Firehawk

[erich]

Anyone ever build a plane called "Firehawk" by: John F. Clarke? It's an ALL WOOD, full house (rudder,elevator,aileron,flaps,spoilers) 125" glider. Has a modified E205 airfoil. A flying weight of about 90 oz and wing loading around 10.3. Have a copy of the plans and am hoping to make this a next project. Looking over the plans I get the impression this is one, very well designed, plane. Any info will be used, perhaps not wisely, but gratefully.


erich

[Guz]

Have a link? Photo?

Sound interesting.

[erich]

Only link I got is where the plans were purchased "RC Store".

http://www.rcstore.com/rs/general/listproducts5.asp?catid=32&catego=PL

Here's the add:

fsp04861
Firehawk
An unlimited-class sailplane by John Clarke that's the last word in design technology. Using a modified Eppler 205 airfoil, the Firehawk rides thermals with aplomb, and its spoilers allow spot-landing on a dime. Not for the beginner, this model uses advanced building techniques that require some fundamental scratch-building experience. WS: 125.5 in.; L: 56 in.; Area: 1192.5 sq. in.; 4 channels; 3 sheets. LD4
$ 29.95



erich

[drCarter]

The E205 was hot about 25 years ago. It should still fly nice though.

[erich]

drCarter

E205 worked pretty good on a Sagitta 900 of mine, so I agree with you, it probably will fly nice. Of course that is, if: the laws of aerodynamics haven't changed too drastically.

erich

[Whorges]

Erich,
I've been building a sagitta 600 with eppler 205 foil. You guys recommended extending the top sheeting to prevent scallaping contours in the monokote.
Are you going to do this? Do you plan to use turbulators?

I extended the sheeting to about the 60% cord. I haven't finished the build yet, but I'll let you know how it flies when I do. Unfortunately you build 10x faster than I do so you'll be done by then.

Happy building,
Whorges

[erich]

Whorges

This is a fully sheeted wing. But I may just use 5/16" rib caps. Have a lotta trouble gluing down big areas of sheeting. From LE to back of spar will definitely be sheeted (but, like you, may extend beyond spar a little also). When you say turbulators, if you're referring to thin strips of tape, going the full span. I may do that, but probably not. Did put a 1/16" wide striping tape (full span just above spar) on my Windsong, which seemed to help at low speeds. This will be a scratch built plane, so may take a little longer, especially if I gotta, cut, all the ribs, by hand. Will probably finish the last kit I have in stock (a Windsong) before going to the Firehawk. Unless I can find someone to laser cut the ribs for me. Good luck with Sagitta 600, bound to be a great flyer.

erich

[trident58]

Erich,
Look at www.kitcutters.com if you want someone to laser cut the ribs for you. The problem with those older plans is that they are not done by CAD, so the rib profiles neeed to be converted to cad before they can be laser cut. I almost had them cut the ribs for the Durex V, but I ended up cutting them myself with a Dremel saw. Cutting ribs is a pain, but it's not as bad as everyone makes it out to be. It took me about 3 hours to cut and sand all 56 ribs. The key is transferring the ribs to the wood. I made photocopies of them, placed the copies face-down on the wood, and then ironed them with my covering iron set on high. The heat melts some of the toner onto the wood, giving you real nice cut lines.
Jon

[erich]

Jon

Have been in contact with kitcutters, they say May will be next delivery date. Like, the photo copy thing. Scratch built a large canard a few years back, made paper templates (layed paper over plans and just traced outline) of ribs, then cut those out with scissors. Placed templates over wood and traced with pencil. THEN cut out ribs with exacto knife and finally did some sanding. After all that transferring am sure the airfoil I ended up with, was an original one (for better or worse). Did you do the same (photo copy transfer thing) with formers and fuselage sides? Have a Dremel tool but am not sure what you mean by Dremel saw? Keep up the posts on your Durex V, look forward to them. Thanks

erich

[histarter]

drCarter

E205 worked pretty good on a Sagitta 900 of mine, so I agree with you, it probably will fly nice. Of course that is, if: the laws of aerodynamics haven't changed too drastically.

erich
Great comment. I take it as a toast to the founding fathers!
Only the people have changed - demanding aerodynamics to change to their percieved needs. :D

[erich]

Yea.... I got a chuckle out of my comment, also. What really bugs me though is: have now built 4 classic planes (Camano, Mirage, GL, Oly II) and haven't flown any of them. Where the....is our January thaw?

green air
erich

[trident58]

Erich,
I only used the photocopies for the wing ribs. The formers for the Durex where all rectangular, so it was simply a matter of measure and cut. The fuse sides where too big, so I drew a centerline on the plan view and on the wood, then I picked certain points along the datum line, measured the distance to the edge of the part, and then transcribed it to the wood.
The Dremel saw I'm referring to is their compact scroll saw. I don't know if they still make it, but it was their model#571.
Jon

[cynjon]

What really bugs me though is: have now built 4 classic planes (Camano, Mirage, GL, Oly II) and haven't flown any of them.

Unacceptable...for your punishment you must send me the Camano at once--you need to make room for your Lovesong build! ;) :p

BTW, is it just me or does the Firehawk look a lot like the Mirage?

[erich]

Sorry cynjon it's you, the Firehawk is much more like a Windsong. It has no polyhedral and only a few degrees dihedral. While the Mirage has no dihedral and a lot of polyhedral. Sounds like gibberish doesn't it? But you are right about needing room for the Windsong. Would send you the Camano except it's my favorite. And not being able to fly it, is punishment enough.

erich

[Ray Hayes]

Yea.... I got a chuckle out of my comment, also. What really bugs me though is: have now built 4 classic planes (Camano, Mirage, GL, Oly II) and haven't flown any of them. Where the....is our January thaw?

green air
erich


Erich, You had me fooled, I would swear you did the Sky Bench Challanger build.

Ray Hayes

[WimH]

Erich, You had me fooled, I would swear you did the Sky Bench Challanger build.

Ray Hayeshe's flown that one already if I'm not mistaken...

[erich]

Ray

Nahh, your memory is just fine. I did build a Challanger and also a Scooter, both of which have been flown. And both of which (IMO) are classics, especially the Challanger, which could be the poster boy for the word classic. Since those two were finished we've gotten quite a bit of snow here in the northeast. So have been stuck inside, building, but no flying. Your query however gives me the oportunity to again show off the beautiful Challanger.

erich

[erich]

So now here I am stuck, with nothing to do. Am trying to decide on a next project. The Firehawk and also a Saggitta XC are prime candidates. Have been leaning towards the Sagitta, since I do have a rib set for it, whereas the Firehawk would have to be 100% scratch built. Kinda like the idea of building a 14' wing with a 13" chord, and a spar that is 1 1/4" deep....yikes!

erich

[Gliderguy]

You're a dynamo erich!! :D

I'd have to be resting up from all those builds. Almost have to rest up after all the build threads you have going. :D

Keep up the good work. Hope you get out soon (nothing but rain in this part of the country).

[erich]

Gliderguy

Dynamo, shmynamo...I need to get a job! Maybe watchmaking! Only thing keeping me, even half sane, is building these planes. Yea... were getting rain now too, last 2 days, light rain. Hope it melts most of the snow. Found a great, recently capped landfill, for flying, 3 miles from my house.

erich

[Matthias89]

hey erich,
The last time I asked you, you only flow the Challenger ones. So how does it fly? :rolleyes:

[erich]

Sorry Matthais89, still have only flown it that once, so can't say to much about it. It can be flown quite slowly, although controls aren't quite as responsive then. If I was to build it again, would put the spoilers in. Even with 90 deg flaps it still comes in somewhat shallow. Guess it just doesn't want to land.

erich