Profile Bomarc IM-99/CIM-10

[burkefj]

Well, f86esabre(steve) asked me a question about bomarcs and that got me thinking about doing one finally, it's been on my back of the burner list for a long time, I finally dug around through my old Highpower Rocketry stuff, and found a blueprint from Boeing done in 1960.

Surprisingly there is a dirth of bomarc 3 views on the web for some reason. My dad started at Boeing in 1958 on the Bomarc, then worked on B-52 tail gun radar, minuteman for 20 years, and then IUS, so the bomarc always held a soft spot for me, since I was a kid, I did do a scratch built rocket back in the mid 80's.

I'm thinking of an X-form to keep it long and light and to get enough surface area, with full flying tail only, and a pusher, maybe in a rocket pod so I could do vertical rocket launch/glide or pusher like I've done with my natter and X-15. If I get really motivated, I might do twin pushers in the pods, and rocket in the rear, vertical launch transition to electric, but we'll see. The problem with profiling this is the mounting of the ramjet pods, they go into the lower fuse at a 45 degree angle and will take most of the landing impact, I'm thinking of doing them as xforms also, and need just just figure out a good solid mount into the fuse.

More to come, I believe Steve is/was going to do a DF or pusher based on a tube, so hopefully I won't steal any of his thunder or duplicate what he wants to do.

I'm thinking of doing it in the white color scheme, to save a little weight, and because I never see that done as a rocket, and since I've already done a black version.

The strings on the rocket body are the recovery system, that I found to be the best, a horizontal recovery, it prevents totally any shearing if you have early or late ejection.

Frank

[Hepdog]

Interesting build idea. I'll be watching this one closely.

I noticed you have a CF105 model hanging from your roof. Are you aware of the sorid history of the Arrow and the Bomarc replacement? Diefenbaker - spit potouee... :censored:

[burkefj]

Yes, I've got a movie and book that details it well, ignoring that part of the history, I still think the bomarc was pretty effective, at least according to my father, it's interesting that boeing does not release any information about it...

Frank


Interesting build idea. I'll be watching this one closely.

I noticed you have a CF105 model hanging from your roof. Are you aware of the sorid history of the Arrow and the Bomarc replacement? Diefenbaker - spit potouee... :censored:

[tpfing]

I'll be watching this one Frank. Very interesting.

Tony

[burkefj]

Here is what I got done tonight, I've been worried about how to mount the ramjets without them breaking on landing, I decided to do an xform, with carbon rods that go through carbon plates that will be laminated on either side of the fuse, the force should be a shear force upward and I think this will hold, especially if I can keep the weight light, I show some of the pics of the first pod, unsanded, and the top and side view templates....

I went with a 48" length and 21 inch span, slightly upsized, but not by much.

Frank

[burkefj]

Here's the parts all layed out on one sheet of 27x39 depron...

Frank

[f86esabre]

All right Frank, your doin the Bomarc. The Ramjet connection to the fuselage looks good for your version. I am worried about my full version though. I plan on useing a 70 MM fan so I think mine will be around 2-3 pounds. I thinks the the nose will take a beating after the ramjets hit the ground.I also want to make the wing tips functional. I will probably run tubes from the wing tips to servoes in the body. My friend with the rocket has made his out of glass and lots of epoxy. Strong, but heavy. I will use your CG to start so I look forward to your results.
Steve

[burkefj]

Got a little more done before dinner tonight, I need a rest, dont' know if I'll do more tonight:)

I taped the ramjets on a little too far forward for the pictures...
And, I realized the wing is in the upper 1/4 of the fuse, so I couldn't do a normal xform, had to have the upper section higher, I placed it level with where the bottom of the normal wing would go, the wing has a pretty good arifoil on the real thing, the airfoil is as deep as the tunnel...

Only looks funny from the very top where the nose looks a bit short since I had to cut it to stop where it hits the fuse, but I don't think it looks too bad.

Frank

[f86esabre]

Frank, I am thinking this is going to be a good flyer. Looks like a lot of lift area. Do you think elevons will have enough control force?
Steve

[agriebel]

You must buy your depron by the truckload! Which motor are you going to use?

[Speedo125]

That is really looking good Frank. As a product of the 50's, I have a bit of a soft spot for the Bomarc myself. I'll be watching your build.
Thom

[burkefj]

Thanks Steve and Speedo, yes, I'm pretty sure the tailerons will be effective, the winspan is almost identical to my X-15, it's just a bit longer, and will be a similar weight, and it flies really well with just tailerons, given a lot of throw especially.

As for motor, I've ordered a ls parkjet, and I'm going to do a 24mm motor pod in the rear, so I can do a rocket launch, glide return, or plug in the parkjet into the rocket tube and fly it as electric, just like my natter and X-15 are now, actually use the same exact electrics for it, just use velcro to hold the wiring in place when I swap them. I had to scavange the purple peril I was using for the electric system when I built my X-3:)

I think my AUW will be around 11 oz rtf hopefully depending on balance needed. I finished one ramjet pod and it seems pretty sturdy, I made the carbon rods slight further out on the other ramjet pod so they will cross over and touch the other ramjet rods and I can get a glue joint there also.
The plane with carbon spar, and tailerons without electrics is at 4 oz now. Add another ounce for glue and misc, three for motor, prop, servos, receiver, and 3 for 1320 pack It should be close.

I think this size and construction is a pretty good tradeoff for wing area versus weight. Hopefully I'll have it fitted together and glued today and start some of the decals and lines, then I'll have to wait for some glide tests and the ls motors to come it at hobby lobby.

Frank

[burkefj]

I made some more progress, most of the markings/lines in place, and dry fit together, need to finish the "stainless" monokote on the rear of the other ramjet pylon, (there were bare stainless portions on the lower rear fuse, lower rear wing, and rear of the ramjets) and glue the fuse halves together, then do some test glides before I install equipment and pods. Then paint the nose cream colored. AUW for airframe and motor mount is 5 oz so far, I think I'll be in the 11.5-12 oz rtf weight. LS motors aren't due now in HL till jan 9.....I decided to do a 24mm pod and launch lug, so I can ground launch or fly electric.

Frank

[burkefj]

Here's some Bomarc erection and launch sequences from "Armored Sky" that a friend of mine made for me a long time ago.

http://www.youtube.com/watch?v=U106IfoS4pM

[burkefj]

Plans are posted here, along with a shrink of the boeing blueprints, I have done glide tests and marked a conservative cg on top of that, but I'm stuck waiting for a parkjet motor to get into HL to do test flights to confirm.

http://www.rcgroups.com/forums/showpost.php?p=11285180&postcount=212

[burkefj]

I got tired of waiting for HL to get the lspj's in, so I scrounged the purple peril from my X-3 and will put the PJ in that plane, it can use extra speed. I wired up the electric bundle to the removable rocket pod, and set the CG.
I decided to do the first flight without the ramjet pods since it would make landing easier in case somethinig didn't go well. It was a bit windy this morning but good enough. I had pre-set four clicks of up elevator and one click of right aileron, I had set the throws at 125% on the futaba radio.
AUW was 10 oz.

Toss at 65% throttle and she took off just fine, removed the one click of right, and it was perfect, roll rate was a bit sluggish, but pitch was perfect, just a hair sensitive, the way I like it, loops you could force it to mush through very small, or keep them big and round. It tracked really well, but didn't need much elevator to pull around till you were banked pretty far. Slow speed with power on was pretty slow considering the wing area, glide was not bad, but it is not a floater, it looses elevator pitch effectiveness right at the flare point when really slow, a little power keeps effectiveness.

The only problem I had was that I tried to grease it in, and right at the last minute I had a gust of cross breeze blow it right into my stomach, I was so surprised, I didn't even try to catch it:) Pretty funny I'm sure if you were watching it.

So, success in hand, I went home, mixed up some 5 minute epoxy and mounted the ramjets and the launch lug. Everything looked good, and my CG stayed right about the same, maybe slightly less nose heavy. AUW was 12 oz. Unfortunately, my good lower handlaunch spot was gone now with the ramjets so I have to underhand toss. I checked the CG with it on the ground, it is slightly back from the front of the ramjets, I did some carpet landing tests, and it seemed that a slightly nose up sliding landing, would only tip over at the last minute and i wouldn't need anything to keep the nose elevated and from digging in.

Back to the field. Underhand toss at 70% throttle climbed right away, in fact I had to remove the four clicks of up trim, and it was perfect, so very neutral build. Flight performance was very similar, except on slow split esses, you have to watch that it wants to flip right side up if you don't pull right away, due to the weight of the ramjets on the bottom. I upped my throws to 140%, elevator stayed perfect, roll rate was better, nothing startling, but good enough for flying it like a bomarc. Flew it around and it looked great, came in for a landing, got it pretty slow, gave it a shade of power and it touched down and tiped forward and stopped. No damage:)

I finished the painting, and will try to get video this weekend if possible. The rains held off till I finished, it was a good morning.

Frank

[jetcaptain]

Way to go Frank, sounds like you had two great flights.

[burkefj]

I was able to get video this afternoon, thanks to my daughter, AND was able to try a single rocket flight on an aerotech E-6RC reload with an 8 second burn, it was perfect, and the glide was very well behaved, I had a very good landing, considering I flew right through the heavy smoke and couldn't see the plane the last three seconds of the flight, I just kept the sticks as they were since it was in a good position and it settled perfectly. I also got in a flight on my X-15 with the same motor, I'll post the videos shortly.

Frank

[burkefj]

Here is the video from this afternoon with rocket and pusher power!

http://www.youtube.com/watch?v=epsCz1gt4Gs

[jetcaptain]

Nice. Looks like it flies really well. Love the flip overs.

[race58]

I posted over at RP http://www.rocketryplanet.com/forums/showthread.php?t=2923 about your Flying Rockets and like I said over there I'm am very glad to have found them.
Really cool stuff. :D
Thanks
Ed

[burkefj]

Thanks guys! That really made my day.

I think the four neatest things I've experienced in the last two years which were things I used to dream about as a kid were:

1)Being able to fly a micro heli in the house
2)Doing touch and goes in my driveway where I grew up with parkzone
micro cessna
3)Flying an RC X-15
4)Flying an RC Bomarc

Frank

[Vethraxx]

Looks like there are plenty of bomarc fans here. I have a question. I am planning a balsa Bomarc RC with EDFs in the ramjet nacelles I noticed a discrepancy in the shape of the jets. This plan http://jetex.org/images/back_room/godel-030727/bomarc.gif has the shape most commonly seen in photos. But I also purchased "The History Makers" 1/47 scale model as a 3D reference, and I noticed the ramjet nacelles are shaped completely different. Anyone know why? Prototype vs service model? Just a bit of trivia I'd like cleared up before I build.

[tpfing]

Maybe these will help.

Tony

[Vethraxx]

This is the image of the Revell model 1/47 scale. The posterior of the jet is choked down and then flares out on the end. The anterior is very rounded, and less cone pokes through. Is it just a bad model?bomarc

[tpfing]

Vethrax, I'm not expert on the Bomarc except I just think it is a cool looking missile. The photos that I posted are photos of the real thing, not a model. It looks like the model exaggerated some of the curves.

Check here if you haven't already done so. Hundreds of Bomarc photos. Some good, some not so good. http://images.google.com/images?q=bomarc+missile&oe=utf-8&rls=com.ubuntu:en-US:unofficial&client=firefox-a&um=1&ie=UTF-8&ei=PwnASqzkHorj8QaI3aW8AQ&sa=X&oi=image_result_group&ct=title&resnum=4

Tony

[Vethraxx]

Thanks for the input, I have exhausted all google can show me on this subject. That why I was asking. Looks like I may have to track down a few old Boeing engineers.

[burkefj]

The Revell model has ramjets that are not even close to anything I've ever seen on a real bomarc. There were Two versions of the bomarc and they had different ramjets, the later version had more of a straight rear half of the ramjet tube, while the earlier had kind of a nozzle looking flare at the end.

This is a bomarc B plan from Boeing which shows the straight ended version, also note the two different versions had different wing locations on the body and the nose shape was slightly different also, look at different versions and you will see a different spacing between the wing trailing edge and the leading edge of the horiz stab. You can also look at where the ramjet ends, on some the ramjet ends at the beginning of the horizontal stab where it meets the body, on this drawing of the B model, they end well ahead of where the horizontal stab hits the fuse.

http://www.rcgroups.com/forums/showatt.php?attachmentid=2263415

Frank

Thanks for the input, I have exhausted all google can show me on this subject. That why I was asking. Looks like I may have to track down a few old Boeing engineers.