No airline or member of the public can take legal action against National Air Traffic Services (Nats) for the organised chaos caused by computer problems last weekend.
As a public body, Nats has a statutory immunity from legal action. So the passengers who arrived at Gatwick airport from a long-haul flight and then found themselves kept on the plane for a further six hours because of the knock-on effect of the computer problems, will have to accept their lot. As will thousands of other travellers whose flights were delayed by five or more hours.
The system went down for only about three hours on Saturday morning. But so many flights were cancelled or delayed, crew schedules disrupted, and planes left in the wrong place when "normal" service was resumed, that the ripple effects lasted for days.
Since Nats is not accountable to the general public or to any shareholders, the organisation is not compelled to offer a full explanation of what went wrong or what measures are being put in place to avoid a repetition.
Yet this is necessary not only as a means of showing the public, Parliament and MPs that it regards itself as accountable. It is also necessary for good project management.
In an independent report that studied the management style and culture at Nats last year, consultancy Arthur D Little pointed out that the organisation had become more open. But it was not open enough.
"Nats should take further proactive measures to achieve a more open management culture," said the report. "Irrespective of formal project procedures, achieving a management culture where there is openness and receptivity to challenges on key assumptions is critical."
Yet today Nats tends instinctively to field, rather than fully answer, awkward questions about its systems. And staff who leave Nats tell us that the organisation is still less than receptive to criticism: those who do criticise any part of the system design or implementation are regarded by the service as disaffected or ignorant.
The cry in the press is that when Nats is privatised this will instill a more professional and commercial approach to systems management.
But in IT terms there has been a private public partnership for eight years. It has left Nats with a £677m new air traffic control centre at Swanwick, Hampshire, that was completed in the early 1990s but has yet to go operational, partly because of problems with the externally-supplied hardware and software.
In any case, Nats already has some of the best IT staff and skills in the industry. For 99.9% of the time it runs an exemplary service. If there is a deep-rooted problem, it is with the organisation's culture.
This culture dictates that people do not talk about bugs or software problems. They refer to them as Programme Trouble Reports. And there is no such thing as a big problem. Any difficulty that could affect lower-level requirements, more than one software module, or more than 500 lines of code, is called an Issue Analysis Document.
If a public organisation cannot own up to the seriousness of its problems, can it be expected to solve them?