VH - SGS Soneri II

[skippydiesel]

Found another photo of SRS - 2 blase prop, no wheel fairinfs and a good shot of gap seals in this pic

 

[skippydiesel]

Would be great to get Robyn to give us the story of this aircraft (SRS)

[ave8rr]

Robyn's first sonerai VH-SGS (now RAAUS registered) is here in Bundaberg. Has flown only a hand full of times in past 8 or 9 years.

[skippydiesel]

Robyn's first sonerai VH-SGS (now RAAUS registered) is here in Bundaberg. Has flown only a hand full of times in past 8 or 9 years.

 

That's verging on a crime - an aircraft like that should be flown regularly for all to appreciate. Would the owner consider parting with it ?

[cosmicray]

Hi Cosmicray

 

Out of interest - what fuel flow do you plan for when cruising at 170 knots?

 

Had a quick look - all modified VW powered - some vague mention of support for alternative engine(s). A person could be forgiven for wondering why Robyn Austen's concepts have not been adopted after all its still pretty much a plans built "kit", how hard could it be?

Not able to give a firm fuel consumption number because the original Bing carb was replaced by an Aeroinjector when the aircraft had done around 10 hours. Since then I have been fiddling with the tuning of the Aeroinjector. My estimate is 24 litres per hour at 170 knots. Flat out at 190 knots consumption would be around 35 litres per hour. Obviously Robin Austin has achieved some remarkable performance records but the Sonerai is already a fast design and if you add more horsepower then it will be faster. The really nice thing is low speed handling and landing is very easy and enjoyable. My engine mount is standard length and balance is as per plans because the Jabiru 3300 weighs about the same as some VW's and seems a good match for the airframe. Was interested to see that Robin built another Sonerai - he must know something!

[skippydiesel]

That's awesome fuel efficiency. keep us informed as you refine the tuning of the fuel delivery system.

 

If my maths isn't too rubbish, that works out at about 14 L/100 Nautical miles or about 7.6 L/100 km for an automotive equivalent..

 

Might be interesting to have an idea of your fuel consumption at say 120 knots.

[danny_galaga]

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[danny_galaga]

This is the one !.

 

 

[ATTACH type=full]54181[/ATTACH]

spacesailor

 

I think it's cute ?

[skippydiesel]

Robyn's first sonerai VH-SGS (now RAAUS registered) is here in Bundaberg. Has flown only a hand full of times in past 8 or 9 years.

Hi Ave8rr - any chance you might convey my interest in the original Robyn Austen Sonerai to its current owner ?? Never know he might jsut be interested in selling it. Nothing ventured. Nothing gained.

[R Austin]

Hi folks.

I’m not big on social media or forums but stumbled across this one where I see some curious interest in my project’s (thank you kindly for that), so I registered as a member to provide an update.

Yes, VH-SRS is an updated, larger and more capable version of VH-SGS.

I will undertake to provide a quick overview of this new (been flying nearly 3 years now - I’m getting slower with age ha ha) aircraft in the next couple of weeks. Will be away till then, but will take a current pic with new cowls, and (almost) finished paint. Looks a bit prettier now than in above 2018 and 2019 pics.

Cheers

Robin

[Flightrite]

Love the style of the Sonerai's, this is my fav, would love one of these?

[R Austin]

Love the style of the Sonerai's, this is my fav, would love one of these?

 

This looks like Jeff Lange’s plane at Oshkosh.

This is a really interesting and accomplished plane! Nice chap too. Very generous with his input to the sport and type.

Well worth reading up on if you can find his threads.

If anyone has a current contact for Jeff, I’d be really interested in touching base with him. He seems to have dropped out of the scene a few years ago.

Robin

[R Austin]

Hi folks. I undertook to provide an update on VH-SRS recently. To those who showed an interest, sorry about the delay, a family issue has preoccupied me in recent weeks. I will follow up as soon as I get a chance.

Regards Robin

[R Austin]

Hi. Here is the description of SRS that I promised. Apologies for the formatting. 

 

SERA-173 (VH SRS) is the 3^rd aircraft in my journey of developing evolutionary aircrafts originally based on the 1970 Monnett Sonerai II design.

The mission was to build the smallest most efficient 2 seat aircraft outside, with the biggest achievable cockpit inside. 
SRS is likely the first Rotax 912 aircraft capable of carrying 2 large adults whilst achieving genuine RV series performance. 

Although maintaining Sonerai heritage, SRS is considered sufficiently divergent from the original Sonerai design to warrant a new name, hence the SERA-173 (Stands for Sonerai -Evolution -Robin -Austin - 173 knots max cruise speed)

 

Broadly speaking the SERA 173 specs and differences from a standard Sonerai 2 are as follows (all solo)

• Max continuous cruise speed 173 Kts

• All day everyday cruise speed 165 Kts (24”/4800rpm)

• Economy cruise - 160 Kt at 15.2 L/hr 

• Aerobatic +6G -5G

• VNE 180Kts (testing included full range flutter testing up to and including 200Kts)

• 300Kg empty - 600KG MTOW – 300Kg payload 

• RV10 cockpit dimensions - comfortable for 6’5” pilot, 6’2” PAX (Sonerai volume +67%)

• Centreline flying from front seat

• High strength crash resistant zone around pilot (2.5X FAR23 requirements)

• Airframe structural strength = Sonerai +25%  

• Airframe efficiency = Sonerai +72%

• Stall speed slightly less than Sonerai II (minimum solo 39Kts)

• 1250 NM range at 160 Kts 

• 1700 NM range at 100 Kts 

• Also comfortable at 70 or 80 Kt “loitering” speed

• Constant speed propeller with latest Sensenich high speed blades

• 23” prop clearance for gravel strips

• Full span (30 degrees deployment) electric flaperons

• Horizontal Stabiliser - electric inflight adjustable

• Rotax 912 reliability and operating costs

   

  Although now flying for 150 hrs over 3 years, SRS is still “work in progress” hence the temporary SERA 168 logo (which was based on the target design cruise speed).           SRS also features 1-person-easy-folding wings to minimize hangar space requirements, or in this case negates the need for a hangar as its current home is a custom built, generous sized, air-conditioned enclosed trailer (See photos attached) which doubles as a hangar and workshop and lives right outside my garage (I can play with my toy anytime!).

The design, construct and refinement project (including trailer) has taken 8 (enjoyable) years and development continues.

 

Robin

[R Austin]

[R Austin]

The pics are a bit grainy. I compressed them too much. I’ll try again.

[R Austin]

Ok, too much resolution. Won’t open now. Sorry about the false starts, but it seems I can’t delete once posting.
1 last try. 

[R Austin]

Hi Lyle. Good to hear from you!

Yes, the wing fold is essentially as per original Sonerai plans, but I just refined it all the way through construction so that it is a genuine easy and fast 1 man job. 
I trailer it and set it up for each days flying. About 140 times so far. 
Keeps getting a bit quicker as I think of little refinements.

5 min to unload and 5 min to assemble and preflight. Quicker if I need to be.
Typically 10 minutes from arriving at the airfield till turning the key.

Might be a bit of a job retrofitting it to a finished aircraft though!
Cheers

Robin

[skippydiesel]

Robin, You are  genius par excellence. How is it that you can alone seem to be able to deliver such whole of aircraft efficiency, when the rest of the light aircraft world continues to squabble about the size of the engine or how "sexy" the aircraft looks.

 

Four questions:

 

• You have told us the prop blades are Sensenich - iI assume the hub is from a different supplier, are you at liberty to name them? (supplementary Q hydraulic or electric control/governor?).
• What might be your estimated ground role? and climb speed/rate?
• Rotax 912 enhancements ?
• Will you be supplying plans/kit/factory aircraft any time soon?

 

[R Austin]

Hi Skippydiesel.
Sorry, embarrassingly your name escapes me even though you’re my number 1 fan!

Thank you sincerely for that and the kind words you write.

I’ll let you know if I discover a number 2 ha ha.

Re prop... the blades are C65AY Sensenich. Hub and electric CSU, spinner etc are Airmaster. All commercially available and damn good stuff too. Very well engineered. All integrated by Airmaster as turn key product.

To be honest, can’t tell you min ground roll as I operate off gravel strip and am quite conservative with power application. Not stol but still quite short. From memory it’s well under 200m solo, but don’t hold me to it. 
I regularly take off and land on first half of 600m strip with minimal braking.
Wing section changes were intended for top end speed, but made biggest difference at bottom end. With flaperons, it only has to accelerate to 40 kts although I usually lift off at 50.

Initial stabilised climb is 1730 ft per min as tested solo at ISA. Less if hotter or higher. This is less than SGS as this plane is unavoidably 30 Kg heavier as it is larger and stronger. This is the only area it has less performance than SGS.

Motor is bog standard 912 ULS. Except altitude leaning provisions.

No plans or kits proposed. Too hard, too old, too lazy ha ha. Plus, the Chinese (or Nigerian scammers) would just steal all the IP. I’m not smart enough to protect myself!

hope that’s helpful.

cheers.

 

 

 

 

 

[skippydiesel]

Great stuff Robin

What amazes me is the performance of your creation. Its not just the speed,  its the econamy/range, the low stall -  the doing of so much more with less - very much the subtle sophisticated approach to aircraft design/power - as apposed to the just add a bigger donk & brick will fly philosophy.

I run the same engine, Rotax 912 ULS, in what most of my compatriots would consider to be a reasonably slippery airframe, ATEC Zephyr (Vne 143 knots Vso 30 knots).

We can achieve 120 knots, at sea level, but my ground adjustable prop runs out of thrust at that point (pitched too fine). I am exploring my prop options to try and maintain my absolutely essential short field performance (dodgy home strip) while opening up my cruise.

Seems to me a CS prop is my only option. I note that you have selected a 3 blade this time around ?

The " boys"  of the Forum most of whom appear to be lovers of low & slow, seem reluctant to offer much in the way of critical support .(See This Forum - Engines & props) So any advice will be most welcome.

I have contacted a number of CS prop suppliers, Airmaster amongst them. Airmasters response was fast & professional but has me feeling that their recommendation might be a little generic, in that there was no questions on either my aircraft or my goals for it -  I have asked for their recommendation rational - we will see.

Got to go! granddaughter demands!

[skippydiesel]

Great idea! Hope something comes of it.

[R Austin]

I spoke to Mr Monnett senior and junior at Oshkosh in 2011. Not specifically on that specific idea, but I did offer to get involved with the onex in a drag reduction role. They seemed little interested so I left it at that.
It’s not unusual for designers over the years to seem perhaps quietly offended by others messing with their design. 
I detected that may have been the case here, but couldn’t be sure.

 

 

 

[R Austin]

Hi skippydiesel and anyone else interested.

That sounds bad, can I ask your first name please?

i will respond to your prop question soon. 
Also. Thought you may be interested, I’m having a parallel conversation on the Sonerai.net site under “world record plane 12 years on” covering similar subject matter if you wish to tune in.

cheers

Robin

[skippydiesel]

Too bad about the Monnett family attitude - If the Sonerai does not evolve, it will ultimately disappear from the sky and become a footnote in the history of small aircraft aviation. I will certainly "check out" the Sonerai Forum