It not mentioned from which UK airport(s).
Those times may be good from, let's say, LGW, LTN or STN but the likes of BRS, CWL & MAN are longer, Scotland even moreso and, back in the day, BFS/LCA/BFS would be a particularly long day with the occasional B737-300 fuel stop in to LPL on the return leg.
As for scheduling the biggest problem is crew duty hours, unless from the south-east airports mentioned I recall scheduling was circa 4.66 hours going out and 5.25 hours coming back, 9.9 hours plus a 1 hour crew report plus a 1 hour turnround equals a flight duty period of 11.9 hours, at the best time of day (morning) crew could do 13.25 hours, come an afternoon report 12.25 hours which doesn't leave much leeway in the event of a delay, a bad slot or whatever, and come an early evening report then the crew could only do something like 11 hours ... Unless the operator have slip crews in Cyprus (as my then operator sometimes did) or wherever.
Last edited by Harry Wayfarers; 14th June 2017 at 01:19.