Re: Contrails

[Steven P. McNicoll]

"Jeffrey Voight" > wrote in message
...
>
> I'm curious about something I frequently see. When I look up and see
> contrails from airplanes, I often see more than one headed in the same
> direction, but separated by some distance. I figure this is a result of
> the trailing aircraft not wanting to fly along in the contrail left by
> the lead aircraft and/or the wind pushing the contrail to the side prior
> to the trailing aircraft. What I don't get is why I see them bend at or
> about the same location. Is this the result of the wind changing
> direction at this location? Perhaps the pilots are flying VOR to VOR
> and that bend is where the local VOR is?
>

That is most likely.


>
> I would have thought that most
> flights at altitudes that produce contrails would be on GPS plans, so
> I've discounted this theory a bit.
>

In heavy traffic areas aircraft are still tied to preferential routes along
airways regardless how they're equipped.

[Jay Honeck]

> Perhaps the pilots are flying VOR to VOR
> and that bend is where the local VOR is?

Iowa City was on the original transcontinental air mail route. When they
switched from light beacons to radio beacons, Iowa City received a VOR.

(In the 1920s and 30s, Iowa City has a 500,000,000 candlepower beacon!
That's half a BILLION candlepower -- it was reported in the newspapers that
area farmers were able to work at night, by the light of the beacon!)

These routes evolved into the airways airlines (and many IFR pilots) still
use today.

On a clear day you can see dozens of airliners overhead, changing course at
the VOR just south of town. 99% of the population has no idea why.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Larry Fransson]

On 2003-12-06 12:32:51 -0800, Jeffrey Voight > said:

> I would have thought that most
> flights at altitudes that produce contrails would be on GPS plans....

Two things:

1. There are lots of big airplanes flying around that still have nothing more than
the good old VOR & DME.

2. GPS doesn't always mean direct.

--
Larry Fransson
Seattle, WA

[Cub Driver]

> What I don't get is why I see them bend at or
>about the same location

I suspect it's winds aloft.

all the best -- Dan Ford
email:

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

[Jim Weir]

No, no, Jay. You know damned good and well those are chemtrails dusting us with
evil powders.

Jim


"Jay Honeck" >
shared these priceless pearls of wisdom:

->On a clear day you can see dozens of airliners overhead, changing course at
->the VOR just south of town. 99% of the population has no idea why.

Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

[Steven P. McNicoll]

"Jay Honeck" > wrote in message
news:VJrAb.441007$HS4.3464811@attbi_s01...
>
> Iowa City was on the original transcontinental air mail route. When they
> switched from light beacons to radio beacons, Iowa City received a VOR.
>

Well, actually, they didn't. When radio navigation was introduced in the
late twenties it was in the form of the four course A-N radio range, VOR
didn't come along until the late forties.


>
> (In the 1920s and 30s, Iowa City has a 500,000,000 candlepower beacon!
> That's half a BILLION candlepower -- it was reported in the newspapers
that
> area farmers were able to work at night, by the light of the beacon!)
>
> These routes evolved into the airways airlines (and many IFR pilots) still
> use today.
>

I have a 1939 Des Moines sectional chart. It shows the airway passing just
south of the Iowa City Airport. The airway is defined by A-N ranges at
Moline and Des Moines. There's a rotating beacon on the field at Iowa City,
and rotating beacons with course lights on the airway southeast and
southwest of Iowa City.

The 1945 sectional shows the airway now designated Green 3 and an NDB at
Iowa City.

The 1948 sectional shows some extensions to controlled airspace around the
Iowa City airport, no doubt to contain an instrument approach. The only
change to the visual or radio navaids is the addition of a visual ground
sign about three miles northwest of Riverside.

The 1953 sectional shows significant changes. The airway light beacons,
visual ground sign, and the NDB are gone. The Iowa City VOR is located
where the visual ground sign was. V6 and V8 run from the Des Moines VOR
through Iowa City VOR to the Moline VOR. The Des Moines VOR is located
about three miles south-southwest of the Des Moines Range, the Moline VOR is
located about four miles northeast of Cordova, Illinois.

The 1960 sectional shows a few more airways defined by the IOW VOR.

The 1964 sectional no longer shows the A-N ranges.

[Ash Wyllie]

Jim Weir opined

>No, no, Jay. You know damned good and well those are chemtrails dusting us
>with evil powders.

Damn. I was just about to post the same explaination.

-ash
for assistance dial MYCROFTXXX

[Jeff Franks]

I live "almost" under a convergence of airways. Most any clear fall
evening, you can count the contrails into the double digits. And most all
of them bend in the same place....following an airway one way or the other.
By dark, you can generally make out where the airways are and aren't.

Jeff

"Jeffrey Voight" > wrote in message
...
> I'm curious about something I frequently see. When I look up and see
> contrails from airplanes, I often see more than one headed in the same
> direction, but separated by some distance. I figure this is a result of
> the trailing aircraft not wanting to fly along in the contrail left by
> the lead aircraft and/or the wind pushing the contrail to the side prior
> to the trailing aircraft. What I don't get is why I see them bend at or
> about the same location. Is this the result of the wind changing
> direction at this location? Perhaps the pilots are flying VOR to VOR
> and that bend is where the local VOR is? I would have thought that most
> flights at altitudes that produce contrails would be on GPS plans, so
> I've discounted this theory a bit. If it's the result of the wind
> changing, wouldn't the wind shear destroy the contrail at that bend?
>
> I don't get it.
>
> Jeff...

[H. Adam Stevens]

"99% of the population has no idea why."
Jay, I submit this is generally true.
;^)
H.

"Jay Honeck" > wrote in message
news:VJrAb.441007$HS4.3464811@attbi_s01...
> > Perhaps the pilots are flying VOR to VOR
> > and that bend is where the local VOR is?
>
> Iowa City was on the original transcontinental air mail route. When they
> switched from light beacons to radio beacons, Iowa City received a VOR.
>
> (In the 1920s and 30s, Iowa City has a 500,000,000 candlepower beacon!
> That's half a BILLION candlepower -- it was reported in the newspapers
that
> area farmers were able to work at night, by the light of the beacon!)
>
> These routes evolved into the airways airlines (and many IFR pilots) still
> use today.
>
> On a clear day you can see dozens of airliners overhead, changing course
at
> the VOR just south of town. 99% of the population has no idea why.
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"
>
>

[G.R. Patterson III]

"Steven P. McNicoll" wrote:
>
> I have a 1939 Des Moines sectional chart........

Do you collect old sectionals, or is there a library of these things someplace?

George Patterson
Some people think they hear a call to the priesthood when what they really
hear is a tiny voice whispering "It's indoor work with no heavy lifting".

[Thomas Borchert]

H.,

> "99% of the population has no idea why."
> Jay, I submit this is generally true.
>

But they have strong beliefs - Oh NO, wrong thread... <gd&r>

--
Thomas Borchert (EDDH)

[H. Adam Stevens]

ROTFLMAO
thanks
H.
"Thomas Borchert" > wrote in message
...
> H.,
>
> > "99% of the population has no idea why."
> > Jay, I submit this is generally true.
> >
>
> But they have strong beliefs - Oh NO, wrong thread... <gd&r>
>
> --
> Thomas Borchert (EDDH)
>

[Steven P. McNicoll]

"G.R. Patterson III" > wrote in message
...
>
> Do you collect old sectionals, or is there a library of these things
someplace?
>

I collect old sectionals.

[Jay Honeck]

Fascinating stuff, Steven -- thanks!

Would it be possible to con you into scanning those sectionals for me?
(Just the area around Iowa City, of course -- not the whole thing!)

I'd like to include them in my ever-evolving "History of the Iowa City
Airport" (which you are at in no small measure responsible for me starting,
BTW!) page. It would really help fill some BIG gaps in our knowledge.

You can see version 3.0 of this effort at
http://www.alexisparkinn.com/the_iowa_city_airport.htm
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"Steven P. McNicoll" > wrote in message
ink.net...
>
> "Jay Honeck" > wrote in message
> news:VJrAb.441007$HS4.3464811@attbi_s01...
> >
> > Iowa City was on the original transcontinental air mail route. When
they
> > switched from light beacons to radio beacons, Iowa City received a VOR.
> >
>
> Well, actually, they didn't. When radio navigation was introduced in the
> late twenties it was in the form of the four course A-N radio range, VOR
> didn't come along until the late forties.
>
>
> >
> > (In the 1920s and 30s, Iowa City has a 500,000,000 candlepower beacon!
> > That's half a BILLION candlepower -- it was reported in the newspapers
> that
> > area farmers were able to work at night, by the light of the beacon!)
> >
> > These routes evolved into the airways airlines (and many IFR pilots)
still
> > use today.
> >
>
> I have a 1939 Des Moines sectional chart. It shows the airway passing
just
> south of the Iowa City Airport. The airway is defined by A-N ranges at
> Moline and Des Moines. There's a rotating beacon on the field at Iowa
City,
> and rotating beacons with course lights on the airway southeast and
> southwest of Iowa City.
>
> The 1945 sectional shows the airway now designated Green 3 and an NDB at
> Iowa City.
>
> The 1948 sectional shows some extensions to controlled airspace around the
> Iowa City airport, no doubt to contain an instrument approach. The only
> change to the visual or radio navaids is the addition of a visual ground
> sign about three miles northwest of Riverside.
>
> The 1953 sectional shows significant changes. The airway light beacons,
> visual ground sign, and the NDB are gone. The Iowa City VOR is located
> where the visual ground sign was. V6 and V8 run from the Des Moines VOR
> through Iowa City VOR to the Moline VOR. The Des Moines VOR is located
> about three miles south-southwest of the Des Moines Range, the Moline VOR
is
> located about four miles northeast of Cordova, Illinois.
>
> The 1960 sectional shows a few more airways defined by the IOW VOR.
>
> The 1964 sectional no longer shows the A-N ranges.
>
>

[Steven P. McNicoll]

"Jay Honeck" > wrote in message
news:UzpBb.289730$Dw6.973889@attbi_s02...
>
> Would it be possible to con you into scanning those sectionals for me?
> (Just the area around Iowa City, of course -- not the whole thing!)
>

Okay. They're big files so I'm sending them to you individually. If you
have a problem with them I'll post them to alt.binaries.pictures.aviation

[Steven P. McNicoll]

"Steven P. McNicoll" > wrote in message
nk.net...
>
> Okay. They're big files so I'm sending them to you individually. If you
> have a problem with them I'll post them to alt.binaries.pictures.aviation
>

I made the files large for good detail. They were apparently too large, as
they bounced back as undeliverable. I have posted them to the
alt.binaries.pictures.aviation group, the subject lines begin "Iowa City
area..."

[Greg Burkhart]

There only shows one part of the picture there, part 3 of 3. Possibly a
problem with my news server... :-(

"Steven P. McNicoll" > wrote in message
ink.net...
>
> "Steven P. McNicoll" > wrote in message
> nk.net...
> >
> > Okay. They're big files so I'm sending them to you individually. If
you
> > have a problem with them I'll post them to
alt.binaries.pictures.aviation
> >
>
> I made the files large for good detail. They were apparently too large,
as
> they bounced back as undeliverable. I have posted them to the
> alt.binaries.pictures.aviation group, the subject lines begin "Iowa City
> area..."
>
>

[Steven P. McNicoll]

"Greg Burkhart" > wrote in message
news:6EMBb.302325$Dw6.1006383@attbi_s02...
>
> There only shows one part of the picture there, part 3 of 3. Possibly a
> problem with my news server... :-(
>

I use Earthlink, all three showed up on mine just fine.