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bvmbandit
05-07-2018, 11:10 AM
I notice a large vapor cone around the circumference of the tail on my 1946 Champ the other day while flying. This occurs inconsistently and seems to show up at higher speeds. Anyone else flying the older Champs notice this? Does not seem to affect flight performance at all...

Thanks,
- Vern

cubdriver2
05-07-2018, 11:20 AM
I notice a large vapor cone around the circumference of the tail on my 1946 Champ the other day while flying. This occurs inconsistently and seems to show up at higher speeds. Anyone else flying the older Champs notice this? Does not seem to affect flight performance at all...

Thanks,
- Vern

I don't think you'll get any answers here, we fly Cubs and they don't go as fast as a Champ

Glenn

BC12D-4-85
05-07-2018, 11:47 AM
The speed of sound varies by aircraft. Unlike Cubs, you see Champs and Taylorcrafts before you hear them.

Gary

Waldo M
01-02-2019, 09:29 PM
Did you happen to have had bean burritos for lunch before taking off?

aktango58
01-02-2019, 10:42 PM
Wow, Where's Waldo? You sound like either one of them outlaw Jenklahoman's, or you been hanging around the guys on the North East! Watch them boys, they will make you laugh so hard you will split your gut!

Back to champs- is it possible this happens on high humidity days with temp and dew point close?

Lyn did not get it on film, but one time this fall my prop was causing vapor trails, and as soon as I started getting some speed my wingtips began creating them also as the air was disturbed by the wing.

The tail would compress the air as it goes around either side, creating the same effect. The need for high moisture and close dew point/temperatures would be the reason it is not consistent.

Glenn above, cubdriver2, flies lots of old stuff that gets passed by blimps, so would not have seen this happen:-P:-P;-)

skywagon8a
01-03-2019, 07:02 AM
aktango58 has the answer. There are two mile long lakes here which are side by side. One flat calm summer evening I landed on one of them and did a high speed step run for the entire length. When I climbed up and looked back the entire lake was fogged in solid. Then I went into the other one doing the same thing. It too became fully socked in. It was a very educational experience showing how the disturbance of saturated air can quickly change the situation.

CharlieN
01-03-2019, 08:24 AM
Interesting situation when you land on a lake in VMC, and the lake is IMC when you depart yet you departed in VMC conditions. That just might be an interesting short topic for thought in my VMC club.

skywagon8a
01-03-2019, 08:39 AM
While I can not remember who it was, but I seem to recall that someone told me that he saw me doing this and that the "fog" which formed from my prop had followed me the length of the lake. An interesting phenomenon to say the least.

I can also recall another instance when I was above a cloud layer when I saw a Lockheed Electra slowly descend into the tops. It left a wake behind it in the clouds which resembled the wake of a boat on the water.

GeeBee
01-03-2019, 08:42 AM
I notice a large vapor cone around the circumference of the tail on my 1946 Champ the other day while flying. This occurs inconsistently and seems to show up at higher speeds. Anyone else flying the older Champs notice this? Does not seem to affect flight performance at all...

Thanks,
- Vern

Since you are close go up to ATL on a high humidity day and watch the same thing on the landing jets. Especially off the corners of the flaps where the release of high to low pressure is great. Park in the State Farmer's market landing west or in the College Park Marta lot landing east. It's free.:)

CharlieN
01-03-2019, 09:01 AM
I had just never given thoughts to consider that contrails could be active to the level we see Microclimates. It is logical though that when the atmosphere is so close to tripping that just a light aircraft can do so. I work with race cars and we see the contrails form off aerodynamic devices but they dissipate quickly. No reason our planes would not have enough energy to trip a microclimate change when the conditions are right.

Tennessee
01-03-2019, 10:46 AM
There have been a lot of interesting responses, but I think the original poster was just trolling the Super Cub owners.:-P. Unless he really does have a rear view mirror in his Champ...

skywagon8a
01-03-2019, 11:22 AM
Another example. One clear cold winter day while flying a DC-9, I was held at FL180 because I was overtaking traffic at FL190. That traffic was leaving a very visible contrail. What do you suppose that traffic was? An obviously turbocharged Cessna Skymaster. Not a sight one would normally expect to see at altitude.

Eddie Foy
01-03-2019, 11:35 AM
"I was inverted!"

cubdriver2
01-03-2019, 01:09 PM
"I was inverted!"


When you became foggy?

Glenn

BC12D-4-85
01-03-2019, 02:09 PM
It's similar to creating ice fog in extreme cold...done it several times on skis. Ice or snow crystals stirred up or frozen exhaust turned the whole LZ into a fog bank. Typically after a snow event followed by clearing skies, no wind, and rapid heat loss at the surface via IR radiation. Happens here in Fairbanks from big rigs at -40F under right conditions.

Science: https://journals.ametsoc.org/doi/pdf/10.1175/AMSMONOGRAPHS-D-17-0002.1

Gary

JimParker256
01-03-2019, 06:20 PM
Had this happen to me at Fort Ord, CA (now-defunct Army base near Monterey) when I was flying OH-58 helicopters for the Army. We took off one evening when the dew point and temp were very close, but there was zero fog. As we climbed away, I noticed a "blurring" of the airfield lights behind us, and made a slight turn to get a better view. There was a wall of fog rolling across the ramp in all directions away from our takeoff point. I quickly called Base Ops (tower closed at night) and told them we were scrubbing the mission due to fog. The duty officer thought I was crazy, because looking out his windows, which faced the far side of the airport, it was severe clear. I told him to look out the door on the other side. Talking with him later, he said it was the weirdest thing he'd ever seen a solid wall of fog expanding outward like a mushroom cloud... Within minutes, the entire field was solid IFR, and the fog even spread 2-3 miles over to the adjacent town (Marina).

My hypothesis is that the air was perfect for forming fog, but there was no "nucleus" for the vapor to coalesce around until we began our takeoff and cleared the edge of the pavement, kicking up some dust. That provided the initial nucleus for the fog to form, and once it started forming, it just self-propagated. Like I said, one of the weirdest meteorological events I've ever witnessed.