skippydiesel Posted June 18, 2020 Posted June 18, 2020 Anyone know where Robyn Austin's fantastic record breaking Rotax 912 ULS powered Soneai II is now? Cant find it on the VH register. This is the aircraft that all the fast glass aircraft makers dont seem to be able to match, let alone better.
FlyBoy1960 Posted June 19, 2020 Posted June 19, 2020 I will ask him tomorrow and see if he knows. I "thought" i heard it went to the USA some time back. Cheers
skippydiesel Posted June 19, 2020 Author Posted June 19, 2020 I will ask him tomorrow and see if he knows. I "thought" i heard it went to the USA some time back. Cheers That would be a shame
kgwilson Posted June 19, 2020 Posted June 19, 2020 I read something about this a year or 2 back. Don't know where but with all the streamlining etc I think the cruise was around 170 knots. Anyone know if that is correct.?
Thruster88 Posted June 19, 2020 Posted June 19, 2020 http://www.worldrecordplane.com/aircraft-development-story Sounds like it has RV performance with half the horsepower. I guess that is possible. 2
tillmanr Posted June 19, 2020 Posted June 19, 2020 The registration now appears to be allocated to a Cirrus
skippydiesel Posted June 19, 2020 Author Posted June 19, 2020 I read something about this a year or 2 back. Don't know where but with all the streamlining etc I think the cruise was around 170 knots. Anyone know if that is correct.? Try: Sonerai World Record Plane - Robin Austin for the facts from Robyn himself. http://www.worldrecordplane.com/aircraft-development-story Sounds like it has RV performance with half the horsepower. I guess that is possible. No need to speculate- check out the above , Sonerai World Record Plane - Robin Austin for the facts. Robyn Austin is one of aviation's unsung heroes - He takes a naturally aspirated Rotax 912 ULS (100 hp), puts it in a Sonerai II he builds himself and by applying fantastic attention to detail, good aviation engineering theory, end up with an aircraft that breaks a heap of Wold Records. I love comparing all the Rotax 912 powered, sexy looking, factory aircraft inflated performance claims, with his third party verified real life achievements - puts the "in your dreams" claims to shame every time. I have never seen VH-SGS in the flesh and now the Yanks have her I suppose I never will. 2
Flightrite Posted June 19, 2020 Posted June 19, 2020 Interesting read? For an A/C that looks rather basic/ordinary it sure is slippery? 1
flyvulcan Posted June 19, 2020 Posted June 19, 2020 Anyone know where Robyn Austin's fantastic record breaking Rotax 912 ULS powered Soneai II is now? Cant find it on the VH register. This is the aircraft that all the fast glass aircraft makers dont seem to be able to match, let alone better. Erm, the aircraft in my avatar is fitted with a Rotax 912 ULS and has a cruise of over 180ktas and a top speed of around 190ktas... It is waiting for an IFA prop to be fitted to expand that envelope a little more as it runs out of pitch at the top end with the current fixed pitch prop on it. I am currently having a new version being built that will be faster... The Jab3300 version is currently topping out at 201ktas. My 200hp turboprop version will top out at ? Full credit to Robin to achieve what he did with a Sonerai. 2 1
skippydiesel Posted June 19, 2020 Author Posted June 19, 2020 A Interesting read? For an A/C that looks rather basic/ordinary it sure is slippery? Would seem from the article that a lot of attention was paid to the cowling (in/out) and the rest of the air frame has just been built with very high attention to quality/detail, with, what sounds like, minor mods thrown in. What I cant understand is why the engineering that Robyn brought to VH-SGS, cant be applied by every aircraft supplier, at least in the more cross country cruiser type aircraft. SGS wasn't just fast she was extremely economical as well. There are only a very small number of 912 powered (or similar hp) aircraft that have anywhere near his Sonerai's (verified) performance the rest just look fast (all hype and no delivery).
Flightrite Posted June 20, 2020 Posted June 20, 2020 A Would seem from the article that a lot of attention was paid to the cowling (in/out) and the rest of the air frame has just been built with very high attention to quality/detail, with, what sounds like, minor mods thrown in. What I cant understand is why the engineering that Robyn brought to VH-SGS, cant be applied by every aircraft supplier, at least in the more cross country cruiser type aircraft. SGS wasn't just fast she was extremely economical as well. There are only a very small number of 912 powered (or similar hp) aircraft that have anywhere near his Sonerai's (verified) performance the rest just look fast (all hype and no delivery). Cost, mass production, clientele are just some of the reasons why manuafacturers stick to well proven affordable designs that they know the masses will purchase. If it where easy to achieve those numbers then we wouldn't be having this conversation. 1 1
skippydiesel Posted June 20, 2020 Author Posted June 20, 2020 Cost, mass production, clientele are just some of the reasons why manuafacturers stick to well proven affordable designs that they know the masses will purchase. If it where easy to achieve those numbers then we wouldn't be having this conversation. Maaate have you ever heard of plastic (composite) ? and I am of course referring to the host of "sexy" fast (not so) looking small aircraft (both composite & metal) that have come onto the market since Robyn Scott developed his Sonerai 2 and while I am on the topic, how come there isn't a Sonerai upgrade, to something like SGS capability, being marketed? Mr Scott did nothing extraordinary to his metal & fabric Sonerai, think how much easier/consistent it would be to do something similar in composite. To the best of my knowledge there are no "mass produced" aircraft - they are all essentially hand built, on a demand basis. My speculation - its cheaper to sell a story/marketing (to the gullible) than to develop a genuine high performance 100 hp aircraft and of course not everyone wants a fast cruiser.
Thruster88 Posted June 20, 2020 Posted June 20, 2020 Just speculation but SGS may not have been strong enough for the speed it achieved to be safe in the hands of average pilots. Stronger airframe more wieght lower performance, everything is a compromise. Skippy how close is your aircraft in terms of fuel efficiency to the record set by SGS?
skippydiesel Posted June 20, 2020 Author Posted June 20, 2020 Just speculation but SGS may not have been strong enough for the speed it achieved to be safe in the hands of average pilots. Stronger airframe more wieght lower performance, everything is a compromise. Skippy how close is your aircraft in terms of fuel efficiency to the record set by SGS? You are absolutely correct regarding structural integrity: "The green arc terminates at VNO, the maximum normal operating velocity or maximum structural cruising speed. The formula for calculating VNO is somewhat complex. But one of the formula's factors is the airplane's ability to withstand a specified vertical gust (30 feet per second for planes certificated before August 1969 and 50 feet per second after this date) and not exceed its maximum load limit. It's important to remember that VNO is a certification value. Only maneuvering speed (VA), which will be addressed shortly, will protect you from harm in turbulence. VNO is also the start of the yellow arc, often called the caution range. Flight in this speed range should only be considered when the air is glass-smooth because the slightest burble of air may cause you to exceed the aircraft's maximum load factor. The yellow arc terminates at the red line—VNE—the velocity that should never be exceeded. VNE is 90 percent or less of the demonstrated dive velocity (VD), a calculated value and/or the speed at which a test pilot flew the plane with no vibration or buffeting severe enough to result in structural damage. Don't think there's a 10-percent safety buffer past VNE. A baby's breath will cause the aircraft to exceed its limit load factor, and structural damage will result." AOPA I would point out though that the often ignored (by potential purchasers) aircraft specification VNE and the "buffer' between VNO actual/ max aircraft speed and VNE is an indicator of actual operational structural integrity. Aircraft with a narrow buffer might well be avoided. Many aircraft have very wide buffers where the aircraft can never hope to approach VNE in level flight . In short as pilots, we all have the potential to exceed VNE - just put your aircraft into a steep powered dive. In the end we take a risk when our feet leave the ground, it is up to us to respect the manufacturers calculated V speeds and our own limitations ie manage risk. Fuel Efficiency ?- I would have to read the story again but as my Zephyr is a much slower aircraft than SGS (using the same 912 engine without tuned exhaust, carefully engineered/plumbed custom cowling and CS prop) I would speculate we are not even close - If I remember Robin Scott speculated he could cross AU on 2 refuelling ?? 1
spacesailor Posted June 20, 2020 Posted June 20, 2020 At 61 mpg US. The old Hummel Aviation, hummelbird, would have been very frugal, only 140 mph vne, and one seater. But still a good performance !. spacesailor 3
skippydiesel Posted June 20, 2020 Author Posted June 20, 2020 Its interesting, at least to me, to speculate about aerodynamic "tweaking" that allows either the same air speed at a lower power/ fuel consumption/hr, higher speed for the same power setting/ fuel consumption/hr or even a higher speed, higher power / fuel consumption/hr that may result in the same or lower fuel consumption/trip. "In 2008, SGS competed successfully in the FAI Speed Over a Recognized Course World Record category, completing a 500 Km flight in 68 minutes at an average ground speed of 440 KPH (238 knots : 273MPH). One 200 Km section was covered in 25 minutes at an average ground speed of 467 KPH (252 Knots : 290MPH). The GPS flight logger confirmed ground speeds over 300 MPH at times. SGS also competed successfully in the Aeroplane Efficiency World Record category in 2 weight classes, the best result being a 1200 Km non-stop flight around a closed course using only 43 litres of fuel. That’s less than 7 LPH at 197 KPH (1.85 US GPH at 122 MPH). ( 7 L/h @ 106.4 N, in ground terms this is about 3.55 L/100 kilometres or 28 kilometres/L or in the very old units about 79.6 miles/gallon - about motorcycle consumption but at much higher speed) In all, four World Records were established, exceeding previous Speed and Efficiency benchmarks and remaining today as the best recorded flight performances in each weight category for any aeroplane type. As well as being a World Record performing aircraft, SGS is also aerobatic and a capable cross country 2 seat tourer. It has a demonstrated service ceiling of over 24,000 feet, can remain airborne for over 14 hrs and could fly across the entire mainland USA at its widest part with only one fuel stop." Robyn Austen I would be ecstatic if I could do 120 N at 14-16L/hr. I like 120 N (2 N/min) cause its a nice figure for mathematically challenged dills like myself to do a bit of in flight mental figuring. 1
facthunter Posted June 20, 2020 Posted June 20, 2020 (edited) Yes 120Kts 180 and 240 make calculations easier. Your maps are in NM's If you are going for speed your engines power should be just enough to do the job comfortably otherwise the engine is heavier and has a bigger cross sectional area . Both add to drag. Cooling can be a thrust enhancer. Fuel consumption is a factor in the in flight weight and it costs fuel to carry fuel. Small planes are more critical than larger ones with boundary layer control and fairings and surface accuracy enhanced. (Scale effect at play). If a design is operating above it's L/D best performance it can by being overpowered (Brute force) at a cost to efficiency You are also getting into envelopes where flutter becomes a serious matter and the structures aeroelasticity and how the controls are actuated and are damped, get important. Nev Edited June 20, 2020 by facthunter
Flightrite Posted June 20, 2020 Posted June 20, 2020 This is the one !. Only a mother could love that!???[ATTACH=full]54181[/ATTACH] spacesailor
cosmicray Posted June 21, 2020 Posted June 21, 2020 Its interesting, at least to me, to speculate about aerodynamic "tweaking" that allows either the same air speed at a lower power/ fuel consumption/hr, higher speed for the same power setting/ fuel consumption/hr or even a higher speed, higher power / fuel consumption/hr that may result in the same or lower fuel consumption/trip. The Sonerai has a very slippery airframe because it was designed for Formula Vee racing. I am getting 170 knot comfortable cruise in a Sonerai 1 with a Jabiru 3300. VNE for the Sonerai 1 is 195 knots. Full credit to Robin Austin for achieving the performance he did with a Sonerai 2 and less horsepower. In December 2019 John Monnett (designer of Sonerai and Sonex) announced that the Sonerai will be "coming home" and Sonex will be selling plans and parts. https://www.sonexaircraft.com/sonerai/
skippydiesel Posted June 21, 2020 Author Posted June 21, 2020 The Sonerai has a very slippery airframe because it was designed for Formula Vee racing. I am getting 170 knot comfortable cruise in a Sonerai 1 with a Jabiru 3300. VNE for the Sonerai 1 is 195 knots. Full credit to Robin Austin for achieving the performance he did with a Sonerai 2 and less horsepower. In December 2019 John Monnett (designer of Sonerai and Sonex) announced that the Sonerai will be "coming home" and Sonex will be selling plans and parts. https://www.sonexaircraft.com/sonerai/ 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?
Thruster88 Posted June 21, 2020 Posted June 21, 2020 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? This is a 2017 build registered to Robyn, I am curious, a new and improved version of SGS ?
skippydiesel Posted June 21, 2020 Author Posted June 21, 2020 Wow ! Awesome ! Front end looks a little different to SGS. What engine ?
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