onewingtoolow

My Feedback: (2)

I just completed my Sportsman Aviation (Global) 60 size P40 ARF. Everything seems to be fine, except the instruction says the CG should be 130 mm (about 5 1/8 inches) behind the leading edge of the wing. This instruction specified CG is about 1 and 1/4 inches behind the spar. I am afraid if I add weights at the tail and make the CG on the instruction specified location, this airplane is going to be very tail heavy.

When I start with a new airplane, I always start with a CG that is a little bit nose heavy. Most of the time my initial CG is either on the spar or immediately behind the spar. So, I wonder is it possible that the CG specified by the instruction is wrong?

Notice that I balance the CG with landing gear up (retracted).

I appreciate your comments.

whstlngdeath

My Feedback: (15)

I suggest you test the manufacturer's location by putting the model on a good CG balancer at the location specified on the instructions and see where it hangs. It may be closer than you
think. If it shows a very nose-heavy condition, I would then
question their location. I'm not too familiar with this line of models
but you might try contacting Global distributors directly. I learned
on their Global RCM trainer, which arrived damaged in the box.
I called the customer support number in the manual and they
quickly remedied the situation by shipping a replacement part at
no cost within a few days. They do have good service. I'm not
sure if they put out changes to their manuals and instructions as
Great Planes does, but it's worth a call.

catboater

My Feedback: (51)

I've got their .60 Spit and the cg in the manual is where I'm flying it now and from the beginning. I'd go with the manual.
Throw the pushrods away and get some stiff ones. My elevator fluttered on the second flight coming out of a loop. It broke the stab but I got it back in one piece. Since then it's a great flyer and looks good too. I sprayed it with dull clear Lustrekote and it really brought out that warbird look.
Please let me know how the P-40. I'd like to have one and if it compares to the Spit,,,,well, you know the rest.


After rereading your original post I too, question the specs. Anything behind the spar worries me.
Hopefully someone else here already knows the answer and they'll fill us in.

onewingtoolow

My Feedback: (2)

whslngdeath and catboatr, thank you for your very useful input.

My airplane currently balances right on the spar, which is about 4 inches behind the leading edge. I am ok with this CG. But, if someone wants me to put weights on the tail and move the CG to where the spec says (5 and 1/4 behind leading edge), I suspect the airplane will be tail heavy and I would be very reluctant to do it.

I will continue to wait for more people to comment on this subject. I will also call Global about this. I will also share with you about what Global tells me.

Thanks.

onewingtoolow

My Feedback: (2)

I called Global today. The tech told me that the CG should be on the spar.

Thanks.

snyder_man

My Feedback: (52)

Does the P-40 have 90 degree rotating retracts? I've been wanting to buy one but I want one with rotating retracts. How about some more detail on your thoughts of the Warhawk and the Spit.
snyder_man

onewingtoolow

My Feedback: (2)

I just completed assembling this ARF the other day and have not flew it yet. The following are just some of my observations so far. Overall, I am quite happy with this airplane.

1. This is a "sport scale ARF". So, you don't expect it to be very scale.

2. I don't like its covering. So, I tore off the original covering and re-covered it with flat monokote. The original camouflage color scheme is not scale at all. It is very glossy, and the underneath of the airplane is a bright blue that you don't see on almost any WWII airplanes. After the re-covering, I like this airplane much better.

3. The construction seems to be pretty good. As expected from most ARFs, there are a lot of hot glues. The parts fit very well together. The airframe seems to be strong and straight. Since I tore the covering off and had the opportunity to see how was this airplane put together. I would say it is constructed as good as my other H9 ARFs.

4. I use a Saito 100 for power. I use two servos for both elevator halves. I did not use the hardware came with the ARF. Instead, I use Dubro and Sullivan hardware.

5. I did not like the retract came with the ARF. Instead, I used a Great Plane mechanical retract. I also enforced the structure close to the retract. The airplane is not set up for rotating retracts. But, if you really want rotating retract, or, if you want to use pneumatic retracts, you can always modify the structure and make it work. It all depends on how much time and money you want to put in this airplane.

6. I will not be able to fly in the next two weeks. Once I get a chance to test fly this airplane, I will share my experience with you guys.

onewingtoolow

My Feedback: (2)

Well, I had an opportunity to go home a little early yesterday afternoon. So, my P40's maiden flight was on. The hobby shop owner, a very experienced pilot in our club, test flew the newly completed Sportsman Aviation P40 ARF. This airplane is great.

Taking off was quick. Actually, a little bit too quick. So, the test pilot made some elevator trim adjustment right after the taking off. During the next few minutes, he put in some more elevator and aileron trim adjustment. After that, he was having a good time. He made fast and slow rolls, loops, snap roll, etc. It flies great. We had cross-wind at about 15 mph during the test fly. But it did not cause him too much trouble when he landed the P40.

I had a Saito 100 mounted inverted. I used a pump to help its performance. This engine pulls this 8.5 lb airplane very well. As the landing was so smooth, it was hard to tell if I strengthened the landing gear area enough.

I did not fly as the rain was coming and my starter had trouble. I look forward to the next opportunity for me to fly it myself (supervised).

JTWILLIE

I have purchased a used Sportsman Aviation P-40 and I would like to buy a new cowling. Does, anyone know how you might go about this. How do you contact Global?
Cheers
JT

bentwing_J

goto:

http://globalservices.globalhobby.com/

JTWILLIE

Thanks for the info. I do believe I have a new cowling on order.
Cheers JT Williams
[email protected]