I can't ID this flight of Oct 5th [Alaska 577]

[steve holmes]

On the evening of Oct 5th, I saw a very persistent trail heading NW from where I was in McKinley Park, Sacramento, at 6:24 pm. Here's a few pictures of the trail and also what results I got when trying to ID it on flightradar24.com.
There were several "persistent" trails that I saw between 6:00 and 7:00 pm, which was followed the next 2 days by lots of more persistent trails while during most of the day (Oct 5th) the trails were short (and as you can see by this being number 37 for me that day, there were plenty of them to see)

 

[Trailblazer]

I am heading out shortly so I can't look at his in detail but I will point out that this trail is a very long way away from your location, based on how low it appears in the sky. Mick has a handy graphic showing how the height above the horizon can be used to get a rough idea of the horizontal distance to the plane.

Obviously to get an accurate distance you need to measure the angle above the horizon accurately, but at a rough guess I would say 30 miles plus in this case. You might need to extend your search.

Without knowing the camera location and direction you are facing it's hard to be more specific.



http://contrailscience.com/how-far-away-is-that-contrail/

 

[Trailspotter]

This is easy, because I can pinpoint your location on Google Earth / StreetView. The flight is Alaska Airlines 577.

I have downloaded the kml file of its track from FlightAware (attached) and looked at it in Google Earth from the nearest Google car stop:

The track is slightly higher relative the tree line than in your photos, but this could be because either you were closer to the trees, or the contrail was carried further East by the wind in a few minutes since the plane passed, or both.

 

[Jay Reynolds]

On the evening of Oct 5th, I saw a very persistent trail heading NW from where I was in McKinley Park, Sacramento, at 6:24 pm. Here's a few pictures of the trail and also what results I got when trying to ID it on flightradar24.com.

Steve it sounds like you are trying to identify all trails you see in the sky. That should rapidly develop you into a highly skilled person but will also leave you with plenty which will remain unidentified for various reasons.

Along the way, I suggest you find at least one identifiable flight which suits the timeframe when you are most available to make a daily observation. Look for it, anticipate it, observe and document the same flight over time for a few weeks on a daily basis. Find a way to assemble your results for easy presentation to others and then publish it.
A video format like this is an idea.
https://www.youtube.com/user/LasVegasSkyWatch

You and others stand to learn a lot from that exercise if you tried.

 

[Mick West]

I also took some photos of Alaska 577, from Shingle Springs

I even took a video as it approached from the south, and several photos.

 

[steve holmes]

I am heading out shortly so I can't look at his in detail but I will point out that this trail is a very long way away from your location, based on how low it appears in the sky. Mick has a handy graphic showing how the height above the horizon can be used to get a rough idea of the horizontal distance to the plane.

Obviously to get an accurate distance you need to measure the angle above the horizon accurately, but at a rough guess I would say 30 miles plus in this case. You might need to extend your search.

Without knowing the camera location and direction you are facing it's hard to be more specific.

View attachment 21907

http://contrailscience.com/how-far-away-is-that-contrail/

thanks. Good info.
When I go to Lake Tahoe and am at the southern end of it, trails on the northern end aren't really visible. Since it's 72 miles around the lake and it's fairly circular, without bothering to use a scale map to measure the distance across, it's probably 20-25 miles. It will be interesting to see what sort of angles I see on photos I've taken and see how they match up with the angles in this "guide".

 

[Mick West]

thanks. Good info.
When I go to Lake Tahoe and am at the southern end of it, trails on the northern end aren't really visible. Since it's 72 miles around the lake and it's fairly circular, without bothering to use a scale map to measure the distance across, it's probably 20-25 miles. It will be interesting to see what sort of angles I see on photos I've taken and see how they match up with the angles in this "guide".

It's 20 miles North to South. But that's WELL within the visibility range of contrails. As an extreme example, from my house in Shingle Springs I've seen contrails just off the pacific coast, 115 miles away.

There is a discussion here:
https://www.metabunk.org/whats-the-farthest-distance-a-contrail-is-visible-at.t5628/

Try taking some photos with a theodolite app. Anything below about 20° is probably over 20 miles away.