Title said that it broke the sound barrier, but that's BS. Has any RC jet or plane created the moisture con trails that are produced from fast flight? I wouldn't think so, but with the right conditions and plane [X(]?

I think that photo is a fake, but yeah under the right condisions even race cars will creat con-trails, so I am sure RC planes have.

On Fake photo, yes, that photo is obviously a fake. The original is with a Hornet, see atatched. I've seen this photoshop with helis, superman, etc.

This is not a condensation trail. It is a Prandtl-Glauert singularity (often just called vapor cones.) These require close to sonic speed, so no, you won't see this as I am not aware of any model that can get to the 0.8 mach speed where you start to see this formation.

However, I have seen one model plane, and one plane only, create what appeared to be condensation on the top of its wings during high G pull ups (not the same as vapor cone.) However, the tank vent tubes were also in that general area. It is unclear if what we were seeing was fuel being sucked out of the vents or if it was indeed condensation of water due to the low pressure area on top of the wing.

If any one has confimed a model that can do this, I'd like to know the model... cause I'm gonna want one.

I have seen it on the wings of fuel drag cars at the strip. The rear wings generate a tremendous amount of down-force to keep traction at 300+ mph and accelerating.

Bruce, I'm pretty sure what you are seeing on the top fuel dragsters is condensation due to a low pressure area in air that is well below the speed of sound. While still totally cool, this is different than the vapor cone shown in the post which only occurs at speeds close to that of sound. However, the mechanism that created the vapor from the top fuel wing is what I assumed might have happened to the model plane I saw (possibly) do this.

I've seen that same picture of the F/A18 Hornet. I think you can find it on wikepedia. The "vapor cone" is an amazing phenomenon that (to my knowledge) has NEVER been photographed THAT PERFECTLY in formation around a plane. It's an incredible thing when the air/humidity around the nosecone of the craft gets compressed to the point of BURSTING into a MASSIVE cone. And yep, it only happens near the speed of sound and the air density/humdity has to be JUST right for it to occur this beautifully.

I've seen some pretty fast planes (my friend's 109" P51D Scale will burn a low pass that's been clocked over 120mph) and last weekend I saw a competition 180"(?) Edge260 do a pass at well over 80mph and the throttle was barely 2/3 open (both were EXTREMELY IMPRESSIVE!!!!) > and BOTH were somewhere above "TOO DANG FAST!" for me flying

The fastest little bugger I've seen (granted I haven't looked for ULTRA-speed planes!) has been that Mig on the rcuniverse homepage that can pull fly-by's at 130mph!!!!! (however, launching with the "bungee" was one of the strangest things I've seen in a LONG time Granted, it's a very valid way to get a plane flying, it just looks WEIRD!)

Fast is Fast. But "Vapor Cone" pegs the speedometer at "Ludicrous"

I flew in A heavy rain once, I guess it was leaving A vapor trail behind it??

I've seen it behind a car antenna, not going all that fast. It just depends on conditions.

That is a vapor trail, not a vapor cone. There is a big difference between the two.

That's called a "PhotoShop condensation phenomenon".

Even though that pic might be fake, its still funny, you got to admit it. I can't remember what this is called. but it can happen way below M1 but it looks like the sound barrier but its not, can someone name it for me, i think someone has already said it. I was at an a blue angels homecoming and they had a F-18 super hornet do fast fly by, it had a greenish glow around the leading edges of the wing, it was a night show when this happened, the annocers said that he was very close to M1, ( I would have loved it if he had broken the sound barrier in front of us, but he would have broken about every window there, but still would have been awsome

That Luscombe 8F Silvare, 85hp Continental with two very cramped fellows on board would be hard pressed to break 85 knots.

This is the technical definition "An F/A-18 Hornet at transonic speed and displaying the Prandtl-Glauert singularity just before reaching the speed of sound"

Here is the "story" about the luscombe: http://home.mchsi.com/~shoskins/fastluscombe.html

I had an awesome pic of a F-15 with a vapor cone that I took at an air show. I dont know how I caght it. But unfortunately due to a virus I lost it. It may be on a cd somewhere.

Speaking of speed...
How fast do those model turbine jets go? I was reading in the RCMW magazine about an American RC pilot that had broken the world RC speed record. He managed 365 mph with his glider!
I would have thought the jets were faster than gliders but apparently not.

Turbine powered models are often equipped with governors limiting their top speed to the 200~250 mph range. Many high powered turbine models are capable of flying faster than the airframe could sustain. Eventually they would simply rip apart in air without a governor and/or sensible throttle management preventing such an occurance.

Hotline gliders, on the other hand, are vastly lighter weight and are able to achieve staggeringly fast speeds only during precise atmospheric conditions. Their much higher strength-to-weight ratios (made up term?) allow near 400 mph bursts during dynamic soaring.

Is that only in a dive?

A turbine can never break the glider speed record in the states as the AMA limits turbine speed to 200MPH.

On the vapor, we can't get the singularity because no model I am aware of can obtain speeds near that of sound, so a vapor cone isn’t going to happen. But has anyone actually seen vapor formation like on the top of wings during high G maneuvers?

I used to watch Dad, "Hitting the Break", back when he was flying Interceptors. He would appear over the field, and while performing this maneuver, the boundry layer controls would be moaning, and all kinds of vapor vortices would be visible. This was a hard pull, and there were lots of Delta pressures on the flight and control surfaces. One of the reasons for lower speed low altitude vapors are from these controls, and they use compressor bleed air, and the temperature differentials are very high. I have seen the wing vortices on prop driven planes too, but these usually occur when the humidity factors are just right .

Bill, AMA 4720
WACO Brotherhood #1

To answer your question John,YES! My youngest brother had a House of Balsa AT6 that was a 10 sized plane,with a OS32 helicopter engine in it ,that was fast enough to creat the twin vapor contrails off each wing tip in flight when doing a sharp turn. The first time it did it,we all yelled LAND NOW! your covering just ripped off. On inspection after he landed,there was no covering missing. We had him fly it again,and low and behold,it did it every time he made a full power high speed turn. I dont recommend doing it to many times as we found out one day,it over stressed the wind dowl and snapped the former in two,causing a very nice,fast and deep divot in the runway!

So yes it is possable to create the contrails with a prop driven plane,but not recommended. A bit more info on the plane here to help everyone under stand how over powered it was.

Plane full up weight ( plane,motor,fuel,and radio gear) weighed in at just under 2 pounds

Wingspan was 32 inches

Fuse length was 29 inches

Prop was a master airscrew 8/6

No landing gear,was hand launched holding full right rudder and aileron,landed on belly in grass after engine was off.

Hope this info helps

Art

Like this one? A Tornado performing a stall maneuver.