sjhanc

My Feedback: (3)

bucho, The TF retract mechanism will fit with a lot of cutting/grinding on the gear well and the retract's frame, but you will have to buy a set of Robart struts ($) for the H9 60 cc Mustang. If you don't mind the extra work to fit the gear into the wing you can save a little money there. The wheels you have will work fine. I was told that my DA 50r would not be powerful enough for this slightly larger plane but the results proved otherwise. The lighter airframe gross weight you end up with can have a better climb (at speed) and a higher top speed than the same plane with large engines bolted to the firewall that have drag-producing mufflers and cylinders protruding from the cowling. The H 9 wing's airfoil design is much better than the TF mustang's is (I have both planes), and because of the H9 Mustang wing's greater efficiency (better lift-over-drag airfoil), the model can be successfully flown with any motor or engine you can fit to it. Take into consideration the fact that that the TF ARF Mustang's engine cowling has a larger cross-section so bigger engines fit into IT easier.

The larger engines will climb off off the runway at a steeper angle (larger props) but their installation drag will hurt their top speed. The smaller engine's smaller props hurt initial climb at takeoff speed but better engine installation streamlining allows lighter gross weight and higher top speed and, lower takeoff and landing speeds. I think the DA 60 is the best compromise of the motor/engine possibilities but I also believe that high-output gas engines like the ZDZ 40 will fly this plane also, and won't be left behind in the gaggles.

Any motor/engine successfully used to fly the TF GS Mustang will perform better when installed in the H9 Mustang due to the difference in wing design. The bare H 9 Mustang airframe is lighter than the TF Mustang by several pounds. This gives the pilot of the H 9 plane a wider choice of power/equipment options, and the lighter, the better. If you take pains to install radio equipment so that it does not need ballast in the nose for CG, light gross weight is achievable and the payoff is better all-around performance. In pursuit of this, I have move the elevator servos up to the fuel tank area, replaced the heavy steel hinge rods with carbon fiber, installed a smaller, lighter, tail wheel, and left off the tail wheel doors. I had to go to my stock of old Sullivan carbon reinforced plastic push-rods (no longer in production, but the best push rods I have used) to find a lighter elevator control solution. And, (I can't emphasize this enough) engine cooling baffles are required, and the kit supplied baffle is not enough to do the job.

I have built and flown two H 9 60 cc Mustangs and both of them came out at 27 lbs 5 oz. ready-to-fly and no ballast was needed for CG. I bought the Robart pneumatic retracts for them but found that the retract's air cylinders (as supplied) were chosen for installation convenience but would not work in flight. I had to install longer air cylinders (from the TF retracts) and reverse the barrels to get in-flight reliability. The simple solution is to use the Eflite retracts and keep the airspeed VERY slow until they have cycled up OR down.