Brand new... Old Yank metal -v- new plastic fantastic.
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It's pointless debating the relative structural strength of 750kg versus say 1200kg machines.
It's not just the interior trim the former ones do away with. Everything is really thin. Even the control cables and their attachments are cut down.
As I say, pop over to Aero this year and see for yourself. You get a lot more in terms of a "flying machine" for your £80k, and it is probably the only way to buy something brand new and shiny, but don't kid yourself that it will be built to last - especially operated on typical grass strips for years.
And the fuel flow will always be very similar for a given thrust (IAS) and a given cockpit cross-sectional area. The engine type barely comes into it. A Rotax and a Lyco will deliver very a similar SFC.
It's not just the interior trim the former ones do away with. Everything is really thin. Even the control cables and their attachments are cut down.
As I say, pop over to Aero this year and see for yourself. You get a lot more in terms of a "flying machine" for your £80k, and it is probably the only way to buy something brand new and shiny, but don't kid yourself that it will be built to last - especially operated on typical grass strips for years.
And the fuel flow will always be very similar for a given thrust (IAS) and a given cockpit cross-sectional area. The engine type barely comes into it. A Rotax and a Lyco will deliver very a similar SFC.
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Presumably the modern training market is what the Cessna Skycatcher is aimed at? Is that aircraft any more robust than the SportCruiser/PiperSport? I don't have huge experience of LSA but my Pioneer certainly needed some tidying after 500 hours. If the new breed of LSA with Restricted Type Certificates, of which there are currently only a very small number, are not anyway robust enough for training then the available modern aircraft suitable for training would appear to be very few
The structural requirements that have to be complied with for light aeroplanes (CS.23 and FAR 23), very light aeroplanes (CS.VLA) and microlights (BCAR Section S) are all basically the same.
The new US LSA category however does seem to set some rather lower standards and I imagine that those are what IO540 is describing. I had a conversation not long ago with one of CAA's more senior airworthiness engineers who clearly regarded EASA's discussions about giving those aeroplanes full Certificates of Airworthiness as barking mad. I agree with him.
G
The new US LSA category however does seem to set some rather lower standards and I imagine that those are what IO540 is describing. I had a conversation not long ago with one of CAA's more senior airworthiness engineers who clearly regarded EASA's discussions about giving those aeroplanes full Certificates of Airworthiness as barking mad. I agree with him.
G
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The flying club I'm with is currently in the process of replacing some of its 'old yank metal' (PA-28-161) with a 'new plastic fantastic' Dynamic WT9. Rotax, FADEC, glass, carbon/composite, factory new. Of course I'm looking forward to exploring the differences myself but I'm curious if anyone has experience with the WT9?
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IO is mistakenly aiming his comments at aircraft tested to CS-VLA, hence his 750kg above which only applies to VLA’s. LSA is restricted to 600kg and is a US only std.
Rod1
Rod1
The flying club I'm with is currently in the process of replacing some of its 'old yank metal' (PA-28-161) with a 'new plastic fantastic' Dynamic WT9. Rotax, FADEC, glass, carbon/composite, factory new. Of course I'm looking forward to exploring the differences myself but I'm curious if anyone has experience with the WT9?
General impressions were of a high performing, very nice looking aeroplane whose handling is mostly well sorted. There are however certainly variants with distinctly poor stalling characteristics, and most variants have far too little available payload. I'd recommend that your club check the stalling characteristics themselves of each aeroplane before accepting it, and have a good hard look at the weight and balance also.
G
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The structural requirements that have to be complied with for light aeroplanes (CS.23 and FAR 23), very light aeroplanes (CS.VLA) and microlights (BCAR Section S) are all basically the same.
One can't put figures on everything, which is why some planes are a lot stronger than others, in terms of in-flight breakups over many years.
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I think we are in danger of comparing apples with oranges here. Someone has already pointed out the difference between LSA (an American thing) and CS-VLA (European). It seems to me that a number of the VLAs also fit quite nicely in the LSA category with a bit of tweaking - I wonder why. 
Regardless, I thing the broad-brush that some use to criticise these new pretenders is, err, rather broad. For example, take the Aquila A210 which is a VLA and most definitely a fine aircraft. It may be expensive and it may get tatty in a club environment but............
Regardless, I thing the broad-brush that some use to criticise these new pretenders is, err, rather broad. For example, take the Aquila A210 which is a VLA and most definitely a fine aircraft. It may be expensive and it may get tatty in a club environment but............
There is however a big potential difference between 2 planes, both rated at say +3.6G or whatever, in that one can be a lot more robust than the other.
One can't put figures on everything, which is why some planes are a lot stronger than others, in terms of in-flight breakups over many years.
One can't put figures on everything, which is why some planes are a lot stronger than others, in terms of in-flight breakups over many years.
Cessna and Piper design to my certain knowledge, as close to the regulatory limits as they can, but have little history of in-flight breakups.
G
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The new US LSA category however does seem to set some rather lower standards and I imagine that those are what IO540 is describing. I had a conversation not long ago with one of CAA's more senior airworthiness engineers who clearly regarded EASA's discussions about giving those aeroplanes full Certificates of Airworthiness as barking mad. I agree with him.
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Cessna and Piper design to my certain knowledge, as close to the regulatory limits as they can, but have little history of in-flight breakups.
To the best of my knowledge Piper and Cessna design to 3.8g plus a 1.4 safety factor, VLAs to 3.8g plus a 1.5 safety factor, and UK microlights to 4g plus a 1.5 safety factor. Pretty much the same numbers all round - it's the LSA (and German or Czech Ultralights, who really don't apply appropriate factors) that would worry me.
What are your statistics on in-flight breakups by the way? I'm not aware of any significant incidence in certified (or UK Permit) aeroplanes. I can think of a PFA Cuby, and a CofA PA28, both about ten years ago, but little else.
G
What are your statistics on in-flight breakups by the way? I'm not aware of any significant incidence in certified (or UK Permit) aeroplanes. I can think of a PFA Cuby, and a CofA PA28, both about ten years ago, but little else.
G
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If Cessna are so good at designing/building aircraft how come:
The average 172 has 13 fuel drains
The average club 152/172 has more ripples on its firewall than a Cadbury's Flake
The average 152/172 goes through nosewheel shimmy dampers (thank you Lord
) more quickly than I can type.
[tongue removed from cheek]
The average 172 has 13 fuel drains
The average club 152/172 has more ripples on its firewall than a Cadbury's Flake
The average 152/172 goes through nosewheel shimmy dampers (thank you Lord
) more quickly than I can type.[tongue removed from cheek]
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I wonder how many of these plastic fantastic kits will still be flying 48 years from now. My twin comanche from 1963 (previously owned by Douglas Bader) is worth more today then it cost new. Ofcourse a lot of money has gone into maintenance over the years.
Now if only there was an STC for mogas on the IO320............
Now if only there was an STC for mogas on the IO320............
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“I wonder how many of these plastic fantastic kits will still be flying 48 years from now”
Well I sincerely hope mine is not. I hope it will have been scraped and replaced by something much more efficient.
Rod1
Well I sincerely hope mine is not. I hope it will have been scraped and replaced by something much more efficient.
Rod1
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Cows getting bigger
Quote:- The average 152/172 goes through nosewheel shimmy dampers (thank you Lord ) more quickly than I can type.
I have two Cessna 152's with more than 3000 hours in service with my company and right at the start I chucked away the old and leaking shimmy dampers and have had no more problems, I would guess that the problem is that the dampers on the aircraft that you fly are not being maintaned IAW the maintenance program or should have been replaced years ago.
I have two Cessna 152's with more than 3000 hours in service with my company and right at the start I chucked away the old and leaking shimmy dampers and have had no more problems, I would guess that the problem is that the dampers on the aircraft that you fly are not being maintaned IAW the maintenance program or should have been replaced years ago.
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No one has mentioned the 'super factor' which is applied to composite aircraft. This is an additional 50% reserve which is intended to compensate for the difficulty in inspecting many of the components and joints.
So if the airframe has been carefully put together then theoretically a composite airframe should be a lot stringer and so last considerably longer. It is this factor which largely eliminated the potential weight saving from composites. So long as it exists it would be reasonable to expect composite airframes to be us for a vedry long time...
So if the airframe has been carefully put together then theoretically a composite airframe should be a lot stringer and so last considerably longer. It is this factor which largely eliminated the potential weight saving from composites. So long as it exists it would be reasonable to expect composite airframes to be us for a vedry long time...
If the superfactor were not used, you'd definitely see a significant number of in-flight breakups.
German Ultralights in the 1990s were commonly composite, they certified without the superfactor, and the in-flight failure rate was not healthy.
Indeed, many airworthiness engineers worry that the factor is still too small.
Incidentally, the composite superfactor has two components: 20% for material variability, and 30% for through-life degradation. You can reduce it down to 30% by testing a significant batch of materials at maximum representative operating temperatures.
G
German Ultralights in the 1990s were commonly composite, they certified without the superfactor, and the in-flight failure rate was not healthy.
Indeed, many airworthiness engineers worry that the factor is still too small.
Incidentally, the composite superfactor has two components: 20% for material variability, and 30% for through-life degradation. You can reduce it down to 30% by testing a significant batch of materials at maximum representative operating temperatures.
G
