New British Plane for OTS%21

Ian, et al: The plane I'm planning to build is the Icarus Jr. Know anything about it?
Bob Z

Bob, yes. Seem to recall the original had a Yulon 29 or 30 in it, can check. The Icarus Senior was a streamlined Taurus, and the Icarus Jun. was a scaled down Senior. Designer John Coasby, an Aeromodeller staff draftsman at the time. Do you have the plan? Can get one for you and swap for one of your Coon Dog plans if you'r interested. I guess the streamlined planked fus will be a labour of love!

Bob,

It sounds like you are already getting some help from Ian, but I am going to cut in here anyway.

I have not had access to the April 1951 issue of Aeromodeller where the Icarus Junior and Senior were published. I do have an Aeromodeller Plans Service catalog from the early 50's that shows a small photo of the large Icarus.

The Junior version was for 5 cc, had 42 in span and 325 sq in.
The Senior version was for 10 cc, had 67 in span and 780 sq in.

As Ian explained, they have a round fuselage cross section, swept leading edges on wing and tail with semi-eliptical trailing edges. Upright engine with a spinner. The landing gear does not show in the photograph, but I would assume it is a fuselage mounted gear or might even be a drop-off gear. Maybe Ian could enlighten us on this.

I know Rusty brown has flown the Taurus at VSC. I do not remember if he has ever shown up with the large Icarus, but it is the kind of airplane he would build.

It also sounds like Ian has plans available. Plans are on the so-called X-List and should be still available from Nexus Plans Serice in England or from Bob Holman Plans here in California, assuming San Bernardino has not burned up yet.

What sized modern engines would be suitable for the Icarus planes?

I guess consider engines of about the same weight and power and rpm range as the original engines. For the Senior look for about 0.9bhp and max weight of around 16oz +/- a bit. For the Junior, about 0.35-0.4bhp and weight of about 6.5oz. +/- a bit. Older cross flow 60's, ST51, O.S. 25? for the Junior?

You've not been chcking my website have you - the Icarus was up there recently.

I'll put that weeks back for a day so that you can see the article - so capture it whilst you can!

I'll reload this weeks tomorrow!

Tony

(It's the articles site below)

http://www.the.elmores.btinternet.co.uk/stunt/_cat001.html

http://www.the.elmores.btinternet.co.uk/articles/articles_cat.html

Keith, Ian and Tony - thanks for the information. As it turns out, a fellow I used to work with sent me the plans from England and, I think he got them from "X".
Looking with a magnifying glass, the engine on the plans I have is an ETA .29 rear rotor. Interesting as I found one of these in my "stuff" (I have lotsa stuff). Anyhow, whenever I build an OTS plane, I try and use the engine shown on the original plans. I did this with my Scared Kitten, Screwball and Viking. Here's another opportunity. The ETA is new so I must break it in. Some people I know used these in speed in the early 60's so some mods may be in order. Any suggestions?
Bob

LAST EDITED ON Oct-29-03 AT 01:23 PM (CST)
 
And the article may be of interest to Keith.

I walk past xlist plans everyday on my way to the railway station....

http://www.the.elmores.btinternet.co.uk/stunt/_cat001.html

http://www.the.elmores.btinternet.co.uk/articles/articles_cat.html

I've just realised that there was something wrong with my last update of the articles site - why didn't anyone tell me - I'm redoing it now.

Also has Firebrand and Juggler - both OTS valid!

TOny

http://www.the.elmores.btinternet.co.uk/stunt/_cat001.html

http://www.the.elmores.btinternet.co.uk/articles/articles_cat.html

Sorry, Tony. I was able to navigate to all these articles at first. Then, when I couldn't, I just thought it had to be a "work in progress". 'probably happened to others too. Anyway, thanks for posting the articles.

SK

Bob, check your email I just sent you a jpeg copy of the Aeromodeller article of April 51.
One placed 4th in spirit of SAM at SAM 35 Gala this year. Flew very well on McCoy 29(I think that it was an early superstunt).

I think I remember Rusty Brown saying he had a mold for the top of the Icarus fuselage. Probably the big one, but I'm not sure.

Keith - you were right about the drop-off gear. Mike Bennett (THANK YOU MIKE!!) sent me an electronic copy of the plans and they are so clear that I can make out detail that I did not see on mine. I have decided to build it EXACTLY per plans, right down to the wing (attached with rubber bands) and the external lead-outs. I noticed that the tail section is not only built up but has capstripped ribs. That should keep me busy. The engine will, of course, be the ETA .29. As I did on my Stunt Rocket, I will use a screw-on clip to retain the landing gear.
Suggestion are welcome!
Bob Z

Bob,
see your email again (different isp this time?)I have sent the article originally intended.

Regarding the engine, I am not an ETA specialist but I do know that the first ETA 29 test in Aeromodeller was in Sept 49 and this was the G.P.Model A with a recorded output of .370 BHP!(a pussy cat) Later production went on at least into the 60s (someone else will know the final dates) and Model V1c more than doubled this output, dont know which one you have.

Mike - received you 2nd e-mail. Thanks for the article. I really like to compile as much info as possible when I start a project. Check out the picture I posted in response to Ian.
Bob Z

Checked my Icarus Jun. plan, you are quite right Bob it shows an ETA29, not too sure of my mks. but think it's Mk1 or 2. Knowing I've seen this profile with Yulon in it checked further and found the Yulon 30 model was the Flicka, in the 1949 Aeromodeller Annual. It has very similar side profile to the Icarus.
Concerning engine mods, it may depend on what mk. your ETA is. All the early ones would be satisfactory as-is, they preceded our knowledge of advanced timing for racing engines etc. Even the latest Eta made, the Mk6, is probably o.k. although you would get a more exciting ride! If it's relevant, if you get the right Mk6 you could have a c/case with holes each end of the exhaust to mount a silencer.

Ian - Mine has a silencer. What MK would you say it is?
Bob

Mike & Ian - you fellows obviously know your ETAs. What can you tell me about this one? (found it in my stuff)
Bob Z

Vereee interesting. Not a factory conversion I suspect. Is it an O.K. timer? Whichever one it was that had the spring loaded ball to locate it. The engine could be a Mk5. If the head bolts are closer to the centre than your Mk6, it's a Mk5.

Hello, Ian, Mike and everyone!
After a closer look at the timer, it appears to be from a Super Cyclone or Anderson Spitfire. The conversion is so well done that I assumed it was from the factory. Should be interesting to see how it runs. It will, of course, wind up in the Icarus Jr.
Bob Z

Hi Bob. Your Icarus Jun. will have an ignition engine then? the original was glow, so be prepared for a little weight increase. But what a great project. Looking at the photo of the engine, the headbolts look like it's probably a Mk.5, so no shortage of power, especially if no muffler. And glow fuel of course. Even a little nitro!

Hi, Ian - I think it would really be interesting to fly the Icarus Junior on spark ignition. Regarding the weight, yes there would be an increase but not as much as might be expected. I've been flying spark ignition for the last 10 years. Careful experimenting has led to some interesting results.
The engines are completely reliable - I've NEVER had a non-start, and here are some of the reasons.
1st: I've had the best runs with gasoline and castor oil. Keep in mind that this requires one-third the amount of fuel. The higher combustion temperatures keep the plug very clean.
2nd: I've converted from 3 AA alkaline cells to 3 NiMH rechargeable cells which weigh one-third. I get about 8 flights on a charge.
3rd: I found an inherent weakness in virtually all the old-style coils and corrected it.
4th: I clean my points and plug about every 25 flights.
That' it - no magic and lots of enjoyment!
By the way, the tank/ignition compartment will be large and accessable such that I can convert from glow to spark and compare the two.
Bob

Hmmm. I'll be asking advice when I get my ignition project more advanced. Have 75% complete Easy waiting in U.S.A. for me to complete it.

Ian,
what size easy are you building, and where are you putting the tank?
Plan shows it in the wing but thats a long fuel draw and my 36'' version has little space between the engine and the leading edge.

Hi Mike. It's the biggest, 45"? For one of my ign. Frog 500 repros. I'm trying to keep it light. Tank is a bought item from RSM, and it's really a bit fudged. Really needed a custom tank, but time was limited. It's in the wing, so quite a long fuel draw. Should get a real 4/2 break!!

Bob, you lucky man. It looks great. I say it's a 6c. There was an article on ETAs in Model Engine World. It reckoned although many people think the change from 6 to 6c (there was no 6b?) happened with the introduction of the silencer lugs, this is not the case. The factory started calling them 6c before the lugs came in. Possibly the 6c had the transfer ports angled with milled channels smoothing the flow into the cylinder. So if you have the lugs it's got to be a 6c. The good news perhaps is that with the silencer fitted you will still have adequate power, equal or better than the original engine. Plus a little weight.

yes, very nice - mine's a 6c too but I do not have one of those neat little silencers. Anyone out there got a spare one?