Very nice looking model. I read the review. I just had the first flight on my Alfa Models Corsair. So all this is fresh in my mind. Given that the Styro P-40 requires some assembly (which some people prefer), is $10 more expensive, has smaller ws (not by much though), had issues on first flight ( may or may not be repeatable in other kits), and motor is hard to access,... I think the Alfa Models has'm beat,.. but then Alfa dosen't make a P-40. And we all know we buy on emotion. But jeez, these are nice models. I guess we are lucky to have so many choices of manufacturers of fantastic looking models. I'm slowly turning into an ARF addict. Nice review very refreashing to get an honest review,.. not used to that I guess.

Edited

Fred G.

Martin has done a very nice job with the P-40 review, however I have to make a comment to his flight assesment.

Torque from the motor does not directly effect yaw stability, nor can it be corrected by right thrust. An aircaft "YAWS" to the left with a CW rotation prop (from the cockpit) due to P-effect. This is the differential thrust produced by the inclination of the prop disk to the true direction of flight. The downward prop blade is at a higher angle of attack than the rising blade creating more thrust on the right side of the aircraft. This "yaws" the model to the left.

The "roll" to the left is a result of the rotation of the prop. With speed (and typically lower Angle of attack) both "problems" go away and neither are easy to trim out in low speed, high power flight with fixed-type configurations. Right thrust does help the left -yaw problem, but will do nothing for the roll-torque problem.

Some aircraft had offset vertical fins (hurricane) (or cambered ones, BF-109) rather than engine thrust offest. This was found to be easier to implement in the production line, and caused less grief when engine upgrade changes were made.

Trimming a model with a fixed rudder can work too, but becomes speed sensitive. A lot of deflection is required at slow speeds (where the problem is worse) and as the aircraft speed increases (and the AOA reduces) the amount of rudder trim required goes to near zero. If the model is carrying a lot of rudder trim in high speed flight, there surely will be a penalty in trim drag and the model will turn slightly better in one direction than the other.

To avoid snap-rolling any of the flying styro scale models with these large diameter multi-bladed props is to always launch the model with a brisk, level toss. With good speed, and a low inclination of the prop disk, yaw and roll out-of trim effects can be minimized.

Regards
Tom
(still flying is FS spitty)

Thanks for the indepth analysis, Tom.

Coming from a pattern and newly 3D background, I do know that left/right thrust can drastically decrease the change required in the set rudder trim from low to high speed. Right thrust in an airframe will decrease the left pull due to P-factor as it's simultaneously pulling to the right. The amount of right thrust required is the question mark. At speed it's not a matter of P-factor as the nose is not raised. Even in a high speed cruise on the initial test flight, she wanted to drastically pull to the left - symptom of too much left/not enough right thrust.

The simplest solution providing the least worries in the end is what I put in the review - a few degrees of right thrust and adding rudder control.

Your launch technique is exactly what I got into after the test flight. I don't go above 2/3 throttle in flight. Nor do I go below 1/3 throttle, including on approach. The yaw and roll effects are too severe otherwise.

Martin

Here's mine...

I found this review to be very informative. I have just had a similar experience with another small flying styro plane, the Teady bear. Mine was overpowered with a razor motor, and 9 inch prop. First flight was almost as described in the flying tiger review. Lots of torq, yaw instability at lower speed, tip stall. Well, it all happened so fast I didnt know what really went wrong. This review has shed light on my situation. Thanks!

Agreed! I have already emailed Mr. Hunter about my experience with the FS Spitfire which was the same, if not worse, than his P-40. Although the Spit's 4-blade prop REALLY made throttle management slippery as a fish.

Only I anticipated this and added a rudder servo to the Spitfire during construction. I also offset the prop 3 degrees to the right and 3 degrees down. But it was still a slippery fish. Nonetheless, I highly recommend adding rudder to these models. It only adds about 10 or 12 grams, including a 6-gram servo.

My intentions for teady bear are for extreme aerobatics, so am leaving it with zero offset. After its rebuilt, will change to a lower gear ratio, smaller prop, and second flight will be from rog to get a bit of airspeed over the vertical fin before jumping into the air. After mastering the teady beast, I may try the p40. Its one of my all time favorite fighters.