the items that are failing and these parts are all much better built however with this comes more weight and this is most critical on VLA,s.
I have no doubt that as a private aircraft these types will get "sorted" but the stunning performance numbers will be blunted by the weight increase that will be required by the need for reliablity.
I expect to find a number of conflicting opinions posted below from fans of this type of aircraft but all I can say is most of the people don't have to put their name to the paperwork for the CAA permit or LAA release to service.
There's a parallel there I think A&C in the microlight world.
Microlights have been being made down to a low weight limit for over 30 years, whilst meeting pretty much the same structural requirements as VLAs (JAR-VLA, which is now CS.VLA was actually based upon BCAR Section S, the UK microlight regulations).
Some microlights have definitely proved to be robust enough to last for years in a club environment - the Thruster and AX3 for example, and there's a Shadow I know of that's done 4000 hours in a flying school - although that's probably an exception. On the other hand, many: the Chevvron and Spectrum for example (interestingly both mainly composite!), which were really well regarded when they came out in the late 80s just haven't lasted and there are only a few of each still flying.
I'm sure the same will prove the same for the new crop of VLAs - some will last the course, some won't. It's certainly interesting however to conject which ones. And whether there will be an obvious metal:composites split.
G
Microlights have been being made down to a low weight limit for over 30 years, whilst meeting pretty much the same structural requirements as VLAs (JAR-VLA, which is now CS.VLA was actually based upon BCAR Section S, the UK microlight regulations).
Some microlights have definitely proved to be robust enough to last for years in a club environment - the Thruster and AX3 for example, and there's a Shadow I know of that's done 4000 hours in a flying school - although that's probably an exception. On the other hand, many: the Chevvron and Spectrum for example (interestingly both mainly composite!), which were really well regarded when they came out in the late 80s just haven't lasted and there are only a few of each still flying.
I'm sure the same will prove the same for the new crop of VLAs - some will last the course, some won't. It's certainly interesting however to conject which ones. And whether there will be an obvious metal:composites split.
G
Another example of a rugged microlight that can cope with the hard life a plane gets in training is the Rans S6 Coyote. Like the Shadow, this plane was not designed to be the fastest sleekest sexiest around, it simply does its job of pleasure flying.
G
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Is there any way to inspect a composite hull+wing structure for hidden damage?
There have been too many in-flight disintegrations following an unreported ground taxi incident, in composite (incl. wood) aircraft.
There have been too many in-flight disintegrations following an unreported ground taxi incident, in composite (incl. wood) aircraft.
Quote:
Originally Posted by Jan Olieslagers
Another example of a rugged microlight that can cope with the hard life a plane gets in training is the Rans S6 Coyote. Like the Shadow, this plane was not designed to be the fastest sleekest sexiest around, it simply does its job of pleasure flying.
Although as a kitplane, I think that in most countries the S6 can't be used for commercial training. It certainly can't in the UK anyhow.
Originally Posted by Jan Olieslagers
Another example of a rugged microlight that can cope with the hard life a plane gets in training is the Rans S6 Coyote. Like the Shadow, this plane was not designed to be the fastest sleekest sexiest around, it simply does its job of pleasure flying.
Although as a kitplane, I think that in most countries the S6 can't be used for commercial training. It certainly can't in the UK anyhow.
Not clear what you mean by "commercial training", though - all of my training was done in club environments.
Commercial: thank you, I did study English at school. Are you really implying there is training available that one does NOT have to pay for? Are you then saying that ALL training is commercial?
As for the rules: yes they do vary between countries. And even the rules that ARE identical between countries often get widely different interpretations.
As for the rules: yes they do vary between countries. And even the rules that ARE identical between countries often get widely different interpretations.
In the UK, training on type is routinely done by experienced pilots within syndicates. I've certainly never either paid, or been paid, for that sort of training.
G
G