the conditions this morning didn't allow for persistent contrails at normal high altitude so this one looked a bit out of place.
By the time I spotted the plane responsible it was no longer leaving a contrail, but it was still below 28,000 feet and climbing: it had only recently taken off from Stansted.
A couple of minutes later another plane out of Stansted passed on a similar track and was also leaving a contrail. When I took this FR24 screenshot it was at 26,640ft and the contrail stopped shortly afterwards. Based on the rate of climb the contrail must have started below 26,000ft. (The more distant plane at 35,000ft was visible glinting in the sun but not leaving even a short trail.)
Here are the same two trails a few minutes later.
Shortly afterwards they were joined by a third form a flight on a similar track.
The first plane was an A320, the second and third were B737s, not turboprops like other low-altitude trails that have been noted recently by @Trailspotter.
By the time I spotted the plane responsible it was no longer leaving a contrail, but it was still below 28,000 feet and climbing: it had only recently taken off from Stansted.
A couple of minutes later another plane out of Stansted passed on a similar track and was also leaving a contrail. When I took this FR24 screenshot it was at 26,640ft and the contrail stopped shortly afterwards. Based on the rate of climb the contrail must have started below 26,000ft. (The more distant plane at 35,000ft was visible glinting in the sun but not leaving even a short trail.)
Here are the same two trails a few minutes later.
Shortly afterwards they were joined by a third form a flight on a similar track.
The first plane was an A320, the second and third were B737s, not turboprops like other low-altitude trails that have been noted recently by @Trailspotter.