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Re the Sapphire


microman

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Hi - just happened onto this website and as a former Sapphire owner thought i would share my experience. My Sapphire was a very early one, with the fabric-covered short wings and a thick wing-section - originally with a 377. I imported it from Ballina to NZ in 1992 and fitted a 503 with a 3-blade Ivoprop. The aircraft performed very well, but I do remember constant problems with pitch changes, as it had no trim whatsoever- you had to fly it all the time and it was a handful in turbulence. For all that, it was a wonderful aircraft - it would climb at any speed above the stall, and it was easy to land - even without flaps - you just had to get the speed back. I would love to have the aircraft back in my hangar, and would fit a trim tab, brakes, and wing tanks (to replace the seat tank).

 

 

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Still a great little ANO 95-10 aeroplane. The later ones had a bungy style trim mechanism from memory.What part of NZ are you from?

Rolleston near Christchurch. I currently fly a Jodel D18, having just sold a Skyranger. Hoping to get the Sapphire back one day as a project, now that I have accumulated the necessary skills to modify it the way I would like. Given the aircraft you have flown, I can't imagine you in a Drifter - I took a flight with Wayne Fisher once in his Drifter - found it a bit unnerving I have to say!

 

 

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Is that you Graeme? I remember a very nice Yellow D18 which made centrefold of our Sport Pilot magazine...

Thats me - I didn't realise ZK-JVG was famous - any chance of a copy of the photo? I'm off to Gore in the deep south next weekend for the annual RAANZ fly-in - weather permitting - although we have had a fabulous summer here.

 

 

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  • 2 years later...

Well a few months ago I managed to get my Sapphire back - its an original 95.10 model - short wings with part fabric, fuel tank behind the seat, no flaps etc etc. Almost finished restoring it, and have fitted a twin-carb 503. Just have a couple of concerns and wonder if any other Sapphire owners or previous owners can offer advice - the 503 is quite a bit heavier than the original one I had on it 20 years ago what with electric start, twin carbs, fan cooling etc. I seem to recall that all Sapphires tended to have an aft C of G and wonder whether mine might now be too far aft - I guess the only way to know will be to do a W & B. Also, the 503 has a gearbox with the 2.58:1 ratio - I imagine the 2:1 or 2.24:1 would be preferable, especially as the 3-blade Ivoprop has had to be cut back to just under 50 in diameter to clear the tail-boom. Any advice appreciated.

 

 

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The later version Sapphires had a slight sweep-back in the wings to get the CofG better positioned.

 

Many sapphire owners, not happy with the bungee trim system, have fitted 'anti-servo' trim tabs to the all flying tail, and can now fly hands off.

 

Not much else needed on the Sapphire, it was pretty well sorted from the start.

 

There may be the odd AD somewhere in the system, the top rudder pivot rings a bell....?

 

 

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Many thanks for that pylon500 - I didn't know about the sweepback - that certainly explains why the later models could handle the 503. I have also fitted a trim tab and hope that I can overcome any slight tail-heavy tendency with that. Of course if its majorly tail-heavy I will have to think again. And I will check the top rudder pivot.

 

 

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And the AD is from a 95.25 .... the early 95.10 rudders are not the same fitting - some were the same some are different and the AD cannot apply as its physically not possible for the failure to occure ... mine is the original fabric wing long span with KFM and it has the early fin fitting and the early aileron linkages that are completely different from the late 95.10s and the 95.25's

 

But if you want to check the AD is here

 

https://www.raa.asn.au/safety/airworthiness/#Sapphire

 

There is definitely an AD issue by RAAus on the rudder top pivot.

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  • 1 month later...

Finally flew my 95.10 Sapphire today for the first time after a total restoration - its fitted with a twin-carb 503, and even with the Ivoprop on full coarse it revs out at 6800 static so I can see that I will need to get the 2.24 gear ratio rather than the 2.58 on it currently as prop diameter is limited to 50 inches which is a bit small.

 

Otherwise, plenty of power available and I even managed to 3-point it on landing.

 

1541103449_IMG_20151023_125322(Large).jpg.a4a71c1da5f2c927f0a2c544de1654bf.jpg

 

 

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Ok as it happened, and the test flight didn't throw up any problems in that area. I have fitted a trim tab, but on the first short flight didn't get a chance to see what effect it might have. Stick pressure was light with no obvious tendency to pitch up.

 

 

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Ok as it happened, and the test flight didn't throw up any problems in that area. I have fitted a trim tab, but on the first short flight didn't get a chance to see what effect it might have. Stick pressure was light with no obvious tendency to pitch up.

Fitting a simple trim tab may help a little although what's really needed is an adjustable 'Anti-Servo' tab to give better feel and stability.

The 'Stock' Sapphires I have flown usually have a tendency to pitch down in cruise if left 'stick free'.

 

There are various stories of people losing items from the (open) cockpit after such 'bunts'.

 

An anti-servo tab will cure this problem.

 

 

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Flew the Sapphire again today and only did one circuit - two issues - firstly the Rotax 503 runs smoothly up to 4500 rpm, then has a rough patch, surging etc, until it hits 6000 rpm and it takes off again - all the way to 7000 - if I let it go that far! My theory is that it is either running too lean or too rich in the mid-range and the circlip on the jet needle needs to be moved up/down (not sure which).

 

Secondly, the pitch seems to be very sensitive - more so than I remember from when I last flew it 15 years ago. It is a constant effort to avoid overcontrolling and hence PIO. The stick is very short and I am contemplating adding an extension at the top to reduce its sensitivity. Any thoughts from anyone?

 

 

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If running a twin carb two stroke, you really need a dual EGT to see what's happening.

 

A two stroke MUST have an EGT, it's as important as an oil pressure gauge on a four stroke.

 

Also check that the carbi's move the same..

 

If the aircraft feels a bit sensitive than last time, have you lost weight?

 

Are you the same weight with a now heavier engine?

 

I know many sapphires with lead in the nose...

 

Stick extension may work, but it's more likely an underlying warning of something else out of whack.

 

 

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I have a single EGT - with the sender at the junction of the two exhaust manifold outlets - temps 600-650C so a little on the high side - have checked the carb slides and no issue there - I've gained 10kg since I last flew it (which probably compensates f0r the 10kg heavier engine) but I dont think thats the issue - stick pressure is negligible but tiny movements seem to have an exaggerated effect..

 

Will try for a richer mixture and see if that helps the mid-range.

 

 

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If you have a single EGT probe at the Y junction, it is probably too far away from the port for a correct reading (would read low), so you need to raise the needles (circlip towards the pointy end)

 

If your prop is not absorbing the power, that will also give you a tendency to run hot, is it two or three blade?

 

Do you still have the original 447?, it should have had a 2.21:1 box.

 

It should go onto the 503..

 

 

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Thanks pylon500 - You obviously have some experience of Sapphires - and 2-strokes - appreciate your input.

 

You are right - the prop is not absorbing the power (even though its a 3-blade Ivoprop at full coarse) - due to its limited diameter - but I plan to get the 2.2:1 ratio gears and swap them - that should help, because not only will it give me some more revs at the prop but it should cut back the engine revs.

 

Will also raise the needles as you suggest.

 

 

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