Dave Anders’ RV-4
I read “Putting the Experiment in Experimental” [March 2017] with a lot of interest. Clearly Dave Anders’ RV-4 is much faster than my RV-7. I want some of that! The article documents speed gains over years and how it was mainly aerodynamic cleanup rather than horsepower. Little was actually written about the 30 modifications mentioned in the header aside from engine tweaking. So, how can I benefit from this?
Pictures and captions listed aileron hinge canoe fairings, fuel drain afterbody fairings, inboard elevator fairings, engine plenum, convergence zone exit, and oil cooler afterbody. Not listed but pictured were Sam James cowling, tailwheel fairing, fastback fuselage and tight-clearance spinner openings. Maybe a great follow-up story would be a short series featuring aerodynamic cleanup of an RV.
What would be the best way to test improvements: full throttle and 2500 rpm or 2700 rpm? Should altitude be 7500 feet or 11,500 feet? Since most of us are after cruise speed, will a cruise rpm show speed improvements more or less than a low-level, full-effort pass?
What next? I have big cutouts in my spinner for prop blades. Wheel fairings have pretty big holes for the tires. Will Dan Horton’s tire rubbers make it faster? Hinge canoe fittings? Elevator trailing edge fairing? Maybe some more work on that cooling exit? What else could be done to improve cruise speed?
—David Lloyd
We’re glad you enjoyed Dave’s piece. We’re also looking forward to more details in future articles already planned for upcoming issues of KITPLANES—Ed.
Airport Personalities
There’s two airport personalities Tom Wilson left out [“Rear Cockpit,” March 2017]. First, there’s the guy who constantly shouts out, “He’s going to get someone killed flying like that!” Nothing gets an FBO’s attention like the thought of liability after a fatality at his operation. This guy has a clapped-out Tri-Pacer with a scratchy “avionics suite” and actively sets up situations where there will be a conflict in the pattern.
Then there’s the new CFI, fresh out of Embry-Riddle, teaching the latest techniques; I’ve been flying for 30 years, and I’ve never seen anything so dangerous. He’s going to get someone killed flying like that!
—Butch Gordo
Actually, Tom left himself out of the personality line-up as well…and he’s got quite the personality!—Ed.
Panel Cutouts
In “Plane and Simple,” [February and March 2017] Jon Croke shows techniques for making holes in panels. In today’s world, it would seem like less trouble and probably not that much more expensive to lay out the panel in software and have someone cut it with a waterjet. Of course, I realize many homebuilders prefer to do everything themselves and/or don’t have the computer skills to run the software. However, the waterjet option is worth mentioning, if nothing else.
—George Lazik
Yes, many people have panels laser or waterjet punched these days, but we like to show a variety of techniques and let readers choose what’s best for them.—Ed.
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