Hi!
I have almost finished my Tucano, but mine comes out way heavier than the manual says. The manual says 4200 kilogram, but my is 6000kilogram (ready to take off) A great deal of accsessories on this one[&:]
I have a OS 108 two stroke engine behotec retracts and glassed wings(light).
the wing loading should be 97grams/dm2 but mine is 139 grams/dm2(46,33 oz/in)
I have calculated the stall speed to be 25 MPH, but this is pretty rough measured.

Any thoughts?
Will i be able to land this plane under supersonic speed?
is it any hope?

Would not be the first plane that Nitroplanes.com has got the weight wrong in the manual, or the CG either. Maybe PM one of the people here for help as they have flow this plane http://www.rcuniverse.com/forum/m_72...tm.htm#7246493

My Nitroplanes Bobcat has both the WEIGHT and the CG stated WRONG in the manual.

I have tried to PM different ones, but have not received any answers yet[] I'll keep trying.
I have more than once experienced that the stated weight has been higher than the manual says.
I guess the main reason why this plane is extra heavy is my own fault. I have added behotec c 36 air retracts with pneumatic brakes, light system and bomb drop.[8D] the others I have seen in different threads has been about the right weight

Of course,,Adding all those gooddies will up the weight! And I doubt you'll find any help from Nitro on this. Not likely anyone has flight tested the same setup. If 25mph is the estimated stall speed I'd look at mixing in flaperons. This might reduce your stall and 25 is not a horrible stall speed for a decent piolt. Beside what else ya gonna do unfigerglass the wing???

No I was suspecting it was little Nitro could help me with. Just hoped they have heard about someone else with higher weight than stated on this plane, and could share the info.
The estimated stall speed is not giving me nightmares, but it seems to low to me. This model has split flaps, so I guess I could get the landing speed down but if it's too heavy I need the speed to keep the plane airborne during the landing. I am experienced, but I don't like to land fast planes with over half throttle. I don't think i'm De-glassing the wings.
Someone said that every landing is a controlled crash.
I say: INCOMIING!![&:]

Are you sure your loading calculations are correct?

I find that most RC models will sustain a 33% weight increase or more without doing too much damage to the flight charactersitics.

As a result I often load down my planes with large 3800mAh NiCD or NiMH batteries to give me long flight times and better wind penetration.

46oz/in is analogous to a loaded warbird.

The Tucano's straight wings will help prevent uncommanded snaps, so from your perspective all you may see is a need to maintain some throttle on landing and faster speeds than what you are used to.

I hope you have at the very least a 500' runway available.... I have a few planes that take the full 500' to come to a stop, and even then need a bit of left and right goosing of the rudder to get them to slow down.

Thanks for the reply and the encourage.
I think that my calculations are correct, but I have done some bad calculations before so I'll never know you know[8D]
That calculation of the stall speed was just something I found on the web. (3.7 * SQRT(weight/wing area) (ft2 & oz)
You mention that 33% weight increase and then some is OK. My tucano is about 43% overweight.
For the first flights I will have a little over 2600 feet of runway, and the tucano has pneumatic wheelbrakes as well so I hope that I should get it to stop somewhere on that runway
I like it when my planes starts to descend when I reduce throttle and not when they are light and "ballooning" around., but I have never had a plane this far out on one side of the weight scale.

I pushed your numbers though Motorcalc and I come up with a 35mph stall speed.

This seems more accurate to me than the 25mph speed.

Thank's! I agree that 35mph seems more acurate.
I will hopefully have done the maiden between 21-24 mai. i'll let you know how it passed that test

The maiden is done!
This plane turned out to be my one and only favorite.
It has, believe it or not a nice slow landing speed
Without flaps deployed it has relatively high landing speed, With low flap setting it is nice predictable and slow.
With full flap setting it is almost hard to get down[&:]

The first takeoff went through with no input of elevator. It has to have some down elevator trimmed in to fly straight.
It also had a three blade 16*8 prop. This was OK, but it did not have the speed i had hoped for. I had the idle set too low which resulted in a bit hard dead stick landing.

The second flight was with a 16*10 two blade prop. This gave the high speed i was hoping for.
the landing went through with low flaps setting.

here is the video of the maiden flight:
http://www.youtube.com/watch?v=UOpBdoEcW4Q

I love this plane!!!!

Nice!

The landing looked about right... 34mph or so, not a problem though.

Did you configure it with drop tanks?

I bought a pair of bombs with included drop mechanism. These came with a pair of extra fasteners. Not scale, but fun anyway
The extra fasteners can be used to make drop tanks or as i will do. make the included machine guns detachable for low drag and high speed, or with the guns mounted for display.
The picture shows the bombs just released. The bombs was released in lower speed than those in the video. The smoke trail is from cocoa powder

.