After spending many hours on building this beast it will not FLY! (two flights and two near crashes).The CG is dead on for the battery used and controls are set to the low rate. I'm using a 12x8 prop and all the plane wants to do is climb. Several club members have checked the plane over as see no problems. The kit was short several parts and there were two mod notices with the kit. I've called Horizon Hobby three times and all these people seem to want to do is argue rather that help solve the problem.
Any help would be appreciated.
Ron

Check the incidence on the wings. (The bottom wing should be 0 (zero) and the top wing should be -1 (negative one) degrees. ) They are calling for them to both be parallel to the elevator (page 14), but it sounds like you may need to adjust that a little. . Also make sure you are CG'ing it on the TOP WING

Per the manual:
"The recommended Center of Gravity (CG) location for the Pitts
Model 12 15e ARF is 3 3/4– 4 1/8-inch (95–105mm) back from
the leading edge of the top wing"

Please let everyone know how this turns out. I have the same plane with the same power/prop that I am wrapping up (hopefully this week). What battery and ESC are you using? I'm using an E-Flite 60A Brushless Pro and planning on a 14.8V 4000mah battery.

Gotsky,
Like the name and thanks for the input. The incident of 1deg or so might be the trick. The CG is 3.75 just as called for in the manual which makes little or no difference of how the plane flys (nose up, plane will not level regardless of elev). Also there is no accounting for prop factor by tilting the motor several degrees down or to the right as in most designs. This is something else I need to try. The ESC is the E-flite 60 and the battery is an electrfly 3 cell 3200 pushed all the way forward and over the motor.

As mentioned in the second attempt to fly the prop was increased to a 12x8 from a 12x6. According to tech support at Horizon this is the problem and I need to use a 14" prop. Going from the 12x6 to 12x8 just made things worse.
Ron

Gotsky,
I assume you mean the -1 deg is that that the leading edge of the top wing is lowered correct? Also is this common for the bi-planes?
Do you have a Pitts or were you picking the manual off the web site?
Thanks..Ron

Prop the rear of the plane up so it's sitting level, and sight the wings from the side. For the issue to be this severe, you should be able to detect one of the wings is way higher in the front than in the rear. It's probably the top wing.

It's possible you put the cabane and interplane struts in backwards, which would raise the front of the top wing and lower the rear of the top wing.

Flyermark,
Did you get your pitts together yet?
I'm still having problems with mine and no help from Horizon Hobby(E-flite).
Just be careful with the power. The 25 motor has way to much power. A 3s Lipo battery is plenty for this plane.
Let me know how you make out....Ron

Matt,
I did try leveling of the plane and the wings are parallel. I did however put at least a 1 deg neg on the top wing. Nothing is off from the instructions of E-flite and surely not that far that it would be missed. At this point I'm of the belief that there is something very wrong with the design or at least with this particular kit.

The manual is based on the E-flite 15e motor and 4s lipo. The option for the 25 motor with 3s lipo is only mentioned as an option and not discussed as far as it is 7 ounces heaver than the 15e combo. I have tried both weight options and had to add LOTS of weight to the tail to get the 3.75 in CG. This still doesn't make much sense because my plane flies like it's tail heavy
I did discuss this with Horizon tech and their answer was " adjust you elevator linkage? (i currently have 1.25 inch throws as it is).
Thanks...Ron

If this plane is over powered with the 25 I wonder whats going to happen when I finally get mine in the air with a Rimfire 35-48-1000. It seemed like a good idea when I ordered it.

http://www3.towerhobbies.com/cgi-bin...&I=LXLWU8&P=SM

I have not gotten mine in the air yet but it is ready for that. I had no issues balancing mine at 3 7/8" CG with the Power 25 and 2 3S 2200mAh batteries. No added tail weight required. (Rudder and Elevator servos are HS225BB).

One item I did note when I did check the manual was that you must ensure your measurement is from the "flat" portion of the top wing (center - above the fuselage). I had to stop for a second when the plane was sitting on my balancer set to 3 7/8" and the vertical pins didn't touch the leading edge of the wing. (It is a great planes balancer I just bought vs. the two finger approach). Maybe something I should have anticipated but I haven't been in the hobby that long. (12 mos which includes our nice Michigan winter months.)

My work schedule is crazy (good thing in this economy) so I will probably be next week before I get the test flight done. I looking forward to it but will be cautious given this posting. I am hopeful it will be as much fun as my GP Yak-54 EP which is an absolute blast to fly.

Ok. Admittedly unplanned I was able to get and impromptu maiden flight today.

I fly only on grass. I was doing ground checks and taxi checks on our field and was having some nose over issues while doing my slow runs. Too little speed and our grass pot holes will do that. Not a big deal. To compensate I just fed in full up elevator and increased the speed a bit. Pretty good results so I decided to make a high speed run with full intention of shutting he down and bringing her around again.

While that was all I intended she went airborne midway through the run. [:-] That is my rookie experience showing through - holding a bit too much elevator. I'm pleased to report there were no major issues. I had to put in 6 - 8 clicks of up elevator indicating my CG is a little too far forward with the final placement of the battery but nothing major. No other issues. Flies nice and lands nice but I kept it simple and short tonight.

The Power 25 is not too much power with the 11.1V lipos.

Plane Summary
Motor: Power 25
ESC: Brushless Pro 60A from E-flite
Battery: 2 11.V 2200 mAh to get 11.1V 4400 mAh total (they fit nicely directly under the battery hatch. Nothing over the motor)
Prop: APC 12x8E
All servos are Hitec HS-82s
I didn't use the plastic motor mount collars (the white 20mm ones). I used 4 wheel collars instead. I didn't like the way the motor stuck so far out with the ones inlcuded with the plane.

Can't wait until later this month when I have an opportunity to really wring it out (weather permitting). I'll also have to confess to my un-intended flight.

Flyermark,
Congratulation and good news on your madden flight, intended or not. I'm also flying on grass and it makes the landing rather tough.
I haven't tried a third flight as I'm searching for a field with a runway.

I'm still having a tail heavy problem and by battery needs to be as far over the motor as possible(with additional 6 ounces). I really think I got one of the earlier kits that had the major problems.

Hi all,

I just finished assembling this ARF last Sunday. Like most of you I was frustrated with the errors and lack of logic in the instructions. Several parts were not in the bag while some useless ones added.

I could'nt resist to write to Horizon and share my view as those mistakes were reported a long time ago in several forums - how come it is not corrected now?

If I recall correctly the date code ink stamped in my fuselage under the cock pit was from March of 2008. Relatively recent I guess. I bought it in September.

Given the amount of weight and battery placement there has to be something very different about yours vs. mine.

I purchased and assembled the Pitts a few weeks ago. After reading all the posts, I was nervous to invest some money into a possible failure, but the plane looks to good on the box to pass up. I assembled the Pitts using the 15e power set up which ends up almost being too much power. The instructions are a little unusual telling you to assemble and attach the wings and tail feathers before installing the servos so I set the instructions aside and built the plane how it makes sense to me. For those who built by the instructions I believe they miss label which side of the cabane is top and which side is bottom. I found that the predrilled holes really only line up in one direction, but if you follow the instructions, you might end up with the wrong incidence on the upper wing leading to possible flight issues. Assembly time was maybe a little over 8 hours. First flight required a few clicks right aileron and two clicks down, and she was tracking straight. Take-off is incredibly realistic, and flight characteristics are incredible with almost no bad habits. Stall speed is good making the landing an uneventful experience. I have been flying for some years now and have never owned a plane that I liked flying as much as I like flying this. I have maybe 30 flights now with out any issues. Other than the order of assembly in the instructions, I cannot find any thing I would change with this one.

Hi all,

maidened it today. Here it is: quit whining about this bird, this is a great model!!! Other than previous comments on parts and manual, I had a blast with this airplane...very impressive at the park. Agile, powerful, solid. And I don't give a s.... about the 3D stuff.

Here's some technical tips:

-I added 28 Grams of lead (4 pieces) in the nose for more authority when landind and less tail-heavy feelings

-Reduced the motor spacers about 7mm to reduce the space between the propellor and the cowling

-With an Eflite 25 motor and a Rhino 3700 MHA 4S 20-30C pack, this thing is on fire !!!
For some who are interested, you can buy this pack from Hobbycity; the size and weight is perfect for this model. With this kind of torque I can take off within 10 feet!

-My Zippy 3S 4300 MHA pack was also very decent, plenty of power but not a powerhouse like the 4s...

Took advantage of some very warm, breezy weather here in Michigan. While the Pitts was blown about in the 10+ mph winds with some strong gusts it is just a blast to fly. I absolutely love this plane.

Wind walker - any luck on your issues? Regarding the grass field I found it best to try and get a nice stall/3 point landing. Yesterday's wind made that very easy. Taxing on our field can still lead to a nose tilt when I hit the "grass pot holes" I brought it in as close as possible to minimize the walk and disruption to other flyers.

Has anyone tried a glow engine in this one? I haven't looked into an engine yet but I was thinking about a small 4 stroke. Nothing against electric I just like the sound of a 4 stroke.

I have a GP Super Stearman bi plane. I was having the same problem with the incidence. This is what I learned...it's best to use the incidence meter (I use the Robart) while building any plane especially a bi plane.
This is the procedure that I'm going to use from now on. Attach the lower wing in position...level the plane so that the meter reads zero also make sure it's level laterally. Install the horizontal stab per the instruction, make sure it’s “0” and leveled laterally to the lower wing. Measure the wing tips to horizontal stab tips as usual.
Now that the front and back wing are set check the fit of the upper wing, the incidence is usually “0” but check it to make sure. If you can’t find the incidence in the manual call the plane manufactures tech support they should know it. After you got it set right screw upper wing down per the instructions. Now double check again that all the incidences are a correct.
As far as the CG, I would start with it a little forward. If for no other reason to make sure you have a good landing.
Hope this helps!
Shubova
[8D]
Don’t for get about my original question.

I glow motor of any type would rip it apart from vibration, Its too lightly built in my opinion.

That is why I asked if anyone had tried it. I thought the airframe was a little flimsy too. I was thinking of enforcing the nose area. Reguiling the all the joints and adding some reinforcing with 45 degree stock balsa to the rest of the fus. As far as I can see speed shouldn't be a factor, it will probably fly faster with an electric...I guess.
Just formulating ideas for future projects...
I just started on the E-Flite Taylorcraft for a customer it’s very similar in structure and size to the Pitts. It will be electric.
I'll be writing a review on it...should be fun.
Thanks,
Shubova
IFlyRC4Fun
[8D]

Oops![sm=spinnyeyes.gif]
...Regluing the all the joints...
[8D]