It should have been the start of what BAA, Heathrow’s owner, had described as “a new era for air travel”, a demonstration to the world that when it comes to grand design and unruffled efficiency, Britain can still cut it. Terminal 5 would “streamline your journey through Heathrow”, giving passengers “the time and space to rediscover the joy of flying at one of the world’s great airports”. As for British Airways, given monopoly use of this jewel in Heathrow’s crown, it could not wait.

“We have done as much as we possibly can and we are ready,” boasted Willie Walsh, BA’s chief executive, a week ago. “I look at the terminal building and speak to the people involved and we are genuinely fit for 5.” Not since the White Star Line declared the Titanic unsinkable has there been such an example of hubris.

Nobody, apart from Britain’s rivals, can take pleasure in the chaos that marked terminal 5’s opening last week and which has continued into this weekend. An innovative and well designed building, which cost £4.3 billion, should have been a success from the start and, as it boasted, a new era for travellers more accustomed to squalor and congestion at Heathrow.

The failings at terminal 5 must not be allowed to become a symbol of modern British incompetence and a harbinger of the 2012 Olympics. Rather, they should be a lesson, were it needed, that between them BAA and BA - both former nationalised industries - are uniquely qualified at snatching defeat from the jaws of victory.

These things pass. London’s Millennium (formerly wobbly) Bridge, does not wobble any more. Terminal 5 will get over its teething troubles and will make life slightly more bearable for travellers using Heathrow. Although memories of the past few days will not easily fade and there will be plenty more Heathrow fiascos, usually involving BA, we should not write off terminal 5 yet.

What we should do, once more, is question the further expansion of Heathrow. Does BAA deserve to be entrusted with a sixth terminal and a third runway? No. The lesson of the terminal 5 chaos is that however much you spend trying to bring Heathrow into the 21st century, its fundamental problems will remain.

Heathrow is in the most congested part of the most congested region of Britain and contributes greatly to that congestion. Its location is both an anachronism and an environmental nightmare. Next time the Queen entertains Nicolas Sarkozy at Windsor Castle, the conversation will be drowned out by aircraft noise.

The government, it seems, has made up its mind that Heathrow’s further expansion should go ahead, whatever the objections. That should come as no surprise. Official documents released under the Freedom of Information Act that we report today show the extent to which the Department for Transport has colluded with BAA. We will keep up the pressure for expanding capacity east of the capital. After the recent chaos at Heathrow, the case is getting stronger.