Mike Sylvester wrote: > Hey Guys, Are the naca vents that most people are flying with enough to > cool on a hot summer day ? I think that I saw a picture of a KR with > leading edge vents in the wings that were turned upwards after entering > the cockpit.(Like a Cessna.) Would this be O.K. or would it disturb to > much airflow ? Just a thought. It won't be long before I start on the > wings.
Jim Hill had what I think is almost exactly what you describe. He used some fairly small slots on the leading edges of the wings and piped the air from them into the cockpit. They worked great except they were so far inboard (in the stub wings) that they also picked up exhaust gases. So he abandoned those and installed real Cessna vents between the pilots and passengers legs (shown in the very bottom photo of http://home.hiwaay.net/~langford/jhill.html ) [not the legs, the vents!], and the result was "very satisfying on hot days". The wing slot thing is a good idea, and before I flew my plane I'd have thought that putting them on the outer wings would be a hassle during wing removal, but since I've only pulled the wings once (to return home from a broken crank), that's a non-issue. To answer your other question, the NACA vents work fine for me, but the one on the right works best of all because of propwash. The one on the left works OK too, but try your best to keep them as far forward in the bay because if the vent empties right in front of a vertical, the vertical will deflect the airstream towards the panel and you wont get any! I strategically placed piece of duct tape used as a ramp can rememdy this problem, but of course I calculated that, since I'd never make such a stupid mistake. Jim Vaughn located his just like mine, and after finding no joy on hot days, made a neat little scoop that poked out into the airstream about a half inch, and he said it made a huge difference. He used button type snaps to pop in on during the summer, and removed it for the winter. Those who built per the plans and have the widest part of the fuselage up near the panel will tell you that NACA vents suck, rather than blow. They would be correct for their airplanes, but if you've built the plane so that the fuselage is widest near the trailing edge of the wing, NACA vents up under the panel work fine... Mark Langford N56ML "at" hiwaay.net website at http://www.N56ML.com --------------------------------------------------------
