Justin's Raven

[avgas]

Hi Justin
Can you help me with the mass and balance specs please. I am in process of calculating COG of an Raven that I weighed.
Cheers
rgn AT pcwireless DOT co DOT za

[justin.schoeman]

Here is the Zenith W&B sheet. Everything measured up the same (within a mm or 2) on my plane. Except for Pilot/Pax arm, which I measured at 726mm instead of -650mm. Although everybody I have spoken to uses 650mm for their calculations.

Also, this sheet is for the speed wing. For the standard wing, the rear limit is 17.5", NOT 19.5" .

Justin

[avgas]

Thanks a lot

[justin.schoeman]

Had a short break from testing due to: broken trim servo (my fault), wx, social obligations, Christmas, etc. But I am back to testing again.

Still trying to tune the prop. I have tested with the original 57x36 prop, and there was surprisingly little difference in performance, so I have now started trimming the 60x32, to try and get the engine to the top of the torque band (3400RPM). I am now down to 58" (probably around 33" pitch). Cruise RPM @ 75% power is now 3250RPM. So ideally, I still want around 150RPM more to get the most out of the engine - but I have a feeling that shortening the prop any more will start seriously reducing prop efficiency...

Climb performance is difficult to judge with the current weather. Average climb over 1000' was 480fpm on Sunday, at 405kg take-off weight. BUT DA on the ground was 7500' (8500' at the top of the climb). So real-world performance should be a bit better. I will bring some tile cement bags on Saturday, and start pushing it towards MAUW. Will finally see if it is a two seater, or not...

A really ugly snap out of the side window - just to prove it really is still flying :

[justin.schoeman]

Someone was asking for a video of take-off and climb performance (to compare to the first flights):

http://www.youtube.com/watch?v=mWHYHNyskvE

This was 1 up and 1/2 fuel. 7200' density altitude, 10kts 90 degree cross wind. Average climb rate to circuit height (1000') was 490fpm.

Still marginal, but substantially better than climbing out at 75kts due to inaccurate static pressure!

[AndyCAP]

Good going Justin! You seem at least to be having reliability to do all sorts of tests. Keep it up!

[justin.schoeman]

No feedback in a while. I was just about to give up after my sand bag testing. Managed to get 40kg into the pax seat before getting too scared. That is the big problem with high span loading aircraft - power to climb requirements go up quickly with weight. Nett result is the the VW just isn't going to cut it for the short wing Raven.

Did a lot of research into available engines and pricing, before being contacted by Len Alford at the Jabiru factory. They have the most amazing deal on remanufactured 3300 engines - so it looks like I am getting a 120hp lump in the nose of my Raven :D .

[Loco]

No feedback in a while. I was just about to give up after my sand bag testing. Managed to get 40kg into the pax seat before getting too scared. That is the big problem with high span loading aircraft - power to climb requirements go up quickly with weight. Nett result is the the VW just isn't going to cut it for the short wing Raven.

Did a lot of research into available engines and pricing, before being contacted by Len Alford at the Jabiru factory. They have the most amazing deal on remanufactured 3300 engines - so it looks like I am getting a 120hp lump in the nose of my Raven :D .

Awesome good luck!

[RV12]

Did you study at Tukkies and stayed in Kollege te huis

Julle bliksems!!

Watter jare ?

Ek en Mak was in Taaibos - middel 80's.

Ek was in Taaibos 82 en 83 !

[justin.schoeman]

Just a brief update. After months of waiting, the various FWF bits arrived from Oz. The Jabiru factory just ran the engine in the test cell, and according to Giel, it is the best he has seen yet - a solid 2900RPM on the test prop.

All the bits and pieces should ship tomorrow, and I will start fitting this weekend!

[Jean Crous]

Good to hear Justin, keep the foties coming.
J

[justin.schoeman]

Some action at last...

First, as a sideline, I have been making a new instrument panel. Need to improve maintainability, and fix some non-ideal ergonomics on my first one. Live and learn...

Here is the new panel in its mould:

And the big fun - opening the boxes that arrived today!

Still have some work to do before hanging the engine. New battery box is just about ready. New Jabiru air box does not quite fit - so I will need to 'edit' it a bit. Laid up the components for the oil catch bottle. And need to finish the panel. But the big things are the bits that go against the firewall, behind the engine, as these must all be fitted before hanging the engine. Will see how much progress I make this weekend.

[JvTonder]

Nice going mnr!

[Jean Crous]

Good for you Justin, we are waiting anxiously..........
Jean.

[t-bird]

Best of luck mate, keep us posted.