Flight altitude over Leeds, UK

[Flies-like-a-chicken]

Hi,

I'm a third year Meteorology student at the University Of Leeds doing my dissertation on the persistence of aircraft contrails over Leeds. I'd really like to hear from a pilot who has flown over Leeds who could tell me roughly what altitude most air traffic cruises at in the area. I'm aware that this may breach some official secrets act or similar bureaucratic nonsense but a ball park figure would be very helpful! (metric or not)
Thanks,

[kenparry]

There's no short answer. Altitude depends on type of aircraft and phase of flight.

Jet airliners usually cruise at roughly 29000 to 37000 feet, and contrails are usually at that sort of altitude - though you should know from your studies that their existence, and persistence, vary with atmospheric conditions. The overflight traffic making trails will be in that sort of band.

Some business jets will go up to 50000 ft or so; prop aircraft will rarely be above 25000 ft, so don't often get into trails.

Have you met the "Tephigram" yet? It can tell you where (in altitude terms) contrails are likely, but it does not address persistence.

[Flies-like-a-chicken]

Thanks for your answer. I've been assuming a cruising altitude of 10.7 km (an estimate by the IPCC). Through the pprune I have since found out from a pilot living in the area that the north-south traffic in the area cruises at a lower altitude (approx 9 km). Tephigrams have been an integral part of my dissertation but analysing relative humidites with respect to ice when the reference height is uncertain has caused significant systematic errors. Thanks anyway for the help.

FLAC