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Old Jul 29, 2012, 07:11 AM
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Larry Jolly's Avatar
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Graham, Thank you for your contributions on the HP-8. Your photos certainly clarify many points on the HP-8 including the work Moffat did to improve the wingroot separation issues. Really good stuff and much appreciated.
Larry
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Old Jul 29, 2012, 09:44 AM
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Issue of Soaring Magazine that includes an article titled: Flight Testing the HP-8.

http://www.ssa.org/magazine/Archive/...75/1959-10.pdf

Seems very technical, with equations galore but includes the picture of the HP-8 tuft test and possibly a description of what might have been done to improve things. I only glanced at it. I found it by Googling "August Raspet, HP-8."

Raspet was the leading researcher in low speed aerodynamics and wrote some wonderful stuff on the subject. He did not write this article, but is almost certainly referred to by the author.

I posted this as soon as I found it, so I haven't gotten around to reading it yet.

Edit: The most important thin mentioned is that the stall speed was reduced, first to 50 mph from 55 by the addition of fillets on the wing. It was further reduce to 47.5 mph by refining the fillet design. You can infer from that, that the plane flew with significantly less drag at 55 with the final fillet design. The work was incomplete since Screder had to leave. I don't know if it was ever continued.

Pete
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Old Jul 31, 2012, 05:13 PM
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I did a line drawing over the three view so I could carve a small RC model. A VERY SMALL model.

I've got servos and an RX small enough to fit and will probably try for pitcheron control. Worst case it'll be a solid model i can stick on a bookshelf.

The size is dictated by the size of balsa that I have to carve the fuse out of. 1/2 inch thick so the max fuse width becomes one inch, which makes for a very small model but I like to carve so why not?

I'm posting my drawing. Not very elegant, but neither is the three view. I include a second wing with slightly more chord.

It should be fairly scalable. if someone wants a simple model. Sorry for any crudeness. I was struggling with an unfamiliar app that had strange bezier curves requiring more than the usual amount of tinkering.

Pete
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Old Jul 31, 2012, 05:28 PM
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Quote:
Originally Posted by yyz View Post
Whoooopppsssss... Evelyn Wood Speed Reading course lets me down yet again. Sorry about that.

If you like the '70s-era stuff, this is a pretty interesting DVD:

http://www.cumulus-soaring.com/video...Case-Front.jpg

It's filmed in this bizarro Spaghetti Western style in black and white. A couple of interviews w/ the ninjas of the day (Holighaus, Reichmann, Moffat, et al). Not something to watch w/ the wife but some great shots of the first generation glass ships in action and an interesting point in history that shows how far the sport has come.]
My wife and I just watched Zulu Romeo: Good Start last night. We love it!
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Old Jul 31, 2012, 06:56 PM
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My wife and I just watched Zulu Romeo: Good Start last night. We love it!
Thanks for the tip. I ordered a copy.

Pete
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Old Jul 31, 2012, 07:22 PM
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that doesn't mean your wife will like it but i think its a cool movie, really enjoy the pilot interviews and the commentary. its no sunship games but it really isn't even meant to be the same type of film so its not really valid to compare the two.
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Old Jul 31, 2012, 08:32 PM
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that doesn't mean your wife will like it but i think its a cool movie, really enjoy the pilot interviews and the commentary. its no sunship games but it really isn't even meant to be the same type of film so its not really valid to compare the two.
No wife to worry about. This video is from the days when I was a fairly active sailplane pilot. I spent my weekends at the field, flying, running wing tips, chasing tow ropes, retrieving sailplanes and/or talking about gliders all day. I helped put sailplanes together, including the HP-8 and this film is basically about my youth.

I just saw the Sunship Games. I wish I had the sense to carry a camera back then. I have only two pictures from those days.

BTW, that's also when I learned to fly RC.

For reference, I'm seventy-four now, Moffat is about eighty-four and one of our tow pilots from those days is eighty-five, still passes his second class physical and still tows regularly at Wurtsboro in their L-19's which date from the late sixties, assembled from Korean war surplus parts by Al Parker. I think his Sisu is in the Smithsonian.

Yeah, I'm still hooked on this stuff, have my new plastic licence in my wallet but am a bit reluctant to get checked out since I can no longer spend half my life at the airport and the checkout costs about as much as several years of club flying did back then.

Pete, seriously looking forward to this film.
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Old Jul 31, 2012, 09:33 PM
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Agreed on the prices these days. I'm thinking about getting my CFIG back, at least then the flying is free, and instructing is fun. Only problem is that Bermuda High is 188 miles from here!

Al's Sisu is hanging in the Hazy center out at Dulles, along with Bob Stanley's Nomad and several other sailplanes.
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Old Jul 31, 2012, 09:35 PM
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you guys need to move to kansas, our tows are $20 to 2000.
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Old Jul 31, 2012, 10:49 PM
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you guys need to move to kansas, our tows are $20 to 2000.
Wow. I used to pay $1 for my first tow of the day (3,000 feet) and $2 for the first thou and $1 for each additional thou on subsequent tows. Club dues were $75 a year and the gliders (1-26, 1-23 and 2 Ka-7's) were free. One hour max if someone was waiting, unlimited if not. (on weekends there was ALWAYS somebody waiting)

I forgot what I paid for instruction, but power was $14 an hour for the Champ. $5 for the instructor and $9 an hour for the Champ.

Edit: I forgot to mention that commercial tows cost $5 to 3,000 feet. Our club, Sailflights would exchange tows with the FBO, towing his gliders or his crew towing ours each at the other's rate. The FBO (who's son taught me to fly gliders) had a 2-22 and a 1-26 when I started but eventually had a 2-32 and a couple or more 2-33's. After I stopped flying he got one each of the two last single seaters that Schweizer made. I never got around to flying them though. I was just an occasional visitor then.

Today it's $75 an hour for the ASK-21 but $500 for the check ride package. I have no idea what the tow costs. The field is no longer in the same hands and I think that one or maybe two 2-33's are still around, a couple of ASK-21's and a few private sailplanes. Also a couple of rather expensive motor gliders.

End edit.

Things are quiet compared to the field's heyday when there were two lines of sailplanes and four or five tugs going.

Pete
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Old Aug 01, 2012, 07:38 AM
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Wow, you guys are bringing back a bunch of good memories. I don't remember our rates, but they were close to yours. A 2000 foot "intro ride" was $7. My cost was one day of pulling tow lines and running wings for one dual instruction flight. That was 1966 and I was 13 years old. (I needed a lot of ballast to fly a 2-33 back then.) You can read a little about the operation at;

http://www.skylinesoaring.org/HISTORY/history-2.html

The HP-8 had been replaced at that point with HP-11s and -14s, which were the hot tip unless you went for the new glass ships. Dick's personal HP-14 eventually found a home at our operation after we moved to Warrenton. Someplace I have 8mm movies of it.
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Old Aug 18, 2012, 10:23 PM
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These pages of HP-8 data are from "The World's Sailplanes Volume II" published by the OSTIV in 1963.
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Old Aug 18, 2012, 11:20 PM
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These pages of HP-8 data are from "The World's Sailplanes Volume II" published by the OSTIV in 1963.
Thanks. I made copies for my collection of HP-8 data.

I'll probably redo my drawings. Looks like a cleaner version of what I worked from. Slightly different at bottom of fuse which bothered me on the first drawings.

Edit: Might be different since flaps and spoilers are not shown I wonder what both drawings used as a source.

Pete
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Old Aug 19, 2012, 12:06 AM
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From "The World's Sailplanes Volume II" Editor's Technical Introduction:

"The data presented are those sent in by the designers or representative organizations. They were not blindly accepted by the editors and in many cases were returned for revision. Sometimes the revisions never came back to us, which explains some of the gaps in the data. However all the data published are the designers' data and therefore only as accurate as the designers. Most of the performance data are calculated, and there is no lack of optimism in this book."

This seems to indicate the source was R.E. Schreder and what he sent to the editors of the book.
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Old Aug 19, 2012, 02:24 AM
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Originally Posted by Richard N View Post
From "The World's Sailplanes Volume II" Editor's Technical Introduction:

"The data presented are those sent in by the designers or representative organizations. They were not blindly accepted by the editors and in many cases were returned for revision. Sometimes the revisions never came back to us, which explains some of the gaps in the data. However all the data published are the designers' data and therefore only as accurate as the designers. Most of the performance data are calculated, and there is no lack of optimism in this book."

This seems to indicate the source was R.E. Schreder and what he sent to the editors of the book.
And considering that the HP-8 set world records while he flew it and then some more records in the hands of Moffat the performance data is probably realistic.

The drawings are good enough to make a recognizable model from. Funny, I don't remember the canopy being transparent over the wing but I'll model it that way.

Thanks again for the comments.

Pete
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