reply to post by Sly1one
Anyway I thought I would post this pic for those who like to have "evidence" of "chemtrailing" as this is about as good of evidence as one
would probably get if there was any...
Well, as you've learned from post just above, no this is not yet "evidence" of "chemtrailing".
Classic holding pattern.....and, through the frame of the photo, another jet passed over the same area, different altitude no doubt, and made a
persistent and "straighter" contrail. That one, though, shows signs of being more affected by wind shear and convection currents than the typical
holding pattern, which looks to have been made in more stable air.
(Just 1,000 feet altitude change can make a difference. We all may have noticed this when flying commercially. It's possible to avoid the
uncomfortable turbulence encountered in flight by changing altitude. The turbulence that spill the drink on your tray table will affect contrails
Holds like that at the higher altitudes where contrails will form are not as common as holding in the terminal area, in the arrivals phase for landing
at destination, and at lower altitudes. However, the times when it occurs up high is almost always due to Air Traffic Control reasons. The
controllers have several methods to sequence air traffic, if it gets too busy for them for any part of the day......this is one way, radar vectors
well off course and changing speeds are others. Depends on how busy it's getting, to what extreme they will go.
Finally, as I found this the other day for example (don't know where you were this morning). Here is the history of United "9831" on the 26th
December......from LAX to LAX. (Los Angeles, California). It was a maintenance test flight of a Boeing 757. You can see the ground track it flew,
so it could well have have made "odd" contrails, if conditions had been suitable, since it went up as high as 41,000 feet:
Oh, and here I see another flight "9831" is due to fly today (as I write this) out of SNA (Santa Ana, California):
(This time, a B-737, and only planning up to 13,000 feet, so no contrails for that one today. Does show the fact of test flights that occur, and the
"odd" flight number is United's internal method to identify test flights, and other special flights, from regularly scheduled passenger flights).