SH in Moscow - we did it!

[twistair]

This is it:

http://delta.wtr.ru/files/shfirst002.jpg

Yesterday our first SH made it's first pattern over the airfield. I will write something more about impressions and results slightly later - just wanted to share that... that... Ah, most of you know that damn feeling - when the device you was building for months (sometimes - years) becomes airborn.



(more poor videoshots can be seen here (http://twistairclub.narod.ru/spawk/firstflightengl.htm)

Fly fun!

[Jim]

Congratulations!! :) :) :)

Do I see four rotor blades? :confused:

Let us know more ;)

Jim

[Vance]

Congratulations Alex and thank you for shairing your special moment. That is a most interesting rotor head. I would very much like to learn more about what you have there. Thank You, Vance

[twistair]

OK, guys,

Now let me report some facts, details and impressions.

This aircraft was assembled right according to AAI drawings and instructions less rotor brake lever

which we moved to the center mast between crew heads. This was done for some reasons:
1) too many controls in the centre part of cabin doesn't seem practical. Since the rotor brake isn't used inflight it may be moved away from the closest to pilot's hands and eyes area.
2) this mod shortens the brake cable though this reason has not very big practical sense - you save maybe one pound of weight and make lever operating just slightly easier. First reason was really main and
3) Putting the brake lever between pilots' heads gives you an excellent place to hang headsets on :)

All other parts of aircraft were assembled without any mods - we only replaced AN hardware with metrical (aircraft grade, sure) ones somewhere - just in case.

We measured static thrust with 72" WarpDrive and then with 69" (not 70" as I stated in previous thread - it's really 175 cm) Lugansk prop - found that Lugansk prop works slightly better and we can save ca.17-18 lbs weight on it. Thus we installed Lugansk and got 280-285 kg static thrust on it, I've wrote about this in previous thread.

Empty weight (complete with oil, coolant, radio and headsets) is 380 kg. The only additional things we've installed are Icom A110 transciever (heavy thing - when I ordered it I simply missed it's weight - it has a speakerphone&amplifier inside which is absolutely unnecessary in gyro), Flightcom mc403 intercom and a couple of simple Flightcom headsets. Putting antenna in front of windshield we also got a good point for slip strip.

Hangtest showed (20 kg of fuel):
-5.5 deg (nose down) - pilot 65 kg
-6.5 deg - same pilot plus 75 kg co-pilot
-7 deg - same pilot plus 95 co-pilot

All rotorhead and controls stops were adjusted according to AAI recommendations.

Prerotator gave us solid 180 rrpm (+15 deg C OAT) after some minor adjustments.

Prior to install the rotor we make some driving training to become familiar with throttle, brakes and pedals.

Test pilot was Dmitry Rakitskiy, that same macho who performs Dominator and Hunter flying in known videos. I played as a ballast in the right seat :) and a voice informator on demand (" airspeed 80...85...90...120...110" etc) - this is our old practice which helps to make testing more effective since test pilot can concentrate more on other details of flight envelope.


Weather conditions were almost ideal: +15 deg C OAT, 55-60% RH and 5-6 m/sec stable wind mostly

along the runway. Runway - 400 m (meters, not miles ;), concrete, +200 meters above sea level.

Due to this wind we've got 200-210 rrpm on prerotator and tried some times to spinup rotor on low roll speeds. Rotor reacts very well, without any tendency to flap and it takes probably 30 - 50 meters of roll to spin it up to 260-270 rpm.
Aircraft right after take-off is lazy at low airspeeds but becomes friendly starting from 50-60 kmh. Yes, we took off at low airspeeds, lower than Jim Mayfield recommended me - there was a reason for this which I will tell you about some later. That day we flew at no more than 120 kmh airspeed (indicated, cannot tell this time if this was true airspeed) and I was surprised that it flies this airspeed at only 4000 engine rpm. Will check if things are really that good. Rotor rpm were 300-310 @ 560 kg take-off weight.
Another pleasant thing was that rotor (fly from the box - literally) is very smooth. No uncomfortable shake at seat/cabin nor at sticks. And we didn't note any tendency to yaw which was mentioned here at forum recently.
Some things in controls seemed to us not very good but I'd rather discuss them with AAI first because they (things) are probably from our own gaps on assembly or may be from our different habits on controls.

We plan to continue testing so let's see further.

Cheers,

[Heron]

Very good Alex and big thanks!!! :D
You guys rock!
Heron

[ventana7]

Congratulations Alex!!

And a hearty THANK YOU for reporting your initial testing is such succient detail. Please continue to give us your test results as you progress.

Rob

[KenSandyEggo]

Alex, did you send your above post to Aero-News Network (Jim Campbell), or did he steal it from here?

[twistair]

Hi, Ken ;)

That was me - I use to send them Russian general aviation news time to time last years. Fortunately they brushed my clumsy English :o

[darrellwittke]

Say, If that is a 4-bladed rotor and not a trick of electronic photography, how did you clever chaps do the scissors hinge?

[Heather Poe]

Since most older (non- high definition) televisions alternate between even and odd scan (horizontal) lines, using each set of even (or odd) 60 times per second in an interleaved manner. I suspect that the rotor was in one position and then 1/60th of a second later in a different position. A complete picture takes 1/30th of a second, comprised of two 1/60th of a second interleaved (called interlaced) subpictures.

[Heather Poe]

The moving background looks like it was double exposed, just what you would expect when the two 1/60th of a second fields are used to create a 1/30th of a second frame.

[Jon B]

At 300 rpm that would be about 30 degress every 1/60 second. It appears to be in the neighborhood of 30 degrees, so that would probably confirm Heather's explanation. (Not that we needed it).