Cambrian Akrostar

[will -0]

Posted by ron evans on 14/02/2017 15:41:32:

Hi Tony H, another fix that might prevent tip stalling would be to sharpen the LE profile for a few inches at the wing root, or add a sharpened strip to the LE at the root, much like the full size Chipmunk.

This will not lower the stall speed, but might persuade the root to stall first.

Just reading this thread, and know it's been a while, but I think the sharp edges at the root on the chippie are there to give some pre-stall buffet which you can feel if you're inside the aircraft holding the controls. This gives warning of impending stall.

Not a lot of use in RC unless you have some very fancy telemetry

Edited By will -0 on 20/04/2017 15:22:57

[Stuart Z]

Tony

Excellent news on the maiden. Clearly low and slow in a turn will not go well but you now know and clearly can manage it well. Looking forward to the video.

S

[Tony H]

Finally I have the Maiden Flight Video to show you. Slighty fast and bumpy landing .

[will -0]

That's a lovely blue sky

 

Do you have a "second flight once the pilot got the hang of landing it" video?

 

I feel that's not the most flattering for the model.

 

Edited By will -0 on 22/05/2017 08:53:36

[will -0]

Sorrry, that was probably a bit rude,

What I'd like to know is is that how it always lands or not!

[Tony H]

Hi Will,

I'm aware the landing wasn't my finest but it is the Maiden flight landing a plane that is known to drop a wing at low speed with a new engine fitted. I always keep the idle fairly high when running a new engine for the first time.
Also our strip is very uneven and has many holes in it as its is used as an MOD training ground. This really didn't help as you can see it landed fast and was almost relaunched on the uneven ground a few times.
I do intend to video more flights once my camera turns up so I don't have to rely on other people to video for me. Hopefully with a few more flights and engine runs I'll have a video with a decent landing.

It looked possible after my first landing. I always like to video the Maiden Flight though in case of a crash.

Tony H

Edited By Tony H on 22/05/2017 10:24:21

[Stuart Z]

Well done, it looks great in the air.

The landing was long and safe I think, it is clearly a fairly lively model, perhaps with a high wing loading. It was designed to be highly aerobatic so there's not going to be a lot of (read any!) natural stability and landing this sort of plane comes with practise I'm sure.

I've now put it in to my "wish list", Christmas seems not that far away and I have an unused OS 55 or 46 I could hang on the front!

S

[will -0]

Thanks

The reason for asking is that our patch is, as far as I can tell from your vid, somewhat smaller end to end and before I build mine iId love to know if that's what's required for approach speed, otheriwse it might not be practical!

[Tony H]

Thanks Stuart, I was going for the get the plane down in one piece senario on the first flight rather than the perfect landing. I did fly a couple of times after this flight with a bit better landings but I still don't trust the stall speed yet. Will- I see why you want to know but it will depend a fair bit on the weather and the site conditions etc... every site is different even if they look the same. My site can be very windy and changable as the sea is literally only about 800 metres from the tree line you see in the Video. It's possible on this landing I didn't have much head wind to slow the plane down or most likely a cross wind.
I'm sure the plane will be able to land nicely with a reasonable head wind. On this occasion the plane didn't slow as quickly as i'd expected.
I came in quick also because I wasn't completely sure what speed the stall was, and I'd already experienced it loose a lot of high in one of the turns for no apparent reason I decided to land it hot but it was a little quicker than I'd expected.

Hope this helps. I will put a new video up soon once I have more flights.

Edited By Tony H on 22/05/2017 13:14:07

Edited By Tony H on 22/05/2017 13:14:23

Edited By Tony H on 22/05/2017 13:15:41

[will -0]

Thanks

Sea breeze + tree line must make life interesting.

[Stuart Z]

Thanks Tony

[Tony H]

Here is a flight I did today in not perfect conditions, light rain, heavy cloud and changeable light wind. I took this with a wide angle Mobius HD Camera attached to my hat. I have bought the standard lens version now too as I think this is a little too wide.

Here is a slightly better landing.

Edited By Tony H on 29/05/2017 20:14:29

[will -0]

Nice one, we had that weather too, though we were the only one's "enjoying" it.,