Simon Calder's Holiday Helpdesk: Does it happen often that a transatlantic superdeal vanishes in the night?

Q. I have a daughter living in Canada and a son moving to San Francisco. I did all the usual price checks using many airlines. Then I happened on Lufthansa (member of Star Alliance) and decided to give it a try. Put in the details out Heathrow-Edmonton, Edmonton-San Francisco, San Francisco-Heathrow.

To my amazement up came non-stop flights for each of those sectors for an incredible £727. I assumed that the site had given me those flights as all the companies were members of the Star Alliance. Anyway, once i got the OK from my son on Monday I went back to Lufthansa site. Now no direct flights on any days in any month, all flights via Germany. Price £1,026. Obviously, someone corrected the website. What a pity. I thought that it was too good to be true! Does this happen often?

Alan Lea, Warwickshire

A. How frustrating. I've sometimes found prices that look wonderfully cheap, and learned that you have to snap them up or watch them vanish in days or even hours; I've recently paid a couple of hundred pounds extra for a transatlantic trip because I wanted to consider the deal overnight.

Your experience is a worthwhile reminder that alliance partners sell each others' flights as though they were their own. I've found occasions when booking BA/Flybe combos are different prices depending whose website you go through, and international discrepancies are even more widespread.

While the principle is that the fares should always be the same on any airline's platform, there can sometimes be wrinkles that create excellent opportunities - which must be seized, or missed. If it makes you feel any better, though, sometimes when especially low fares are shown they turn out to be unbookable by the time you get to the payment stage.

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