Into the Shop

This article appeared in the June 2009 Falco Builders Letter.

by Bob McCallum

N660RH has been successfully delivered to my home in Toronto. The Falco unfortunately didn't much like being submerged in water. A large number of the glue joints have failed and the structure, especially the lower surfaces, are pretty sad. The whole of the fuselage bottom and most of the lower wing surfaces are totally devoid of paint and the fiberglass covering. The adhesion has failed and whole sheets of the finish have come away leaving the bare wood exposed. Glue joints on the ribs, the longerons and those securing the skins to the lower surfaces have all failed leaving the structure very un-structural.

Instrument panel illustrating rusting of switches and fasteners

The gear doors were torn away, for the most part, with only the port main door semi-intact. The starboard main door is only a remnant of the original with just an outer ring remaining. The wheel cover on this main wheel is also severely torn up. The smaller doors over the gear legs are gone, as are the nose gear doors. All of the fairings on the bottom are gone as is the pitot tube.

The good news: Mechanically everything has survived. The prop is intact, undamaged. The engine must have been stopped and the blades horizontal on touchdown. The engine is completely intact and in good condition. It does not appear to have suffered from its 'dunking' and I have just finished dismantling it for inspection. There is no rust or physical damage to any of the engine components that I have been able to find so far. The only slightly dicey things were that many fasteners were very loose, and one of the pushrod tube retainer clips inside the rocker box of #2 cylinder had fractured leaving the exhaust pushrod tube unrestrained.

Bob used the small battery to cycle the gear and flaps, and both worked perfectly.

The alternator rear bearing was totally worn out to the extent that the rotor was rubbing the stator and so may not have survived the Atlantic crossing. The electrical components have not yet been evaluated but preliminary disassembly of things like the ELT, altitude encoder, etc, reveal extensive rust on several circuit board components and therefore most likely the electronics are history. The gear extends and retracts normally, as do the flaps, but in moving the control surfaces, I discovered that the structure was so weak that the pitch servo came away from its mounting in the floor of the fuselage. The bottom of the plane in this area below the baggage compartment is not much more than just loose bits of wood.

The flight instruments are partially filled with water and so are most likely junk, but I haven't gotten to them yet.

The official cause of the accident, by the way, after examination of the aircraft by certified investigators, was "carburetor icing." No one could find any other reason for the symptoms described by Simon and no mechanical problems were discovered. The carb heat control was found in the "off" or "cold" position; there was still plenty of fuel in the tanks. In fact, the front tank still has fuel in it today. [but keep reading ... more to come below.]

At last we come to the cause of the accident...

These are photos of the carb heat actuator lever which was broken off and detached from the carb heat box as the aircraft was found. There is some seriously deficient welding which was intended to attach this arm to the shaft which moves the door selecting carb heat. You can see that the arm was attached by only two very small areas on each side of the hole and if you look closely only one side of the break rusted, meaning that only one side was a fresh break. The other side had failed sometime earlier and had become oily preventing rusting. This combined with the fact that the carb heat control was found in the "off" or cold position leads further credence to the findings of carb ice causing the whole scenario, however caused by a mechanical failure and not pilot error.