HOBBYKING C-47 REVIEW


C-47 NoseC-47 Battery accessC-47 Nacelle detailC-47 Opening passenger door


1/3/2015 - I bought the HobbyKing 1600mm C-47 for myself as a Christmas gift.  I paid $287 plus $17 shipping. The kit arrived with good packaging and no shipping damage. The contents looked good and were complete. Paint was even and 3 sets of different countries decals were provided to detail the plane as US, GB or Russian.

Assembly was straightforward. No glue is required. The elevator and tail bolt on and the wing slides together with a shaped plywood spar inserted for strength. After that you need only install the control linkages.

The most diffucult task is figuring out what to do with all the wiring in the wing. The plane has 1 elevator servo, 1 rudder servo, 2 aileron servos, 4 flap servos, 2 navigation lights, two landing lights, two retractable gear, two ESC’s and a separate BEC wiring to contend with. The kit comes with wiring harnesses to tie the servos, lights, gear and ESC’s together, but it is still a large clump of wires.

The decals are pretty good three part affairs. They are peel and stick, but after applied to the plane the outer plastic is peeled away leaving just the color decals with no clear backing.

I had serious issues with the kit when I managed to burn up 7 servos in the plane to the point of the cases melting. At first it seemd like I just had two bad servos. One aileron servo worked and then stopped and buzzed. One flap servo acted like it didn’t reliably know where center was and kept sticking at different positions randomly when moved. I filed a warranty claim with hobby king and waited. They never contacted me so I bought 4 spare servos and installed two after testing to make sure they worked. Because of the planes contruction and long servo leads you have to cut wires and solder in the wires of the new servos. Initially these servos seemed to work fine, then they started acting like the previous set. Thinking one of the Y connectors they had provided was bad I plugged two more new servos directly into the receiver. I powered them and kept an eye on them while I moved them. Before long they were almost too hot to hold. Around this same time the other aileron servo that had been good stopped working and started smoking. At this point I knew the cause of the issue. The kit supplied BEC was outputting nearly 8 volts. 

Not having a BEC capable of connecting to a 4S LiPo I replaced it with a 1500mAh NiMh battery. It was mounted near the CG on the plywood support inside the fuselage behind the battery tray. I replaced the damaged servos with spares I dug up and finshed the kit.

I used a 4000mAh 4S battery for power to the motors. CG was slightly nose heavy as measured at 90mm from the root lead edge. This was reported by HobbyKing reps on RCGroups to be the correct starting location. The manual called for 65mm. The problem was that the illustration and the measurement did not agree. So people asked HK what the right CG was. Another RCgroup contributer did the math and his math agreed pretty closely with HK’s recommendation of 90mm. The battery was all the way back to the rear of the battery tray to achive this CG.

The manual did not specify control throws. After reading posts in RCGRoups on the need to reduce Ail, Elev and Rud throw I dialed mine down to about 60% throw with 40% expo for low rates. This was with all the linkages at the outermost holes on the servo arms and control horns. My flight was done at low rates.

I took off without using flaps. After a scale like take off roll the plane lifted off at about half power and started a nice scale like climb. I left the throttle at half until about 200ft. When I increased the power to full at 200ft the nose pitched up and it took a lot of down elevator to reduce the climb. Even with most of the elevator it still wanted to pitch up and climb nose high. At first I thought it was behaving as if it was tail heavy, but after reducing the power to around half, elevator and climb rate were easily controllable and the attitude of the plane was level. No elevator trim was needed.

So long as I kept power at or near half it behaved as expected. Plenty of elevator authority, roll and yaw control without being sensitive. Increasing to full throttle caused a steep climb. When mild turns were attempted with full throttle and minimal elevator the plane snap rolled. This occurred several times. At half power settings it grooved around nicely.

A long landing approach at 1/4 throttle produced a nice slow descent with slight down elev to maintain a nose down attitude.

I dropped gear, then flaps and setup for a straight in landing. I hadn't mixed in any down elevator with the flaps so it ballooned a small amount until the speed bled off, then all it took was slight down elevator to keep a slow and steady rate of descent. It floated level in ground effect for the last few feet and then a slight pull on elevator was applied to flare for landing.

Touch down was smooth and rollout was uneventfull as it slowed and dropped the tail. I taxied in and decided to move the battery forward 3/4" to see if it effected the odd full power climbout issue and snap in high power slow turns. The result was the same. I replaced the pack and prepared for another flight.

As I taxied out for the second flight the right gear hit a small rut in our grass field and the plane nosed over. It broke two blades on the right prop and one on the left one. In addition both prop hubs were broken. They appear to made out of painted white styrene plastic. On further inspection I discovered that both motor shafts were also significantly bent. This from a slow speed taxing nose over on a relatively smooth grass field.

So I packed it up to head home. While unloading I picked up the empty fuselage by the battery compartment area and the entire nose snapped off at the back of the battery compartment. What I discovered is that the plywood battery tray was glued only in the battery compartment nose area. No glue had been applied to the plywood were it extends into the fuselage area to act as structural support for the battery in the nose. The entire nose with battery was only supported by the relatively thin foam of the forward fuselage.

I strongly advise anyone with the plane to inspect for glue where the plywood battery tray overlaps the area behind the battery compartment and extends into the fuselage.

You would also do well to check the motor incidence before the first flight. Judging by the fragile nature of the props, hubs and motor shafts it would be a good idea to keep spares. If you nose over in any way inspect the motor shafts and prop adapters for runout afterward.

© Charleston RC Society 2017