THE air was pierced with ear-splitting roars, banshee wails and thunderous explosions. And that was just Boeing and Airbus insulting each other. With all its noisy fighters, sleek missiles and other boyish toys, the biennial Paris Air Show usually lets more testosterone into the atmosphere than is conducive to civilised commercial competition. But this year the international aerospace industry has another casus belli. Politics, which has long governed the defence part of its business, has now determinedly entered the civil side as well.

The first to fly off the handle was the boss of Airbus Industrie, Jean Pierson. He accused McDonnell Douglas of deliberately losing the contract to develop a prototype of America's Joint Strike Fighter (JSF), in order to make it easier to merge with Boeing, which reached the final round alongside Lockheed Martin. This is preposterous: losing the contract was the coup de grâce for McDonnell as an independent group, but the blow was not self-inflicted. Ron Woodard, president of Boeing Commercial Aircraft Group, dismissed the claims as “total lunacy”, adding that Boeing “was not into conspiracy theories”.

Mr Pierson also wants the European Commission to take action against Continental, Delta and American Airlines, which have all signed exclusive deals to buy only Boeing jets over the next 20 years. He points out—as does Karel Van Miert, the EU's competition commissioner—that such tie-ups are illegal in Europe. Mr Woodard counters that such deals take place only when an airline replaces all its fleet; there are no more such prospects around.

Airbus's ability to shoot back at Boeing has been limited by the fact that it has hardly presented a united front. The four members of its consortium—France's Aérospatiale, Germany's DASA, British Aerospace (BAe) and Spain's CASA—have been battling over the conversion of Airbus into a “single corporate entity” that would own the factories where Airbuses are made and assembled. Such a radical change would rip away more than half of Aérospatiale's business, so the French group has repeatedly tried to stall the transfer of its assets to Airbus.

On the eve of the show Aérospatiale's boss, Yves Michot, claimed his partners had come to a deal on his terms: Airbus would convert from a consortium into a company, but the factories would remain under the ownership of the partners. His partners promptly denied that any such agreement existed, though they made soothing noises about the need to be patient with the French company: its plans to merge with the fighter-maker, Dassault, on its way to privatisation have run into trouble with Lionel Jospin's new Socialist government. Mr Jospin was due to spell out his policy on the privatisation of state-owned defence and aerospace companies in a closing speech at Le Bourget on June 21st.

Meanwhile Mr Michot seems to be getting his way: the half-baked compromise on Airbus is that, to begin with, the Airbus company will manage the whole production process but not own the aircraft factories or employ the workers in them. But Manfred Bischoff, the diplomatic boss of DASA, and Sir Richard Evans, the blunt chief executive of BAe, are both determined that eventually the Airbus company should own the assets.

As Airbus prepares to launch plans for a giant double-decker super-jumbo next year, pressure on the French to make it a proper manufacturing company is growing. Unless Airbus makes irreversible progress towards an integrated commercial structure, neither the British nor the German government will advance any cheap loans to get the $10 billion project under way. Nor would Lockheed Martin, Boeing's great rival, want to enter the project as a risk-bearing partner. It is talking to Airbus about both the super-jumbo and collaboration on a new military transport plane.

The super-jumbo is not the only reason why BAe and DASA are keen to press ahead with the conversion of Airbus into a true company. They see that as a step towards the creation of a single European aerospace group, covering both civilian and military aircraft, and capable of working in partnership with American companies such as Lockheed Martin.

The geopolitics of the aerospace industry probably explains BAe's decision to join the Lockheed Martin team in the American competition for the JSF, rather than that of Boeing. BAe had the right to choose one or the other because Britain plans to buy 60 JSFs for its aircraft carriers. Although Sir Richard said the decision was made on technical grounds, the rivalry between Airbus and Boeing might have made BAe's presence in the latter's team uncomfortable. Sir Richard and Norman Augustine, Lockheed's chairman—whose companies are already working together on a new armoured scout vehicle—said their JSF collaboration could extend to other projects.

Nevertheless, BAe's chief aim remains to press ahead with restructuring in Europe. BAe and DASA, already working closely with each other on the Eurofighter, have talked about an equity link-up. Such a deal would remind the French that their partners' patience is not unlimited.