'Victory' means more passenger uncertainty – and threatens disruption at height of summer

Until six pm yesterday there was one group of airline passengers who enjoyed that rarest of aviation commodities: certainty. They were the British Airways passengers who knew that their flights had been cancelled by the impending cabin crew strike. Suddenly, BA won another injunction on a technicality in the ballot, and today 6.20 am to Manchester was back on the departure screen.

A victory for the airline? In the short term, undoubtedly. From the point of view of the members of Unite who are bankrolling the bitterest dispute in UK airline history, to lose two High Court cases on ballot irregularities may look like carelessness. But from the long suffering passengers' perspective the uncertainty has just got a whole lot worse. Cabin crew are likely to conduct, very carefully, a third ballot which in turn jeopardises the schedules for the peak months of July and August and if the BA strike does not get you the volcanic ash may well.

Sixty nautical miles translates as around 70 of the Imperial variety. In a compact and densely populated country such as Britain, that is a fair distance – quite enough, for example, to immobilise several airports if added to a forecaster's projection of the progress of a cloud of volcanic ash. Yet last week the 60 nautical mile "Buffer Zone" vanished overnight in a puff of ash from the aviation charts.

The Civil Aviation Authority (CAA) made the move because there was "no scientific basis" for what it called an "arbitrary" belt to exist in the first place. Yet the Buffer Zone was established a month ago when the skies re-opened after the six-day shutdown. At the time, we were assured that only sound scientific evidence would be used to define the No Fly Zone that determined whether or not your business trip, family visit or holiday would go ahead.

Aviation safety is built on strictly enforced limits. From crosswinds to visibility and pilots' hours to the g-forces each seat must withstand, clear boundaries are specified – with a margin for safety built in. The UK airline industry's obsession with safety means restrictions are meticulously observed, which is why a Thomson flight from Lanzarote to Gatwick was allowed to land four minutes before the 1am deadline yesterday, but the wave of flights scheduled to follow just a few minutes later were not.

And what's wrong with that? After all, the very same regulators who some criticise for excessive caution are those who have helped ensure that Britain's air safety record is the envy of the world. What's wrong, from the perspective of the passengers left stranded by the present crisis, is that we are not convinced by the CAA's belt, braces and Buffer Zone approach to the issue. That attitude is unlikely to raise a smile from the bright men and women who map out the imagined progress of the poisonous pockets of ash. They will solemnly respond that they are working to the criteria agreed with airlines and manufacturers of engines and airframes.

Everyone accepts that the exact science of pure mathematics is all very well until you start applying it to the real world, and in particular the restless earth and four winds. In such circumstances, risk management is the most inexact of sciences. But the buffer zone of passenger tolerance is eroding fast. It may well be that we must, as the CAA has warned, jolly well get used to it. But we need to be convinced that the rules that are causing so much economic and emotional grief are less arbitrary than the Buffer Zone.