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It is true...


Tomo

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Ok, so we've all heard Cameron and Slarti go on about these Morgan contraptions... and I've always just thought - "Oh yeah, it's just another aircraft" and never really gave it much thought. Saw them at Temora etc... Pretty cool I spose, and that is about as far as it got.

 

Well I got talking to Gary Morgan, and had a bit of a look at his Blue Sierra 100 up at Monto. Looks great I thought, removable wings... that's pretty handy. 130kt cruise... "Wha...?!" I was amazed at that... pretty good! "So what sort of stall speed are we talking?" I asked - thinking somewhere along the lines of 40 odd kts. "20kts" he said... Wow! My jaw was getting a little lower each time.

 

I left and went and caught up with some others, and checked out some other aircraft, but just couldn't get that Sierra out of my head. I'm gonna have to have a fly of that I said to myself. So back over to him and few more pictures, and Tim was pretty busy taking others for a fly as well. So once he landed and taxied up again, I asked him "enough fuel for another?" "Yep" came the reply... so I bundled in, and - could have stayed there. Could have just been the fact I had done 3hrs of speed skating the night before, then standing around most of the day. But I don't think so.

 

Four point harness was soon doing it's job, and the 3300 fired up. Taxied out using toe brakes for steering at slower speeds. Lined up and away we go... 80kt climb out at 1000fpm! Soon clear of the circuit and sufficient height put it on a 60 deg bank, power back, stick back...speed... what speed?! just sat there! that is so stable! Flap back up, cruise S/L huge amounts of view out the front, out the side... even down - for a low wing, I was amazed.

 

Cranked it up a bit for a fast x wind joining of the cct, 140kts, with power to spare, S/L You had to be careful not to exceed Vne, I mean that's incredible!

 

To sum it up, I've flown a few types of aircraft now - not enough, but this one instantly hit the spot for me, handling characteristics were fabulous at both speed ranges.

 

Can turn on the spot, differential brakes with a free wheeling nose wheel. Wings can be removed for trailering/hangering. Great comfort, easy to get in and out for a low wing.

 

Just check out this page before I run out of breath, A kit with 3300 engine is only $58k I mean.... 040_nerd.gif.a6a4f823734c8b20ed33654968aaa347.gif :thumb_up:

 

Ok, I'll stop now and just show you some photos of the Blue Sierra 100 -

 

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Good report Tomo, thanks for posting it.

 

What a great looking aircraft, and the performance is almost unbelievable at both ends of the performance envelope.

 

I really need to see a claivoyant for next weeks Lotto numbers 091_help.gif.c9d9d46309e7eda87084010b3a256229.gif, but I get disallusioned when they ask what your name is :confused:

 

 

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Hi David,

 

The factory specs quote a stall of 20knots with flaps.

 

With plenty of fuel in the tanks and two beefy POB, I would imagine makes quite a difference to the figures.

 

It would be interesting to know what the fuel and aircraft load was, when they arrive at the figures quoted.

 

Never the less, they look a very desirable little aircraft.

 

Regards

 

Planey

 

 

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I don't want to put a damper on this discussion at all boys and girls and I will add that these aircraft are getting great reports, but I have a real problem with an unqualified claimed stall speed of 20 knots, and it is not the first time I have seen that figure quoted on this site. Anyone who has been around aircraft knows that is definitely STOL territory and bloody good STOL territory. But most of us know STOL comes typically at the cost of cruise speed, yet here we have an example of numbers that may indicate some kind of super wing.....So some basic questions:

 

Is the 20 knots stall at MTOW which it should be or it should not be quoted?

 

Is that with the flap equipped model?

 

Is the 20 Kts IAS (indicated airspeed) or CAS (corrected airspeed) because there can be a significant difference at those low speeds?

 

David

Perhaps Slarti can shed some light on this?

 

 

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But most of us know STOL comes typically at the cost of cruise speed, yet here we have an example of numbers that may indicate some kind of super wing.....So some basic questions:

 

Is the 20 knots stall at MTOW which it should be or it should not be quoted?

 

Is that with the flap equipped model?

 

Is the 20 Kts IAS (indicated airspeed) or CAS (corrected airspeed) because there can be a significant difference at those low speeds?

 

David

One thing you have to consider in this sort of aircraft is - 544kg is MTOW, empty is 313kg. So it's not a lot of difference, as in, you'll be operating near the MTOW most of the time.

 

At this stage the aircraft should be fully certified, factory built for training applications in a few more months he said. So more accurate performance data will probably be available then.

 

But yes, it all seems a little unreal, that is why you have to take it for a fly, it is pretty amazing. You don't need to use your rudders much either, I rolled it from 45* one way to the other without rudder input, and it rolled on its nose as if you had use it. I wasn't being gentle either, it's no doubt an extremely stable aircraft.

 

One thing I will add also - its 20kts stall may make it a STOL aircraft, but You'd have difficulty dropping in over the trees to plant it down like that. With a 12:1 glide or better it's a pretty flat approach, if you can see what I mean. It may work at a steeper approach, but you may need reverse thrust to keep the speed under control!

 

 

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Fly it

 

I have to agree with you Thommo, amazing little aircraft infact far better than I had ever anticipated. The low stall speed and handling was very......very impressive. Thats my boof head in your first 2 photos, 190 cms and 105 kgs in perfect comfort. And with Tims first flight pretty close to MTOW.

 

To any one one who doubts the some claims made here in this thread......fly it!

 

This is a well built, sweet handling, pretty little aircraft and would have to be the best bang for your buck on the market.:thumb_up:

 

The only problem i had with plane was the spanner its thrown in my my financial works.

 

 

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Guest Baphomet

I'm another who has real problems reconciling the numbers. The site quotes 180mtrs landing roll. You don't need 180 mtrs if stall is 20knts!! If the numbers are real, then Gary has been able to achieve in his back yard, what multi-million/billion dollar corporations haven't been able to do with open-ended budgets and wind tunnels in 100 years.

 

Baph

 

 

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WOW guys, what a aircraft i have just read all the posts, 20 knot stall speed with flaps, thats unbelievable.The Savage cub crusier with VG,s, stalls at 30 knots full flap.These a/c will be rolling out the door, once the secrets out . 20 knot stall, 130 knot cruise (i think havent checked the web site yet). That speed range, without the use of Leading Edge fixed or retractable Slats, or VGs , has it got fowler flaps ?That must be a superwing.

 

 

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Guest Maj Millard

Good stuff Tomo, I've liked the Cheetah from the first time I saw one. I had every intention of dropping into the factory at Taree recently when I was there, but our own Pylon 500 came along and stole me instead. Flaps do work of course, however I not sure I'd want to go anywhere near 20 kts on short final if it was windy or knocky. Always better with a few knots up ones' sleeve as Motz found out recently. Hey that looks like my Townsville mate Steve sitting in the damn thing also !!...Great looking little wing, and it must work well also by the sound of it .........................................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

 

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Is there a "story" Blackrod?

 

Personally I think the product is bloody great! I hope that Garry and his son can get past the initial stages of setting up. This aircraft has every potential to be a star in the recreational flying arena. Lets hope that Garry can get it into certified production.

 

 

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Guest Maj Millard

Tarees' a great spot for aircraft manufacturing. The hangar looked good. Pity I didn't get a chance to look inside, as I was too busy, but it's a great excuse for another long flight !!..................................................................................................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

 

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Verify.

 

The figure is quite incredible and should be verified by GPS, or timed over a distance in a known or nil wind. There could be a substantial instrument error IF you are only relying the Airspeed readings. Where are the static ports and pitot head, located?

 

IF the cabin is the source for static or there is venting allowing that pressure to register, you will get over-reading at the top end and under-reading at the slow end. Likewise incorrect location of the static ports can produce an error either way, depending whether the pressure is increased or reduced.

 

With these figures out in the public arena there is a need for ASSURANCE.

 

MANY published figures quoted are very wrong for this reason. This is the main basis for skepticism, and it is across the ultralight industry. I infer no deception in THIS case, just emphasise the need to verify/authenticate the claim

 

Incidentally the "stated" stall speed is demonstrated with the aeroplane in a specified configuration . ( Usually engine at idle , and flaps full down (with Up, (clean) stated as well) at MAX weight and with the CofG in the most forward position attainable/permitted... Nev.

 

 

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The website does claim stalls of 30 knots clean and 20 kts with flaps. I understand the reason why some very experienced flyers here doubt the credibility of these numbers.

I had similar doubts at first... but it's a bit hard to argue when you go and do it, and it does it 040_nerd.gif.a6a4f823734c8b20ed33654968aaa347.gif

 

Another important aspect of aircraft purchase is the financial viability of the manufacturer - especially in these GFC troubled times - and their ability and desire to back an aircraft for 10 or 20 years..

Very good point, and it's definitely one of my strong points to a product also. Being able to install just about any engine type you fancy - that leaves that covered.

 

Made out of metal, and or fabric covered in the case of certain models - means anyone in that trade can work on them. Myself as a Mechanical Engineer was impressed, It is simple, efficient and performs with unbelievable results.

 

If you look carefully at the wing design, I think he's got a good recipe. And if he was winning model design awards at the age of 13, he's certainly got some trick to it.

 

:thumb_up:

 

Btw: He builds his own propellers... And if you put one on a Jabiru, supposedly it increases the speed by 5kts - go figure ;)

 

 

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MANY published figures quoted are very wrong for this reason. This is the main basis for skepticism, and it is across the ultralight industry. I infer no deception in THIS case, just emphasise the need to verify/authenticate the claim

I've asked Gary for clarity re your questions Nev. Not sure where the static is from, but the Pitot is under the wing, as you can see in the photos.

 

Truth be told, even if it stalled at 45kts, I'd still like it. In a tail drager config... that'd look so sweet.

 

 

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I will say that from on the ground the blue Sierra was certainly seemed amongst the fastest and most high performance aircraft in attendance. Very impressive... I would not doubt its top speed performance... its scoots!!!

 

 

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Terms and definitions.

 

I don't want to seem picky but you have to be very careful with the sort of facts that we are considering here. The wing stalls at a certain ANGLE (usually about 16 degrees) to the relative airflow. That's it. The RIGGERS angle of attack is decided by the designer and is the angle which the wing is fixed relative to the fore and aft axis of the fuselage. This determines what angle the fuselage will present when flying along at various speeds. With the wing fixed as Gary has done, it should result in the nose being quite low at high speed and lower than it would have been (with a more "normal" Rigging AoA.) at ALL flying speeds. This would improve visibility over the nose, which is quite long. While there would be some drag consequences with this, I would suggest that they would have nothing to do with stall speed in level flight. You would just get to THAT speed a little quicker, if we have more drag, and more slowly if we have less. We have to again remind ourselves that it is really an ANGLE that we have got to get to, and it's only the wing meeting the RELATIVE airflow to be considered. The plane is attached to it and goes along for the ride. Nev

 

 

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Guest ozzie

The wing stall is AOA to the relative airflow but the speed is PROPORTIONAL to WING LOADING. The wing section and type will also play a large part in the performance. An aircraft with a reasonably high speed will need a lot more than just flaps to get the speed down while still having a reasonable sink rate.

 

i think that if you put the pitot well away from the airframe in clean air with a calibrated ASI and do the test outside of ground effect you may find the real indicated stall speed to be quite a few knots higher.

 

 

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I don't want to seem picky but you have to be very careful with the sort of facts that we are considering here. ===

 

We have to again remind ourselves that it is really an ANGLE that we have got to get to, and it's only the wing meeting the RELATIVE airflow to be considered. The plane is attached to it and goes along for the ride. Nev

Not at all Nev, it's hard to explain, and is unbelievable - one of the reasons I just had to go and check it out. From what I studied/experienced from the maneuvers, it just does it - somehow.

 

Angles - that is right, not sure if it's relevant, but have you considered the fuselage? You have 42" of aerodynamic "lower" AoA surface there.

 

So the fuselage could be giving a bit of lift, thus lowering the "wing loading" thus a lower speed could be obtained?

 

The view out the front is terrific in cruise, funny actually, cause you can hardly see your nose.

 

 

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Lets just leave the guessing until hopefully in a few months time Garry and Son have the factory and structural engineer certified aircraft ready to go.

 

Wouldn't want to harm their chances by creating too much fuss over the factory claims... remember at the moment Garry is only selling an experimental kit aircraft. The final performance figures are relative to the build some what.

 

 

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Guest Baphomet

OK, this getting silly "it just does it - somehow". There is no magic in this, we are talking about well understood principals of physics. As Ozzi pointed out, stall SPEED is proportional to wing loading, i.e. for wings of similar area, the main factor affecting stall speed is WEIGHT. If the damn thing was made out of balsa wood you may get some low numbers. Take a look at the Joey MKII on Gary's site, similar design, 27kg heavier, same wing area (1 sq ft diff) stall of 40knts (clean) . Or the Cheetah, 53kg lighter, same wing area, stall of 30knts (clean). Those figures I can believe. We need to know what the configuration of the aircraft was when those numbers were generated. My guess of the real numbers, based on the published data of his other aircraft, would be a clean stall of 32 - 34knts and 28 -30knts with flaps.

 

Baph

 

 

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OK, this getting silly "it just does it - somehow". There is no magic in this, we are talking about well understood principals of physics. As Ozzi pointed out, stall SPEED is proportional to wing loading, i.e. for wings of similar area, the main factor affecting stall speed is WEIGHT. If the damn thing was made out of balsa wood you may get some low numbers. Take a look at the Joey MKII on Gary's site, similar design, 27kg heavier, same wing area (1 sq ft diff) stall of 40knts (clean) . Or the Cheetah, 53kg lighter, same wing area, stall of 30knts (clean). Those figures I can believe. We need to know what the configuration of the aircraft was when those numbers were generated. My guess of the real numbers, based on the published data of his other aircraft, would be a clean stall of 32 - 34knts and 28 -30knts with flaps.Baph

And that is exactly the numbers stated in the factory brochure Garry gave me on the weekend...

 

 

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Tom, I think the key to the matter is in Nev's first post, there can be quite significant errors in IAS. It doesn't really matter for practical purposes, as long as it remains consistent ie at a given weight and CG the plane always stalls at an IAS of 22 or 44kts for that matter. You will calculate your approach speed accordingly and all will be well.

 

You aren't the first and doubtless won't be the last to be deceived by this, but short of retractable leading edge slats and multiple section flaps (a la airliner) that sort of speedrange just isn't credible. I'd go so far as to say it is up there with magic 150mpg carburettors and the like and at the end of the day might actually be doing a great little aircraft a disservice.

 

 

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