It was the final and bitter culmination of a series of battles Mr Allen had fought to establish the PAA against a backdrop of delay and mistrust.

His reign at the authority had been punctuated by poor public relations and a series of attacks by consultants and contractors as he battled to keep one of the world's biggest building projects within a tight budget.

But his final departure owed more to his attempts to keep the authority independent of its Government masters. Ironically, it is the reason they now cite for refusing to divulge any details of why Mr Allen had to go.

Insiders told the Sunday Morning Post the prime movers behind the sacking of Mr Allen were not the businessmen most vocal in their attacks on the PAA boss, but two senior Government officials - Secretary for Economic Services Mrs Anson Chan Fang On-sang and Financial Secretary Mr Hamish Macleod.

As they took their seats around the boardroom table at an undisclosed location, PAA chairman Mr Macleod raised the matter at hand: Mr Allen's removal. The man himself was absent.

Once the board had agreed in principle to Mr Allen's removal - and were notified officially that Dr Hank Townsend had accepted the job - the Government secretaries were able to move right on to his replacement.

Dr Townsend - who had accepted on the spot when he was secretly offered the top job on Wednesday - was a veteran of Bechtel Corporation, one of the world's largest and most influential engineering and construction companies. He had stepped down as consultancy project manager at the New Airport Projects Co-ordination Office (NAPCO) two weeks before.

Although he is tight-lipped about the background to his sudden elevation, it is clear Dr Townsend will have to summon all his experience to bring together an airport project critics say is beginning to veer dangerously off the runway.

Dr Townsend yesterday kept referring to the decisions that would be made by the PAA board. ''I assure you the basic principle is team-based leadership with very open communications between the various groups.'' He described himself as an employee of the PAA, seconded from Bechtel, and answerable to the board.

The curt press statement that announced the move included the curious but key phrase that Dr Townsend's work would ''involve close co-operation with the Hongkong Government, with contractors and with others involved in the project''.

An insider said the phrase said it all. That, and Dr Townsend's insistence on being answerable to his bosses, illuminated what had been the key to Mr Allen's removal: his stubborn refusal to acquiesce to the wishes of the PAA board, sparking the concern among Government officials which ultimately cost him his job.

Mr Allen was axed because he had assumed too much power for his own good. He had effectively declared independence, taking unilateral decisions that alienated the board, the Government and the big contractors.

When he was recruited as chief executive two years ago, the organisation was in its infancy, existing only as an offshoot of the Government's NAPCO offices in the Shui On Centre in Wan Chai.

In a symbolic move, Mr Allen soon took the PAA staff away to Central Plaza, as he and his team quickly moved to break away from NAPCO. Once there, Mr Allen began to build up his organisation by hiring hundreds of people: engineers, planners, architects, secretaries and others.

Unlike the organisation it was modelled after, the Mass Transit Railway Corporation, the PAA had no bill making it a full-fledged organisation. It had no track record. It had no ''big brother'' from which to seek help and support - and did not need one as far as Mr Allen was concerned.

Project insiders said Mr Allen isolated the PAA from organisations which would have been willing to assist and support the fledgling entity, organisations including the Civil Aviation Department, NAPCO and the Government Secretariat itself.

There seemed to be a planting of the ''PAA flag'', and a disturbing level of indifference to public and private sector organisations with experience and services to offer.

Mr Allen also refused to talk to the press, creating resentment in the media and leaving Government public relations people to clean up the mess whenever a problem arose.

During the final weeks of his tenure, Mr Allen's policy was to eliminate the term ''Airport Core Programme'', as executed through his public relations staff, in an attempt to have it seem to the public that the PAA was actually in charge of the whole works, not NAPCO.

NAPCO took a dim view of his policies. Schedulers and controllers who were personally committed to the on-time completion of all the airport-related projects made repeated telephone calls to key PAA personnel, requesting information and offering assistance. Often, their calls were never returned.

Serious worries began to build up about the PAA's ability to transform Chek Lap Kok into an airport, in what was perhaps the most demanding time schedule of the entire Airport Core Programme.

Mr Allen was also falling out with the people whom he could not do without - the contractors. A PAA source said the recent refusal by more than 20 of the world's leading consulting engineers to bid for Chek Lap Kok airport design packages was ''the strawthat broke the camel's back''.

The source said: ''Pressure had been building up for months. The consultants' move is the most visible justification to have him ousted.'' Another insider said: ''If you say he was removed because he was autocratic, pushy and tough it would not sound justifiable. But if you can argue his continued presence would have a negative impact on the project, things would be very different.

''If there existed a danger that the airport could not proceed as planned, there would be every reason for the Government to oust him.'' Eventually, through the Airport Development Steering Committee (ADSCOM), messages from NAPCO project controllers were relayed to the Government Secretariat. Because NAPCO is a Works branch, Secretary for Works Mr James Blake took notice. His concern was shared by Mrs Chan and Mr Macleod.

Mr Blake has declined to comment on the sequence of events leading to Mr Allen's departure. ''How it happened is not so important,'' he said. ''We think about the future. The board has made it clear they see the future very positively with Dr Hank Townsend in the chair.'' Meanwhile, Mr Allen left his job as he had begun it - refusing to talk to the press. Many attempts by the Sunday Morning Post to persuade Mr Allen to put forward his side of the matter were unsuccessful.

But one colleague commented: ''He clearly didn't see it coming, or he would have taken avoiding action. It was a sign of his isolation.''