How much does the Horner wing tips add to standard tips on model 7?
George
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How much does the Horner wing tips add to standard tips on model 7?
George
What specifically are you asking about ?. Ie cost, performance, handling ....
Asking how the use of Horner tips effect wing length.
I believe they add about 6-8" to each wing. If you need more accurate info, someone else may have exact measurements.
I have them on my SS7, but if I were doing it again I would go with the standard tips. They definitely add more wing area, which I think is unnecessary. My kitfox seems to float longer and has a somewhat flatter landing approach than friends I fly with who have standard tips on their SS7's. They are supposed be more efficient in handling the wingtip vortices, but I don't notice any measurable difference. Others may have different opinions. They also make it more difficult to install wingtip nav and landing lights.
George,
The length may vary from build to build depending on how a person cuts & fits the tip; however, ours add about 14" to each wing.
Dave's comment about the cuts is spot on. When I built my first Model IV, the plan was to fold the wings and keep it in my garage. With that plan, building to minimal folded length was critical. I cut them really short and modified the lower surface contour by grinding the glass a but thinner for easier bending to shape and then adding glass to return to the original thickness. A move rendered the need for short moot, but always liked the look vs. the droop tips otherwise available.
Tanks for info! Think I’ll go with standard tips especially since I will have wing folded issues with space as Lowell talked about.
I'm with Jim on this. I have Horner wingtips and I wish I'd stuck with the standard. I've added Nav lights and strobes, but I've had to cut and build support for landing/wig-wag lights. I've spent heaps of hours on this and not sure it was worth the trouble. So my suggestion is exactly what you're doing ... stick with standard.
I want to clarify my previous remarks. Although a challenge to a degree, I never regretted the effort going with the then standard Hoerner wing tips. In fact it may have been one of the choices that gave my first Model IV one of its characterics – it was very fuel efficient. In our annual flight of six excursions to Idaho in the early 2000’s I always bought less fuel than the rest of the fleet. On the first trip at our fuel stop after the first 3 hour leg, I loaded under 8 gallons of fuel. Next was about 10 gal. and the highest, a Rans S-6 at a bit over 13 gallons. It should be noted that the group included a Model IV with a 582 and group speeds were typically under 90 mph.
The following link will tell the story of the development of the Hoerner wing tip and possibly explain its introduction in the early 90s to replace the original droop tips as the standard factory wing tip.
http://buyplaneparts.com/the-hoerner...-design-story/
I do know the drooped tips can give you a good rap on the head that probably wont happen with the horner style. The flaperons can get you either way. It always happens when I'm wearing a baseball cap, and don't duck far enough. JImChuk
Thanks Lowell, that is a very good article that I believe I read years ago, and is the reason I opted for the Hoerner tips to begin with.
Thanks for posting that link Lowell... and it's also corrected my spelling !. I chose these wingtips because I knew they reduced drag due to W/T vortice reduction and I think I read somewhere else that they also give you an effective increase in Aspect Ratio (beyond the physical wing tip-to-tip span measurement). But Jim, I'm interested in your comment somewhere else on the forum that you tend to get a bit of float on landing with these tips. I'm about 4 weeks off finishing my build and I'm interested to understand why that would be happening before I start on my phase 1 testing. Is your approach speed a bit high or is it just a natural aerodynamic characteristic of this type of tip ?. i.e. greater ground effect due longer effective wing span ....
David, yes I am fairly sure I get more float on landing, but this is my opinion only; nothing scientific. It makes perfect sense to me, after all the Hoerner tips add roughly 3 square feet to the total wing area-that's a lot. The greater efficiency probably cancels out the increased drag from the area increase, but still maintains the increased lift. These tips probably really help in high DA operations, but are just not necessary for the kind of flying I do. Possibly a good compromise would be to install the Hoerner tips but cut back the inboard edges quite a bit to reduce the added wing area; just keep the fancy contouring near the outboard tips. This still leaves you with a lot of fiberglass work to install nav/strobe lights. Just my 2 cents worth.
Thanks Jim. I've thought of that very idea of cutting the tips back at the inboard edge but decided against it ... at this stage. As for the F/G work for the nav/strobe lights etc.... I think I've spent more hours fiddling with this and the landing/wig wag lights than I did with fitting up and aligning the cowls.Quote:
Originally Posted by jiott