Wednesday 1 October 2008

Charlie Fox November India

We have been pretty busy the past month, the end of summer\start of autumn always gives us a glimpse of good weather. And it was well needed, Summer 08 has been the wettest for decades according to the Metmen.

And a new arrival has made an appearance....sorry to disappoint but not a hot towel or babygrow in sight. Our new MK2 XT912 arrived at the start of September, and it has taken a while getting it up and running and (more importantly) our instructors familiar with it before letting students get their grubby paws all over it. So it is goodbye to HZ (gone to John Horan in Galway) and in with CFNI

The MK2 is slightly different to the MK1 XT, small improvements to a great design. Airborne have produced a 'Bikini' engine cowling which is easily and quickly removed for pre-flight inspections, and they have produced a windscreen which is needed now (will explain later!) Their engineers have designed a great set of hydraulic disc brakes which should be an improvement over the nosewheel setup, and the Skydat now has the latest firmware (the previous one gave some erroneous errors) The cockpit trim has changed and they have redesigned the throttle and brake pedals - again nothing major - just small welcome improvements.

The biggest change is the speed that this aircraft will fly at - out of the factory it will fly at 78mph which is quite a difference on the MK1. Thats at Hands off trim - which means hands off. The weight of your hands will take it to 80mph and beyond. And its all down to the holes in the wing!

The position of the hangpoint on a flexwing determines (along with some other things) how fast the aircraft will go. A MK2 Streak3 wing has 4 holes in the wing keel tube that can be manually adjusted. The wing parts are interchangeable with the other Airborne range, with the back hole (slowest) used for their Merlin wing. So we can only use the front 3 holes.

Out of the shipping crate the wing is set on the second hole from the front, giving the speeds above. The front hole has the aircraft sitting at nearly 85mph. All this is great for getting somewhere fast......I think its pretty obvious why we need the new windscreen!

So after a week or so of our instructors having a great time flying everywhere at 80mph...we decided to slip the hangpoint back a notch for the students :-(

Its great to have the option for a fast setting and the aircraft can still be slowed down quite easily for landing. What we need is the trike to sit naturally at a reasonable speed for training - we find 65-70 is more than enough for general flying, so back a notch it is we're afraid..... What we really need is an electric hangpoint that will move this position back and forward, I suppose that will be on the Mk3

One other noticable difference is the fuel consumption. We have a very accurate fuel flow meter in the Skydat, fantastic simple bit of kit. Anyway, we normally plan on 10-12 litres an hour for an hours flying....but this trike at the same airspeed is showing as 6-7 litres an hour with the 912 going at 3600 in level flight! A flying school's dream if it is correct

Maybe a bit of a mistake on my part - alzheimers could be starting early in my case. But the only difference is the windscreen, which I would have thought creates more drag, with us needing more engine revs? Maybe it has a different effect and as a result provides clean air to the prop at the back with less engine RPM needed???? More testing required...or get started on the alzheimers tablets.

Some pictures and more details on the way, lots of other stuff happening but will leave that for later!

Cheers, Victor
www.flyni.co.uk

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