# Thread: Huge R/C Jet Structural Failure

1. ## Re: Huge R/C Jet Structural Failure

Most RC models are overbuilt and will easily survive a pitch-up like we see in this video. This particular model appears to be built extra light, which means less strong. Take a look at this snip; the former looks to be very minimal (made of small sticks) and the scatter of pieces in the air also seems minimal and looks like small sticks.

2. ## Re: Huge R/C Jet Structural Failure

Maybe it was made for a movie. And the pilot just went too fast.
It's all speculation.

3. ## Re: Huge R/C Jet Structural Failure

From this prospective those sticks look small. But once you look at the size of this fuselage you see maybe not so much. You should see the wood in my wing. I bet from this prospective those sticks in my wing would look as small.

Inside my wing.

4. ## Re: Huge R/C Jet Structural Failure

Looks like the front fell off

5. ## Re: Huge R/C Jet Structural Failure

Rigorous design standard: well for instance it's designed such that the front doesn't fall off.

Classic!

6. ## Re: Huge R/C Jet Structural Failure

I found my notes for dynamic scale modeling. From Al Bowers dynamic scale model article, Sport Aviation.
For 1/4 scale the weight should be 1/64 of full scale.
I don't know what it is for half scale, don't have the article any more.

7. ## Re: Huge R/C Jet Structural Failure

Originally Posted by BBerson
I found my notes for dynamic scale modeling. From Al Bowers dynamic scale model article, Sport Aviation.
For 1/4 scale the weight should be 1/64 of full scale.
I don't know what it is for half scale, don't have the article any more.
1/64 is (1/4)^3
If the scaling factor is linear that work out as (1/2)^3 = 1/8 of teh weight for a 1/2 scale plane. A half scale Gripen model should then weight in at about 1000kg! Not qute sure if the regulatory bodies would underwrite the desing of such a model.

8. ## Re: Huge R/C Jet Structural Failure

Originally Posted by Jay Kempf
It amazes me that people have the money to waste on almost full scale models.
It amazes me that there are people ignorant enough to think that building scale models is a waste of money.

9. ## Re: Huge R/C Jet Structural Failure

It amazes me that there are people ignorant enough to think that building scale models is a waste of money.
When these scale models cost tens of thousands of dollars, I guess one must describe or define...waste of money.

10. ## Re: Huge R/C Jet Structural Failure

I would have loved to have had that model 20 years ago in Europe....fly it out over Eastern Europe or East Germany. Of course, I would want it to hold together. What was that old hit song...a gal "Nena" and something about a balloon that started a war? A model like that would have started a war, I bet.

Derswede (Who was travelling in that area during that time)

11. ## Re: Huge R/C Jet Structural Failure

Originally Posted by N8053H
It amazes me that there are people ignorant enough to think that building scale models is a waste of money.
When these scale models cost tens of thousands of dollars, I guess one must describe or define...waste of money.
Depends on your perspective. To me it's a waste because I could build a "real" airplane for that kind of money and effort.

But to each their own. If you have the money, spend it on what you want.

12. ## Re: Huge R/C Jet Structural Failure

It amazes me that there are people ignorant enough to think that building scale models is a waste of money.
"Almost full scale" Sheesh.

I have been more than a little bit involved in the RC world over the years including two businesses. Seen lots of money blown and lots of engineering time directed towards model airplanes. Designed, built, flown all manner of model airplanes including scale stuff and still have the equivalent of a whole hobby store in the shop. Seen the rise of jets, weed whacker motors, electrics, composites, camera gear, CNC, autopilots leading to the term "drone" becoming so common it has becomes sickening. Also been involved in full scale. That vast majority of people playing with model airplanes would love to be playing with the real thing. So for someone to put the economic equivalent of a good used Cessna in the air and at a ultralight weights that is hazardous to operate as was demonstrated is to me some misguided talent and budget. At least the Cessna is built to some known safety standards and the operator most likely has some training. And don't think I am naive enough to think even a small model airplane isn't deadly. Been hit by some pretty pointy nosed competition sailplanes in the past.

The guy can blow his money any way he wants. But looking at the construction photos the breakup was built in. Glad is didn't come down in a crowd, on a road, on a house, on a kid.

13. ## Re: Huge R/C Jet Structural Failure

I don't see how it could cost \$100k unless someone hired a crew to build it.
I am guessing something like \$10k for the engine and radio, and not much for the plywood etc.
I am guessing it was a group effort where some guy builds the retracts, another installs the engine, another builds the wings, etc.
You could see the team at the flight event. Much of it should be reusable.

14. ## Re: Huge R/C Jet Structural Failure

Originally Posted by BBerson
I don't see how it could cost \$100k unless someone hired a crew to build it.
I am guessing something like \$10k for the engine and radio, and not much for the plywood etc.
I am guessing it was a group effort where some guy builds the retracts, another installs the engine, another builds the wings, etc.
You could see the team at the flight event. Much of it should be reusable.
\$30k min but possibly double that depending on how they went about sourcing and building. Those retracts alone would have been pricey or take a bunch of time and equipment for someone to cut out and fabricate or however they were done. Think mountain bike level stuff but more likely custom CNC. Big models aren't like small models. Almost everything is custom. Servos are huge and a lot of them. Lots of subsystems most likely triggered by servos. Not sure what motor but it would be at least 50# thrust for it to accelerate the way it was and climb the way it did at over 200lbs if that stat is true. When jets were new there was always someone building a 1/4 scale F14 and those were around \$50k due to engines and all the custom CNC stuff. And those were only about 8-10 lbs of thrust way back in the day. Engines have gotten more numerous and there are larger versions but they still ain't cheap. I just don't understand why they went sticks and balsa sheeting. Not the norm anymore. Most people just carve stuff out of foam and wrap it in a little glass and either dissolve out the guts or turn it into a plug. Guess some just don't like composites.

15. ## Re: Huge R/C Jet Structural Failure

Well, it was probably intended to look scale yet be ultralight. Like the Loele 51 (ultralight P-51 replica)