PFM Logo Fokker Triplane Model T Curtiss Canuck

November 3, 2007 Project Update

Ready for taxi testing

We had an excellent turn-out, with Tom Gaylord, Charles Allen, Terry Bledsoe, Ted Dawson, Dick Schenck, Greg Solberg, Don Gaylord, Derek Staha, Al Sumrall, Sanford Swope, Dave Miller, Roger Ritter and Ron Marcotte all making an appearance for at least part of the day.

While part of the crew got to work on the hangar windows, the rest of us worked on the triplane itself. Don Gaylord is a master automotive mechanic and took over efforts to get the Le Rhone engine running on all nine cylinders. The problem seemed to be in the valve adjustments, so Don read the manual and set about adjusting the valve lash. Sure enough, only one cylinder was actually in spec and the cylinder furthest from spec was #1 cylinder, which was the one that wasn't firing at all. After the engine was run again, firing of all cylinders was confirmed with a laser temperature gun. Awfully high tech for a 1918 motor.


Weighing the airplane

A friend of Roger's showed up with his aircraft scales and a weight and balance was done. The aircraft weighed just under 1100 lbs, and the center of gravity was a couple of inches behind the leading edge of the lower wing.

Once the engine was running, the next step was to taxi the triplane around the field. In general the triplane looks great in motion! We even have some video of the taxi test (1 MB download).

Roger was concerned about the airplane tracking straight, but that didn't seem to be much of an issue. The engine was difficult to get to full power, and the lever kept creeping back on him. We did get a real full power run out of the engine after the groudloop. We will need to change out the cockpit controls to the twin lever arrangement that Roger is more familiar with.

Roger broke both wingtip skids in his taxi tests. He gently groundlooped while making a "U" turn at the end of the runway and broke the starboard skid's forward mount. He also broke the port wingtip skid in a faster groundloop. The airplane is very top heavy and tipsy.

We will likely "re-engineer" the wingtip skid's forward mount to something sturdier, since that is what failed on both wingtip skids. The other problem noted after the taxi tests is that the tailskid cracked through one of the bolt holes that mount the tailskid shoe. We will also try pinning the tailskid, so it doesn't swing from side to side. Roger thinks that will reduce the tendency to groundloop. There may also be some minor repairs to the port wingtip, lower wing.

That was about all the excitement for the day we could stand. The triplane was wiped down and put back into the hanger.