Sapphire relaunch?

[Dafydd Llewellyn]

Here are some actual comparative data from aircraft for which I prepared the weight & balance data in the last couple of years. Work it out yourself.

 

 

 

[Oscar]

Ironically you started your post out with "Generalisations!!" .....

You really should get used to Carbon Fiber because it's coming right now in many big ways into most people's lives, don't be afraid.

Your fundamental lack of understanding of both the primary and secondary nature of the material would be hilarious, if there weren't a serious side - sec0ndary safety of c/f structures. Being able to look up Wiki articles and regurgitate them as your own knowledge doesn't cut it, sunshine.

 

c/f is a superb material, right up to the point where it isn't, and beyond that point it's as useful as a chocolate hammer. No, that's unfair - if you're being 'protected' by a c/f structure, you'd be better off with a chocolate hammer, because at least it won't tear you to shreds.

 

 

[facthunter]

Tastes better too. Nev

 

 

[bexrbetter]

Being able to look up Wiki articles and regurgitate them as your own knowledge doesn't cut it,

Problem with Wiki is it's a public source so you never know what nonsense you find ...

 

 

..... but it's true that I wasn't born with the info in my head and have had to learn it over many years.

 

Reading, discussion, going to school and simply living is where we all aquire our knowledge from, no one is exempted from that process.

 

because at least it won't tear you to shreds.

I can post tons of video's of people crashing in carbon fibre cars and sailplanes and walking away, do you have evidence to support your claim?

 

From the other side of the fence, sadly, I can also post incidents of people being torn to shreds in aluminim and fibreglass planes and cars as well, stating that it is solely due to the material used is of course nonsense but I'd take CF over the other 2 and if I hit something hard enough to shatter it then it would be the stop that kills me not the material.

 

 

[facthunter]

The material kills you when you are working with it incorrectly. I understand CF isn't good in compression.(broadly speaking). Nev

 

 

[Downunder]

I believe boats use kevlar over c/f because it will flex but not break but it's probably too heavy for aircraft use.

 

I have seen a kevlar/carbon cloth which is quite interesting.

 

I'm just a casual observer by the way. Don't string me up...............

 

 

[dj_rex]

Does the idea of a ballistic parachute ease everyone's mind?

 

 

[David Isaac]

It would ease the mind of many, but not necessarily me.

 

 

[Dafydd Llewellyn]

Definitely not mine. If you can't pass spin testing; fundamental marketing technique - if you have to have an inconvenient "fix", paint it red and make an advertising feature of it

 

 

[David Isaac]

Dafydd, was any spin testing done on the Sapphire?

 

 

[Dafydd Llewellyn]

Not to my knowledge - and no formal testing is on record, also to my knowledge; it was not required by CAO 95.25.

 

 

[David Isaac]

.............. also to my knowledge; it was not required by CAO 95.25.

I have never really understood why spin testing requirement was not there, especially given the nature and use of the aircraft.

Wasn't the Sapphire one of the first ultralights tested and certified to the then ANO 95.25?

 

 

[Dafydd Llewellyn]

Yes, it was. I never understood why spin testing was not there, either; however I suspect the Sapphire would have been very difficult to test without exceeding its flight envelope limits. The spin test requirement was not there in CAO 101.55 either - tho it was done for both Skyfox and Jabiru.

 

 

[David Isaac]

Ironically I think the Sapphire was also technically an ANO 95.10 aircraft as well was it not? However in comparison to the original 95.10 types it was very fast and slippery.

 

Aircraft like the Scout, B1RD and Frank Bailey's Mustang were single surface wing and very slow. Chances of serious injury from a prang were less than falling off a trail bike. These early single surface machines were 'relatively' safe compared to much faster later machines (e.g Sapphire). I remember in the early 80s trying to stall and spin (yes call me stupid then) Frank Bailey's Mustang, it wouldn't clean stall, it just entered a mush sink rate like a big parachute. The only real stall could be achieved was by pulling it up into a hammer head style stall and all it would do is drop the nose rapidly and start flying again in what felt less than a 50 ' height loss. Every attempt I made to stall and spin failed , ( I was GA aerobatic rated then) it would simply start flying again. I know from conversations with Frank back then (I spent a lot of time with him in those days) it was the original intent of his 95.10 design as they were designed to 'teach yourself to fly'. So we had the original un-spinnable single surface wing 95.10 machines so no spin testing regimes or requirements and then the slippery versions like the Sapphire which was probably quite spinnable (my opinion) .... But 'we' wanted faster and heavier and higher and then two seat trainers, that was when we needed real design and that is where the major compromises began IMHO.

 

 

[Dafydd Llewellyn]

The Sapphire may have started out as a 95.10; Scott was selling them before 95.25 came along. No, "real" trainers were mandated by HORSCOTS. Yes, people wanted them; but it was HORSCOTS that pushed CASA into creating first CAO 95.25 and then CAO 101.55. That was when the AUF really started its main growth surge.

 

 

[bexrbetter]

I believe boats use kevlar over c/f because it will flex but not break but it's probably too heavy for aircraft use.I have seen a kevlar/carbon cloth which is quite interesting.

I'm just a casual observer by the way. Don't string me up...............

They use a Kevlar matrix to stop the CF splintering.

 

The Kevlar fibres are actually far stronger than the surrounding resins and can literally cut themselves through and that's one of the reasons it fell from favour along with price. Most fiberglass product including CF has come way down in price but Kevlar has barely moved, probably due to how much the Military purchases.

 

Many major boat builders have gone all the way back to polyester resins albeit much better choices of materials of the genre now and layup/matrix techniques.