Author Topic: (NGC) - Contrails (Read 4592 times)

Gliderjohn · « **on:** August 26, 2019, 09:23:56 PM »

Scenes from living in flyover country. All taken from my house.

12 sided dice

GliderJohn

Guzzistajohn · « **Reply #1 on:** August 26, 2019, 09:33:14 PM »

The moon shot is a beaut!

Numbercruncher · « **Reply #2 on:** August 26, 2019, 10:31:42 PM »

Not trying to hijack but I got this one about fifteen years ago at the McChord Air Base shows.

NC

pebra · « **Reply #3 on:** August 27, 2019, 12:52:19 PM »

"I was driving across the burning desert
When I spotted six jet planes
Leaving six white vapor trails across the bleak terrain
It was the hexagram of the heavens
It was the strings of my guitar
Amelia - it was just a false alarm"

John Ulrich · « **Reply #4 on:** August 27, 2019, 04:08:38 PM »

My buddy who was in the jet engine end of the military is all over this contrail stuff. To sit with him for an hour with his "insider track" you'd be a believer too!

kirby1923 · « **Reply #5 on:** August 27, 2019, 04:22:26 PM »

Total nonsense, contrails are just the product of combustion as in water vapor. When there is a lot of moisture aloft you get con trails. End of story.

High bypass engines put out just as much heat (or more ) than low bypass engines and make great contrails.

Good grief.....

The internet strikes again.......

kirby1923 · « **Reply #6 on:** August 27, 2019, 04:46:48 PM »

Amen!

50 years of making con trails.......

StuCorpe · « **Reply #7 on:** August 28, 2019, 03:30:00 PM »

Here's one I took back in 1980 while going through Valley of the Gods on my way from Kingman, AZ.

Gliderjohn · « **Reply #8 on:** August 28, 2019, 03:52:34 PM »

I have not seen any gliders display contrails. May be somewhat due to most glider aerobatics are much less violent or less abrupt for the most part compared to powered planes although can still pull a lot o G. Coming in September is going to be the national aerobatic glider championships in Salina, KS. Planning to check out at least one day. Maybe see it happen there.
GliderJohn

cloudbase · « **Reply #9 on:** August 28, 2019, 04:31:39 PM »

Vey iz mir!

The spiraling is perfectly normal and is caused by wingtip vorticies.

When ATC tells you "caution, wake turbulence" you'd better pay attention.

Tom H · « **Reply #10 on:** August 28, 2019, 04:44:47 PM »

Under the right conditions, drag race cars and occasionally a F1 car will get a trail off their wing tips.

Tom

hzbloke · « **Reply #11 on:** August 28, 2019, 05:05:17 PM »

Under the flightpath from Melbourne to Sydney (the second busiest domestic route on earth). One of the airports was closed due to fog.

Gliderjohn · « **Reply #12 on:** August 28, 2019, 05:23:25 PM »

From the Paul Bowen collection.

GliderJohn

Neil · « **Reply #13 on:** August 28, 2019, 05:25:24 PM »

Two items:
I have a photo buried in the archives of a military jet showing a very similar thing to the photo Numbercruncher posted, taken at the Pratt & Whitney air show back in the 1990-91 time frame .
Also in the archives is a photo my dad took out the waist gunner's window of a B17 during WWII , showing the contrails being formed by the propeller tips. So, the contrail is not always from the exhaust.

dguzzi · « **Reply #14 on:** August 28, 2019, 05:34:29 PM »

I've been sending my secret mind control recipe to them for years. Thats why bacon tastes so good. hehehe no longer a secret!

Get it, pork bellies have been velly velly goot aa to me.

pete roper · « **Reply #15 on:** August 28, 2019, 06:50:56 PM »

They turn you Welsh Chuck.

oldbike54 · « **Reply #16 on:** August 28, 2019, 07:47:39 PM »

<SIGH> Please keep your conspiracy theories about what a government is doing off of Wild Guzzi . Thanks

Dusty

Moz · « **Reply #17 on:** August 28, 2019, 07:55:32 PM »

Quote from: oldbike54 on August 28, 2019, 07:47:39 PM

<SIGH> Please keep your conspiracy theories about what a government is doing off of Wild Guzzi . Thanks

Dusty

Poe's law is an adage of Internet culture stating that, without a clear indicator of the author's intent, it is impossible to create a parody of extreme views so obviously exaggerated that it cannot be mistaken by some readers for a sincere expression of the views being parodied.

The original statement, by Nathan Poe, read:

Without a winking smiley or other blatant display of humor, it is utterly impossible to parody a Creationist in such a way that someone won't mistake for the genuine article.

Gusable · « **Reply #18 on:** August 28, 2019, 09:09:15 PM »

My wife claims to have seen project aurora fly over our house years ago. It leaves bumps on a rope contrails. This was at night and was a black triangle haulin the mail headed to Cali!!!

Two Checks · « **Reply #19 on:** August 29, 2019, 11:10:45 AM »

Quote from: Daniel Kalal on August 28, 2019, 03:25:04 PM

the creation--and therefore avoidance--of contrails was studied extensively during ww2 to modify the cruising altitudes for the daylight bombing raids (for obvious reasons). Of course, the B17 is powered by four seriously high-bypass engines...

Frankly, this is the first I've ever heard of any dark conspiracy attached to contrails. Really? How strange. I'd think that under the right conditions even an unpowered sailplane could make contrails from the wing tips (not including water-dumping of course)--pressure/temperature/humidity. GliderJohn, have you seen any photos of this phenomena?

Recip piston engines are NOT bypass engines. 100% of the air taken in goes through the cylinders.

And they used water/alcohol injection so there is your vapor trail. But even when an entire swarm of planes flew over the trails didn't grow until they became an overcast.

Nor do the wingtip vapor trails. And race cars produce vapor trails off their spoilers...why are there no trails coming from the exhaust?

Staying away from gummint. Talking strictly about the trails.

fossil · « **Reply #20 on:** August 29, 2019, 12:42:02 PM »

But those conspiracion theories are widespread. We were landing last month with an Airbus A 320 in Hamburg, it was cold and very moist. The control surfaces and especially the flaps had really nice contrails at their edges. In the row behind me three lovely young ladies began to discuss exactly these theories. Well, I had to burst their bubble....

The finest example of contrails I have seen on a photograph made by a friend with a high-powered Canon - camera from another friend who was just starting with his Yak 50. The propeller laid a perfect double helix around the whole plane. It was cold and moist...

Penderic · « **Reply #21 on:** August 29, 2019, 01:11:43 PM »

Contrails remind me of the good old days.

John A · « **Reply #22 on:** August 29, 2019, 01:35:47 PM »

Somebody should mention aerodynamic compression somewhere in here. I would but im in the waiting room at the clinic where ive brought Mom. I think it shingles

Two Checks · « **Reply #23 on:** August 29, 2019, 03:19:24 PM »

Ahem....we were talking about trails created by engine exhaust. BUT now that you say a recip piston engine is a high bypass engine you prove my point. The propellers don't make trails in the sky that grow into a complete overcast.
As stated in another post those trails made by the wingtip of the A320 went away, right? They didn't remain and grow.

kirby1923 · « **Reply #24 on:** August 29, 2019, 09:45:25 PM »

All the con trails you can see from the ground of high flying aircraft are from engine exhaust. The B-17 is from the turbos and in a jet its from the turbine. P-51 is from raw exhaust.

They only appear if there is allot of moisture aloft near 5 miles up.

When its dry aloft you will not see contrails.

Prop and wing tip con is invisible at high altitude from the ground.

This "chem trail" nonsense is just that nonsenses.

Gliderjohn · « **Reply #25 on:** August 29, 2019, 10:03:32 PM »

Didn't expect all the controversy, was just trying to post what I thought were kind of cool pictures of aircraft in my hood. No offenses I hope.
GliderJohn

kirby1923 · « **Reply #26 on:** August 30, 2019, 01:37:20 AM »

Hey John,

I don't call it "controversy" and I'm thinking it was a good topic as there is allot of mystery about a simple display of physics. I can't tell you how many folks have talked to me about con trails when they find out I have lived w/them for many years.

Magnificent display of power.

:-)

sidmonsters · « **Reply #27 on:** August 30, 2019, 10:50:39 AM »

John--just rejoined this thread to see that my snarky comments about my brother-in-law's fixation with "chemtrails" was evidently the spark (and was removed). Apologies. I think the pictures and scientific discussion are awesome...the daft conspiracy theories not so much.
Steve

Murray · « **Reply #28 on:** August 30, 2019, 11:06:26 AM »

Quote from: gliderjohn on August 28, 2019, 03:52:34 PM

I have not seen any gliders display contrails.

Once upon a time there was a multi quote function either I can't find it or its not there anymore, nm. Part of the reson gliders been what they are are extermely aerodynamically efficent the only contrails they have a chance of making would be wing tip vortecies which is a form of drag. I'm pretty sure you can rattle of tbe best L/D speed of what you regulary fly as well as what speed the polar curve goes to crap, all aerodynamic properties for those playing at home.

Another post metioned something about been cold and moist when some prop vortecies were captured, cold and moist genrally makes for poor thermal forming conditions.

Bill · « **Reply #29 on:** August 31, 2019, 03:52:03 PM »

I thought contrails were easy to explain. I learned they are caused by condensation nuclei. The exhaust of the engines spew particles in to the atmosphere. Water molecules form around them then we have a contrail. Maybe I was misinformed.
Bill
I've created lot's of contrails, but I never saw them from the cockpit. LOL!

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Author Topic: (NGC) - Contrails (Read 4592 times)

pete roper

oldbike54