hookemut

My Feedback: (3)

Hi Tinman, and others,
Have now accumulated around a dozen landings-no landing gear problems, no busted prop, in fact, no problems. The YS-140 with the Zinger 20x6 prop and the Slimline muffler is turning 7,000 rpm and flys the model beautifully. As you can see, it is very distinctive in the air.

However this model has a high wing loading which must be factored into landings.Our Stinson weighs 22 lbs or 353 oz and I calculate the wing area (no fuse) at 1,236 sq in or 8.58 sq ft. Therefore the wing loading at 353/8.58 is 41.7! For me, I don't cut power 'till I'm all set up to touch down and ready to land!

The nose has pronounced drop in a tight turns, so be alert. It is very responsive to all control inputs, especially rudder. We haven't got our flaps working quite to our satisfaction as yet-we feel that they will be a real assist.

Best wishes to all-GOD BLESS AMERICA!
Jim

tinman

My Feedback: (13)

looks great jim... ....am still doing finishing touches on mine but it should be ready very soon...will post when it is....-Tinman-

phoon

Gentlemen,

Thanks for relaying your experiences flying the Reliant. I'm trying to master the plane in the Real Flight Simulator, and it flies EXACTLY as Jim describes. I have to maintain some power and speed 'till the last moment to get the plane to track ahead properly on landing. Otherwise, if I am landing too slow, and try to stall it in, I end up with a floppy landing, with the wings sometimes touching ground in a reciprocal flop on one side, then the other, style. This doesn't happen if I maintain speed on my landings.

On the simulator, flaps are a mixed blessing. I haven't yet got the correct amount of elevator correction dialed in when flaps are extended, because the plane balloons upward as soon as I extend them in flight. I'll soon be adding my own JR 8103 radio, so I can refine the correction. I end up playing a trim game, which I can't win: Add down trim when the flaps are extended, and then I have to change back when the flaps are put back. When flaps are fully extended, The plane floats but picks up too much speed on the decent. I often come in too fast for the extended flaps case, and can't get the plane down, and overshoot the runway. Have you, Jim, had this happen in the real world?

Anyway, getting the plane to land where I want it to, has been a bear.


I think my best landings have occurred when I extend about half flaps, not full. I'm in less danger of stalling and executing the flip- flop style I described above with wings touching. I've found it is better to come in a bit faster than you want, than to come in slow, and try to stall in at the last minute. Stalling on to the runway is not a good idea with the Reliant.

I've thought of building this plane, but flying it in the simulator, tells me that something isn't right with this plane. I note that the Real Flight specs show the plane at close to 38 oz per Sq foot, very close to Jim's wing loading. Why does this plane build so heavy? I might consider building one, but only if I can get the wing loading down.

I am thinking of lightening holes in the wing, or the tail section. What could I do to build a lighter plane? I'm thinking a light plastic covering, Monokote, instead of the fabric I'd like to use. I'm thinking of my YS 120 AC instead of a twin, to have reasonable power, but to keep the plane lighter. I'd rather have a slightly underpowered but lighter plane.

I note that I can experiment and edit the specs that Real Flight put into the simulator, and change this baby. I'd like to see the wing loading down to around 22 to 26 Oz. per Sq Foot. Think that is possible?

I'd especially like to get ideas on how to build this plane lighter, before covering and engine installation.

My best gentlemen,

Peter

hookemut

My Feedback: (3)

Hi Peter,
What a very interesting post that you made! I'm really very interested at your similarity findings!
Attached is a pic of a French Stinson SR-10 landing. Note the full flaps and very attentive pilot!
Don't try to full-stall this puppy-a fairly hot wheels landing works best. Try to touch down at the very downwind edge of the runway. Ours is flown using a JR computer radio, so flap activation is coupled into elevator, with some down trim added when flaps are lowered. I have a scratch-built 105 inch version of the Stinson 10A Voyager and have very successfully worked out flap operation on this model. However, the wing loading is about 2/3 that of the SR-9!! A big rectangular wing.
I think that a wing loading that you indicated would significantly ease the landing effort. Getting there will be a challenge with the TopFlite kit. Going to film covering will definately help, as will no on-board glow driver and light weight servos-since this is not a 3-D flyer, small servos should be ok. Your YS-120 should be ok, we fly ours with a YS-140 and have really excess power. BTW, the side-saddle tank works fine. Very little weight saving by lightening holes in the wings-already 'holey'! As for the tail feathers, they are just light balsa sticks already. The substitution of fiberglas for the kit-supplied ABS plastic added weight. I believe that Pettit built his for around 17 pounds, which would give you a wing loading around 30.
You have an interesting challenge, I wish you the best. Write at any time, ok?
Regards,
Jim
[email protected]

phoon

Jim,

I thought of responding directly to your e-mail address, but I decided to keep the dialogue public, so other SR-9 flyers/builders could join in if they wanted to.

Jim, let me just say it is indeed a pleasure to have a dialogue between the actual builder and flyer of an SR-9, and me, the G2 simulator pilot/experimenter. I sure wish you could be right here at my 21 inch View Sonic monitor, in Nederland Colorado, and fly the SR-9 with me! And I'd like to join you at the field and watch you fly the "real" SR-9.

I thought that the G2 would help me become a better pilot. What I am now beginning to realize is that it can be more than that. What has surprised me, is that your description (and Petit's) of the flying characteristics of your SR-9, precisely duplicate what I am experiencing when I fly the SR-9 in the G2 simulator. The match is uncanny.

I bought the best video card I could buy (GForce 4 128 DDR TI 4600) and after some tweaking and trial and error, have a faithful simulation of the SR-9. I rationalized the expensive video card, with Barbara, by setting up a DVD CD ROM player in this 600 Mhz 256 MB PII, and Barbara and I switched to watching DVD CD movies, instead of the old video tapes. The subtitles help me since I am hearing impaired.

I'd be curious: Petit used 21st Century Fabric, and installed a OS FT 150 Twin, and substituted a Fiberglass Specialists cowl, wheel pants and fairings. He had JHM Engineering DGA-2 on board Glo ligher. His plane came in at 20 Lbs 3 Oz, with a wing loading of 30.62 Oz/Sq foot. This sounds wrong; it's too light with all this stuff.

The first thing I'd like to do, is be sure my SR-9 in the simulator has accurate specs. The flight character of the plane in the simulator can be precisely defined by placing into the simulator, accurate plane specs including (not exclusively) those which follow.

Wonder if you could correct or suggest changes for the specs I currently have in the G2 simulator for the SR-9?

I'd like to end up flying a plane exactly like the one your are flying.

The default SR-9 in the G2 Simulator is hearvier than Petit's plane:

The fuse weighs 15 Lbs
Wing 6.5 Lbs
Eng + Prop 2.47 (Brison 2.4 with a 20X10 prop)
Fuel 1.00

Total dry is 23.97
Total wet is 24.97
Wing Loading dry is 38.1
Wing Loading wet is 39.7

I think these wing loadings are close to what you are flying.

In the G2 Simulator, wing area is 1448, whereas Petit claims it is 1519.

This is not a big discrepancy, but I'd like to get an accurate number. Which do you think is the accurate wing area?

Well, I'm assuming all the other specs in the simulator are accurate, and the same as your SR-9. They include such things as size and weight of the rudder and elevator, and CG and landing gear spread (to simulate ground handling).

How much weight savings would be possible if I were to go with the kit's ABS parts, instead of Fibre-glass?

I think the YS 120 AC comes in around 35 Oz, so there is a weight savings possible on the engine. What does your YS 140 weigh with the muffler and prop? The G2 will alow me to substitute an OS 120 with an 18-6 prop, instead of the Brison, so it will be close to your YS 140, but not exact. Your YS 140 is a more powerful engine that the G2 available OS 120, and has a better power to weight ratio.

Can you help me find the specs for UltraKote vs. 21st century? I can't find the Oz/Sq Foot specs anywhere on the web sites for these products. Can easily compute the weight savings if I go to plastic instead of fabric, if I have these specs.

Well, the upshot of all this is to put in an edited version of the SR-9 into G2 that first, exactly duplicates your current flying model, and then, try a lighter version with plastic covering, a YS 120 AC, no glow driver, and ABS parts, to see if the two planes fly differently in the simulator. If this is getting too obsessive, let me know, and I'll cool it!

My best to you, Jim,

Peter in Nederland Colorado, at 9000 feet above sea level.

GaSeminole

Dont know if this is the right thread to address this question but since its about the stinson and the kit has all that ABS (if used), I heard the ABS cracks in time. Is this true of ABS and how long does it take?