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RV with Negative Flap Setting

ten4teg

Well Known Member
Has anybody out there experimented with a negative flap setting in cruise on a RV? A friend of mine purchased a CT Light Sport which has a -12 degree flap setting for cruise. He says it picks up about 15 knot when put in the negative setting. Anybody have feedback on this? Thanks Tom
 
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Run a search on "negative flap" and "reflex flap" Lots of posts and discussion.
 
Tom,
In addition to my 7 I have an Avid MKIV with a STOL wing which uses -6 reflex on the flaperon in cruise. If I remember it made about a 3 MPH difference. On my 7, my flaps would be about -3 degrees if allowed to go completely up. Before setting a joggle to limit them in the full up position I decided to do some tests during phase I using the -3 reflex and zero positions. The difference between the two positions is negligible. I really can't determine any speed difference in cruise or stall speeds. When moving from the zero position to the -3, I can feel a slight loss of lift and compensate with a slight pitch change, but that is about it. My cruise speed may in fact be too slow to see an impact with a reflexed flap. I am in the process of finishing up the wheel fairings and will retest when complete. I don't believe the 7/8 wing would benefit significantly from the use of reflexed flaps. If you search on "reflex" there are several threads mostly RV-10 related on the subject.
 
Has anybody out there experimented with a negative flap setting in cruise on a RV? A friend of mine purchased a CT Light Sport which has a -12 degree flap setting for cruise. He says it picks up about 15 knot when put in the negative setting. Anybody have feedback on this? Thanks Tom
I can't say that I've tried it in a RV, but we do use -6 deg flaps on the CT here in the US - other countries get -12 flaps, but the CT is too fast for the LSA rules with -6. It adds about 10, maybe 15 kt and the airplane really accelerates (and sinks a little) when you go from 0 to -6 degrees.

TODR
 
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