Warbird Rebuild—Skyshark ARF P-40N Repairs on the Cheap!
By: Michael C. Gross
Photos by: Marshal Gross & Michael C. Gross
It is quite exhilarating to make a low high-speed pass with a warbird at Warbirds Over Delaware, until you pull out in a hard bank and realize your propeller is no longer turning. That’s what happened to me this past summer at WOD, 2010 with my DA-50 powered Skyshark P-40. Before I could process what was going on, the model snapped and disappeared into the trees. As I stood there in shock, I realized that I never refueled after my last flight!
My brother Marshal and I along with WOD staff searched for the Russian warbird over 30 minutes in the thick briar patch. As we crawled forward, getting many war-wounds from thorns, we found the plane intact. This was amazing, for it went straight in from more than a hundred feet. The P-40 was suspended about two feet in the air, and never hit the ground. The briar vines were wrapped around the plane, as if it had been there for years. The WOD staff actually drove us into the brush in the shovel of a frontloader. We wrestled it free and were driven to a clearing. I have to thank Marshal Gross and the very helpful and equipped WOD staff for the recovery.
We put the gear down and began the “walk of shame” back to the pits. I was showered with many questions and comments from spectators on the way, including “Nice save!”, as if I had anything to do with the briars being there, and “What happened?”, which I quickly responded with, “It ran out of gas”, as if to exonerate myself of the incident. Unfortunately, I am not only the pilot, but mechanic and ground crew as well. In short, My Fault! I loaded the P-40 into my trailer, checked the fuel levels in my other planes and enjoyed the rest of the weekend.
Back home in the shop I started to assess the damage. The fuselage was in good shape other than some cosmetic damage. The wing had significant damage to the leading edges, aileron and flap horns pulled out, and the wing dowels broke free. First I peeled off the graphics and the covering back beyond the damage. The starboard wing was much worse, and much of the sheeting and forward ribs came off with the covering. I was careful to save all the pieces. The glue used at the factory seemed to be rubbery and I was able to pull the pieces of ribs free from the sheeting. Like a puzzle, I was able to save all but two ribs and reassembled them to the spar with medium ZAP.
I used some scrap 1/8th inch balsa to recreate the inner leading edge. Then I replaced the bottom and top sheeting with medium ZAP. To finish off the leading edge, I used a scrap of ¼ inch balsa. After it was all sanded to shape, I applied Solartex covering to the repair.
The port wing leading edge was pushed in at the tip, and I was able to pull it out and glue it with thin ZAP. A little filler and it was ready for a small patch of solartex covering.nbsp; I primed the repairs with automotive primer. I then used Tamiya spray cans from my paint stash, which were close to the factory light and dark browns and light grey, and dusted in the colors. Only masking the light grey on the bottom. I applied the new stars provided by Red5designs, and made new machine guns for the starboard wing out of fiber-glass tubes.
Next I had to repair the horns on the aileron and flap on one side. I sunk small dowels into the screw holes and drilled new holes for the horns. Then the wing dowels had to be epoxied back in. Luckily these pulled out clean and went back in place. I used 30 minute epoxy and a piece of wax paper between the leading edge and fuse to accomplish this.
The chin of the cowl had some stress cracks in the glass, which I soaked thin ZAP. I covered the thorn holes in the rudder with small vinyl circles resembling bullet-hole repairs. The canopy had a few cracks in it, and even a piece of briar inside. I used packing tape for the cracks, and left the briar inside as a reminder to always check the fuel!
The whole repair took a few days and the only cost was a new Mejzik 21X12 propellor, which I purchased from Nick Ziroli Plans. When repairing your ARF, be sure to save all the pieces, assess the damage, and look around your shop for free supplies to complete the repair. An important lesson can be learned here. We all have preflight routines where we check batteries, air, and fuel, but when at exciting events like Warbirds Over Delaware, we can easily be distracted and forget the simplest things like gas! Remember your pre-flight checks and have fun at all those events this summer.
Before you scrape a plane, especially a giant scale warbird, be sure to gather all the parts and pieces and try assembling the jigsaw puzzle. The Warbird you save may be your own! Certainly it’s a lot cheaper than buying and building a new one!
Engine – Desert Aircraft
Radio – JR 9303 2.4, hitech servos
Gear – Robart retracts and wheels
Propeller – Mejzik 21×12 2-blade carbon fiber
Model: Skyshark P-40N ARF
Distributor: Skyshark RC
Wingspan: 82 in.
Length: 71 in.
Weight: 23 lb.
Nick Ziroli Plans; (631)-467-4765; ziroliplans.com
ZAP; (800)-538-3091; zapglue.com
Robart mfg.; (630)-584-7616; robart.com
Red5designs; (631)-281-7633; red5designs.com
JR; dist. By Horizon Hobbies (800)-338-4639; horizonhobby.com
Hitech; dist. By Tower Hobbies (800)-637-6050; towerhobbies.com
Mejzlik; dist. By Nick Ziroli Plans
Solortex; dist. By Balsa USAP>
Desert Aircraft: desertaircraft.com
Tamiya spray paints; dist. By Tower Hobbies (800-637-6050)
Skyshark RC; skysharkrc.com