Unlike U.S. congressional committees, inquiring members of Britain's Parliament are deferential to civil servants, rarely object to waffled answers and never come armed with a corps of professional staff aides. Committees here observe the quintessential British rule - "Don't make a fuss."

Despite these handicaps, the Public Accounts Committee here has just uncovered enough about Concorde to insure that output of the costly supersonic airliner will cease next summer.

The bipartisan committee makes it plain that this is not because nasty New Yorkers won't let the plane land or because the bird guzzles too much high-priced oil. The answer, in simple form, is that successive Conservative and Labor governments have given the plane's maker, British Aircraft Corp., every inducement to pile on costs. It is thought unlikely that the French partners in the venture behaved much differently, since their cost also hit the stratosphere.

The result is familiar to students of the G-5A, the F-11 and other landmarks in Pentagon procurement: The cost of the Concorde reached levels that only an indulgent military could afford.

Unhappily for Concorde, it is a civilian plane, designed for civilian airlines. Even at comparative giveaway prices, they won't touch it.

The parliamentary committee, under Edward Du Cann, a former Tory party chairman, never did pin down Bruce MacTavish of the Department of Industry on the precise cost of making each Concord today. At one point in the hearings, MacTavish offered a figure of $75 million. At another he voluntered 51 million pounds, which is not the same thing at all but $14 million more.

This looseness would not work in Capitol Hill; at the Palace of Westminster, it is considered rude to press on.

MacTavish was allowed to be equally evasive about how much the manufacturer was trying to get for its planes, but at one point he did acknowledge that the state-owned British Airways had paid only the equivalent of $37 million each of its five copies.

In other words, the softest possible customer, one that had little choice but to buy, was paying less than half the actual cost of producing each plane. Only four other Concordes have been sold - naturally enough, to Air France, the state-owned French line.

At those cut-rate prices, was British Airways making money at least on the run to Washington? This time Anthony Rawlinson, who has been made a Companion of the Bath for his services to the Industry Department, replied.

"The operating results," he said, "I think are profitable, but if the aircraft . . . were limited to that route alone, it would not, I think, be profitable."

Having left that one hanging, Chairman Du Cann asked whether the government's failure to check on manufacturing costs had been responsible for their astonishing rise. The government, it turned out, had failed to conduct its customary routine audit of its contractor's costs until 1975.

"We have seen not evidence of it," MacTavish replied blandly.

But Du Cann had learned enough - perhaps in private - to tell a radio autience last night that Concorde is dying because of a "lack of control over production costs - the controls were careless." Since Du Cann was among the Tory leaders in the days when the decision to push on with Concorde was made, he can hardly be described as an unfriendly critic.

The government has limited the British taxpayers' production losses on Concorde to 200 million pounds, about $350 million. When plane No. 16 rolls off the line next summer, this ceiling is likely to be pierced. Even if it is not, plane No. 17 must, says the government, be sold at a price that will cover its cost.

So the committee concluded, "There appears to be no practicable possibility of production beyond 16 aircraft being authorized."

The French however, are still pretending otherwise, insisting that output will go on. But their taxpayers never see the bills, since most French levies are raised not by income tax but through hidden, regressive sales taxes on consumers.

Britain's $350 million production loss will go even higher unless - and this is unlikely - some buyer can be found for the last five operating planes. (The first two were prototypes and British Airways and Air France share nine.)

Moreover, this figure does not count the $1 billion already written off in developing Concorde.

Finally, Britain's share of the red ink is only half the deficit: The rest of the tab is picked up in Paris. Since the operating losse of both state air lines are not published, a definitive figure for the venture's total loss is not possible. But $3.5 billion is almost surely a conservative estimate.

Despite the comparative clarity of the Accounts Committee report, there is still a lingering suspicion here and in Paris that American jealousy of European technology, American insistence on a near-monoply of civilian aircraft have destroyed it.

Even Du Cann, after citing uncontrolled production costs, could not help feeding this sentiment in his broadcast interview. He said, "The Americans have been damned awkward. They are bitter commercial competitors. They want to knock Concorde on the head."

Today, the local union officials at British Aircraft Coporation charged that Americans had used "all means possible to delay Concorde in order to get time to catch up and produce their own supersonic airliner in the future."

This view is taken as gospel in Paris.