Weight and Balance with a 2.2 Jab

[Corby202]

Hi my name is Phil Bird and this is my first Post.
For the guy's useing a 2.2 Jabiru engine. Have you had any problems getting the CofG correct??.I just wonder if I will have any problems if I choose a 2.2 Jab because of its light weight.
Thanks
Phil
Sydney Australia

[rizzz]

Hello Phil,

Don’t believe W&B is an issue but you can download an app from the Sonex Builders and Pilots foundation that helps with the CG calculations, it comes with a standard J2200 taildragger & nosewheel sample file which will give you a pretty good idea. You can download the app here:
http://www.americansonexassociation.org ... index.html

(select the “Weight and balance program for your PC” under the “Downloads” dropdown list, then click “Go”)

So you’re in Sydney,
With all the hoo haa currently surrounding the Jabiru engines here in Aus, it could actually be a great time to pick up a low time second hand Jabiru engine somewhere.
It’s a little bit of a risk and so when negotiating a price you’ll have to take into account the fact that you will probably be faced with the cost of a mandatory SB coming up in the near future to satisfy CASA.
You’ve got to assume though they will eventually come to a solution, where some see risk, others see opportunity, if I were in the market for a Jabiru aircraft, engine, I’d be hunting hard right now.

[Corby202]

Thankyou Michael
I am not far from you at Mittagong. Still undecided on which engine. A 3.3 Jab would be perfect but they are expensive. I like VW's, I have one now in my Corby Starlet but I think the climb at Mittagong (2000' asl surrounded by hills) would be marginal with a VW.
http://www.mykitlog.com/corby202/

[fjdoug]

hi Phil,
with my 2200 i don't put anything behind the seats in what is meant to be the baggage area.
i carry camping gear etc in a bag on the seat beside me and strap a duffle bag to the flap torque tube on the floor ahead of the seat.
two-up at max weight i am within the limits.
Doug from Canberra.

[andrewp]

Out of sheer curiosity, how much does a Jab 3300 cost in Aussie dollars these days?

AP
Sonex #618

[andrewp]

And hello Doug BTW!

[bnvoss]

Phil, my experience is with a nose gear Sonex. I suspect a tail dragger Sonex would have a little more problem with wt & bal using the Jab 2200. I made sure I had no extra weight in the tail section and no paint back of the wing. With this configuration and empty wt of 640 lbs, I can load passengers and fuel (but no baggage) to 1100 lbs and still stay within the cg envelope. At 1150 lb gross wt, I don't fly with less than half fuel. That way, I'm sure to stay within the calculated cg envelope. Hope that helps.

Bob Vossman, Texas
Sonex 550, jab 2200 with 440 hours

[tonyr]

Hi Phil,

I have a Jab 2200 TD and have clocked up 23 hours.. 2 to go with the test flying phase.

My empty weight is 290kg/640lbs, a bit on the tubby side for a TD. I was mindful of a tail heavy condition, so during the build I made sure any weight I was adding was ahead of the spar. I went a bit overboard with hardware and fittings around the engine bay, used an extra crossmember behind the tank to support the Dynon D180 and MGL V6 wiring harnesses. Made a subpanel for switches, cb's etc and made the instrument panel removable. No baggage compartment behind the seat. A polish job and paint on the fibreglass has also helped. My tail weight is less than Doug McLean's above as well.
Even with 40 litres of fuel, myself and no baggage in the RH seat it tends to be nose heavy if anything. Even with 10kg/20lbs of upholstery cushioning! I haven't loaded to MTOW of 1100lbs yet (which is the factory limit for 80-85hp engines by the way)
The other important factor for good climb performance is the prop, a sensenich 54 x 48 does give good climb performance but the max climb out rpm for mine is up to 3200.. I regularly see 1000-1200 ft min at 70kts. Have to watch temps though if the nose is high. The cruise speed is of course lower but mine manages 105kts 2850rpm with wheel pants and fairings.

Cheers
Tony

[tonyr]

PS Phil, there is also the Camit option for new 2200's. http://camitaeroengines.net/
Personally I wouldn't go near a second hand engine.

[Corby202]

Thanks for all the reply's.
I am surprised you guy's are not going bigger then 54" on the Prop's for Jabiru engines, Ground clearance perhaps.
Phil Bird
Mittagong
Australia