planelazy

Well guy's the Yak got it's maiden today and i wish i could say it flew great but the c.g. was off and it was a hairy tail heavy flight.I had it balanced dry between the forward and rear ward c.g. called for in the instructions.It was one of those flights that i thought would never get down in one piece. The O.S. 160 was more than enough power .The good thing was it never showed any signs off snapping or tip stalling it just needs a more forward c.g. location but i did grt it back with no damage. Tim.

Skip

My Feedback: (76)

Well guess what? I flew my Yak on its maiden flight today and had a similar experience. The plane weighs almost 14lbs with an OS 1.60 up front and a Pitts muffler. It was tail heavy right out of the box. Nothing I could do to remedy that except to pile on the nose lead! I flew it slightly aft of the rear limit and it was a handfull. I got it back on the ground but the landing broke the 18x6w prop. I will give it another try but the plane has "DOG" written all over it. Thankfully the OS 1.60 was plenty of power and I used a Perry VP-30 pump.[:@]

planelazy

Skip. I am going to try and add a little more weight as mine came out about 12 1/2 lbs and did not exhibit any other bad habit's. I alway's felt it was over weight after being in the hobby for thirty year's and flying many planes of this type. I hatr to abandon it because it is a nice looking plane. Tim

tIANci

Man ... the two of you have the same engine and the difference is about 1.5 lbs! I always maiden my plane slightly nose heavy. For me I do not trust the GC stated. If its like e.g. 100-120 I will always set it on 105 with about 5 degrees nose down. So far have yet to crash on maiden flights, its a safe bet.

Skip

My Feedback: (76)

Frankly I decided not to add any more lead to the plane. I have discovered with some ARF's that they will fly very well at a c/g aft of the recommended limit. This plane would be OK even at that weight (13.5lbs.)but it defeats the purpose of my buying it to practise 3D flying without spending 2 months buiding a plane. If I crash it, so what? It's just money and not time. I am currently looking at several other ARF's to replace it such as the Chip Hyde Cap X or the GP Gene Soucy 300. Also, here in Georgia they sell an extreme Yak 54 which looks very good.

tIANci

Skip ... the Extreme Yak looks great, saw the videos on it, some people can really fly! I think the EF Yak is a lot lighter than the CMPro but again the CMPro is a lot cheaper. I was informed by CMPro that they have a new 50 sized Yak. I am waiting for them to give me the specs.

Skip

My Feedback: (76)

The Extreme Yak should be back in stock in 7-10 days according to the dealer in Georgia. I agree the video is awesome!

Buzz Lightyear

Guys

I test flew the GSP Yak for a mate this weekend. It has a Moki 210 in it and it still tail heavy. I think it is around 6.5kg. In the air it isn't too bad. I have rolled it, snapped it, tumbled it, hovered it, but trying to land it is .........scary!!!

The owner had a bit of a fly and then tried to land it. 6 attempts later he gave it back for me to do.

It is such a shame the model is a 'DOG'. It is a beautiful looking model that needs to go on a diet.

It is not fun to fly. It is hard work.

IMO, I wouldn't have one if it was given to me

Buzz

Skip

My Feedback: (76)

Thank you for the validation of my honest opinion of this plane. I landed mine for the last time. It drops like a rock!! I am going to get a Chip Hyde Cap X. Skip

tIANci

Okay ... I am cancelling my order! Forums are great ... the Extreme Flight Yak is soooooooooo tempting.

forestroke

Wait a second, Buzz you said that the plane doesn't want to come down and Skip you are claiming it drops like a rock... there is just something amiss about all of this. I have just bought one without a return policy and I am just wondering if I should continue to build it. I am about to invest about a grand in engines and high=torque servoes for this plane and if you're telling me you guys wouldn't touch it with a ten foot pole, I'd like to know why!

Buzz... with a little more weight up front, you think that it will be more manageable? Skip, I am not planning to 3d with this plane... you think it is good as a general acrobatic plane? Your comments would be great! Thanks...

Skip

My Feedback: (76)

OK, Let's settle this matter. I bought this plane for the convenience of not having to build during the flying season and to have a third plane in case I wipe out my others. I thought it looked like a good plane from the pictures. My mistake ($279.00) was to buy it too early and not wait for feedback from others that preceeded me like I normally do. Despite my reservations about the quality of GSP models I bought it . When the box was opened at first glance I liked what I saw. When I picked up the fiberglass fuse I noticed it was HEAVY. I made some c/g checks during assembly and knew it was going to be somewhat tail heavy. Nothing had been done to lengthen the nose moment or reduce the weight in the rear fuse. I put everything I could forward yet it still balanced about an inch aft of the recommended c/g point. I bolted on quite a lot of lead hoping down the line to remove some of it after test flights. In the air the plane was fast and and very pitch sensitive even with reduced throws and 40% expo. Something flew off the plane right away so I decided to land the plane to inspect it without really having time to explore the envelope. It turned out to be the monokote trim on the right wing. I set up for a fast landing (our field is 1000 feet long) when the power was reduced the pland sank like a safe and I recoverd but hit fairly hard and broke the prop. I don't see any point in experimenting with this plane any longer because my purpose in buying it was to learn 3D. In my opinion it is 2 pounds too heavy at minimum. But I have good news!! It looks nice and will make a pleasing ceiling fixture until I use it for target practice with my new .45 automatic pistol. Skip

Buzz Lightyear

Skip

I think we are being too negative about this plane. I am sure there is some good points about it.......I just can't think of any right now.

Forestroke

I gave the owner of the one I test flew some advise on how to make it lighter. He didn't do as I said. After he had trouble flying it, he has decided that he might make the modifications I recommended.

As you build the Yak, make it lighter!!!

IMO, Cut out the canopy base. Only leave the frame to glue the canopy to. Hollow out the root ribs on both the wings, stab and the wing and stab fillets. Leave enough material around the tubes and locating pins for
strength.
Take off the covering (carefully and you can re use it) on the rudder and stab and hollow out the counter balances.

I believe the Yak I test flew would have been 1kg lighter if it had these mods done and if it had a OS160FX instead of a Moki 210.

Guys,
The Yak in the air is OK. It flies......just......I think we are spoiled with the ARF's on the market these days and won't accept a crappy model.

As Skip is doing, the owner is getting another plane.

Cheers

Buzz

P.S If you are not an advanced or expert pilot, get one who is to test fly it.

forestroke

Thanks for the feedback Skip, Buzz...

I will build it... and try doing so lighter. I'll try to use a 160FX as far forward and move as many things forward of the CG as possible. I am a decent pilot but by no means an expert. I do take up a lot of planes for their first flights to trim them out for friends so that's not a problem... only thing is I've never flown such a large model. The largest so far is a merely a 40-46-size plane.

I heard that the larger they get, the easier to fly... I hope that's true...

Easy does it

My Feedback: (2)

Skip I am sure you know the 25% rule but let me just run it by you any way (not every manufacturer tests their cg math ).
From the centre of the fuse measure to wing tip take 25% of that and mark it from the centre of the fuse, on that mark measure from the le to the te and and take 25% of that and mark that back from the le, where these two marks intersect is your cg check it out before you shoot the plane (I'll send you range money if you send me your plane!!!!)

Skip

My Feedback: (76)

I am going to give this plane to a friend to install a G-26 up front. Hopefully this will solve the c/g problem. I am sure when the center of gravity is correct it will fly OK. My problem with the plane is that it is just too heavy to use for 3D practice. Once in the air it flew OK but it was not what I would have hoped it to be. "You pays your money and you takes your chances". Some times you come out OK other times you fall on your face. I'll deal with it.