Flight report - Spring practice at the Zambelli Aerodrome - and taming a runaway fp.40

There are so many topics I want to respond to, but I just haven't had time. I hope to do some good reading and replying to all of your threads later this morning. Meanwhile, It's been a while since I got anything for a flight report. So this is from Sunday.

Windows of opportunity for flying have been precious few lately, with the Spring winds blowing every day. But with the season opener in my neck of the woods coming up in three weeks, it's time to practice some patterns and make sure the planes are in tune. Besides if I was afraid of the wind, I'd have no business entering contests. I've been flying the Cardinal pretty well this Winter, and can fly any of the stunts very well at one time or another. Stringing them together is another story. I suspect that's true of most stunt pilots in my Intermediate rank. I've been Int. for longer than I'd hoped, but I enjoy plugging away at it. I hope to someday Belong in Advanced. I might have seen a pilot or two in Adv, that look to me like they belong in Int. Lol... but I'm not a judge.

So Bob mowed a circle and we flew some planes. We flew in survival mode. The windsock at his neighborhood runway was rigid, standing straight out. Bob's buddy, and my recent acquaintance Jim Stoia, both aviators estimated 10-15 with 20 mph gusts. It was clean coming across the field, and slamming a row of trees on the other side. That made for a lot of excitement, a really close call, and one incident. I've never had a solid wind at my back and had the plane come in on me at the top of a loop like my Cardinal did once. Another time climbing into a wingover and having the Oriental swatted off course so bad I ran and caught it a few feet off the ground. We both had flights like that for most of the day. I aborted maneuvers I wouldn't have in a contest. Bob flies so fast and freestyle, I wouldn't know if he aborted anything or not. Jim watched. Being a recent CL retread, he was reluctant to risk his plane. Can't blame him after the show I'd put on, flying, running and dancing.

My Cardinal and its LA .46 are on song and ready to go. But my Oriental's fp.40 has been giving me fits since last Fall with runaway screaming lean runs that usually start while pulling up into the OH8s. I've added head shims, flown without the cowl to keep it cool, but can't tame it. It always ran great till one day it didn't. So a couple of weeks ago I gave Bob my spare .40 head to hemi out. This engine has always had really high compression, so much I can't usually hand start it. It's been finicky about priming and cranking from day one. The reworked head he handed me looked like a soup bowl compared to the original small combustion chamber. I realized what little a shim or three really does compared to opening it up like this. For the sake of comparison I put up a flight with the stock head and three shims. Sure enough it went lean right on schedule and worse than usual, so bad that it sagged any time I tried to climb overhead. And I flew and flew and flew flat laps.

After it cooled, we bolted the new head on with two shims(I think). I short-tanked it by an ounce because I'd turned way too many circles on that last flight. Off she went with a nice throaty 4 stroke, but good speed and felt like it had enough authority to climb into the wingover. As soon as I turned up, it broke into a clean two and powered overhead, breaking back into a 4-stroke on the downside. It turned on and off like Swiss clockwork on every stunt I flew for the whole flight. The only other engine I've had that sounded that pretty in a traditional old fashioned stunt run is my Max-S.35. And to add serendipity to the whole thing, it's more fuel efficient. I used to need all but a half ounce of the biggest tank I can cram in it to have any laps after the clover. Like I mentioned, I short-tanked it with only 4 ounces, and had plenty of laps left over. So for anyone with an unruly fp.40, I highly recommend opening up that combustion chamber. It did the trick for me. I wish I'd taken a picture of it.

So I'll call this day a success. Had a lot of fun, and mission accomplished, I have two strong planes ready for Huntersville, and hopefully a couple more days of practice between now and then... and try not destroy any of them between now and then.

I have some video crunching that I'll post later.





This is Bob's Icarus Jr. It has, of course, a very old badass engine. A rear induction dual BB engine. I forget the vintage and name. Hopefully he'll drop in and tell us(I posted this over at Stunthangar too). It may be from the late 1940s, but that's close to the beginning of glow ignition, so I'm not sure.