angel@edsel.UUCP (A Gomez) (07/01/85)
** MUNCH MUNCH MUNCH ** Has anybody in flying netland had any experience with "Hoerener Wing Tips". Im getting my piper painted and these tips caught my eye in "Trade A Plane". The manufacturer claims "3-5 MPH cruise increase" as well as a slower stall speed, better economy, mom and apple pie. My question is to those who used them or know of their use as to whether or not they work as advertised. They are not too expensive ($275 per pair for the PA28 series), and this is the right time to do it (before the plane gets painted). Thanx in advance for all the responses. Angel (ihnp4!edsel!angel)
cfiaime@ihnp4.UUCP (Jeff Williams) (07/02/85)
> Has anybody in flying netland had any experience with "Hoerener Wing Tips". > Im getting my piper painted and these tips caught my eye in "Trade A Plane". > The manufacturer claims "3-5 MPH cruise increase" as well as a slower stall > speed, better economy, mom and apple pie. > > My question is to those who used them or know of their use as to whether > or not they work as advertised. They are not too expensive ($275 per pair for > the PA28 series), and this is the right time to do it (before the plane gets > painted). > Such a wonderful subject, wing tip design. There are rounded tips, plates, tip tanks, and Horner's. We have tips that go up (winglets), and tips that go down (droopies). All of the tips promise life, the universe, and everything. Wing tip shape helps to define the wing tip vortex and induce drag. Any device that keeps the high pressure under the wing and the low pressure on top of the wing will help. Horners work, but probably not as well as advertised. They look good, however. The increase in aspect ratio for the wing may also help, depending on how the tip is constructed. As a pilot, you probably will not notice a difference between wing tip styles. The droopies on the C-152 may increase your cruise by 1 or 2 knots, but is not noticable. When delivering a flight of C-152s to Canada, I had the chance to compair a "droopie" with a "plain" wing tip airplane. Both airplanes in the flight used the same power setting, and the formation was loose enough so that the wingman (or number 2) did not have to jockey the throttle at all. Both airplanes used within 2 gallons of each other on a 1000 mile (or so) trip from Wichita to Winnipeg. If the "droopie" tip was so much better, that airplane would have burned much less fuel on the trip. Each airplane use about 60 gallons, so there was a difference of under 5%. The difference could have been from one airplane not being level during a refueling operation, longer ground running time (typical during these flights), or leaning techniques. (By the way, we were told to fly these airplanes at engine redline - 50 rpm, and lean on the left mag per normal leaning procedures. After this breakin, we NEVER had a customer yell about a bad engine. The ferry pilots who "babied" their engines had a large number of complaints.) Anyway, do the tip if it makes the airplane look good. Jeff Williams AT&T Bell Laboratories ihnp4!cfiaime