Aerial drama.

The clarity provided by the big hall of this airport makes the passage from land to air travel direct and reassuring.

The new passenger terminal at Hamburg airport adds to and brings up to date a rather shambolic and run-down complex, and at the same time is intended to give an appropriate sense of drama to air travel. Hamburg is not a very large airport (though it has quite a heavy throughput of charter traffic). It now has facilities for dealing with up to 11 planes simultaneously, of which three can be for international flights.

The organisation of the new terminal is fundamentally very simple. Ground level is for baggage handling and arrivals. The first level is devoted to departures, and the main dramatic move of the building is the departure hall which is reached from the raised roadway on the land side. Once through the porches, the huge space swoops forward, up and away to the view of the sky over the runways to the west. The lightweight metal roof is supported on seven triangulated curved trusses, which themselves are supported on arms that stretch out to carry loads down to rows of six massive concrete pylons at each end of the space. So you enter through the forest of diagonal arms, to be enveloped by the great 75 m by 101 m clear space, which is much higher on the air side because the architects have piled two trays of shops and restaurants over the security gates which lead to the planes. The sectional strategy is very similar to the same firm's Stuttgart airport (AR May 1991), and it allows the commercial concessions (which often contribute much to the visual and circulatory chaos of airports) to be lifted clear above the main level. But at Stuttgart, the roof is supported by elegant tree-like steel structures which help break up the space visually.

In contrast, Hamburg's great open volume can seem a bit daunting, particularly if there are not large numbers of charter-flighters queuing at the rows of check-in desks. But there can be no doubt about the direction in which to move, the trusses themselves give the space a sense of urgency and thrust. Their white members are honed to minimal sections, so they provide little obstruction to the light from the glazed parts of the roof which are defined by the trusses' top booms.

The architects intended the whole space to be full of daylight, and in this they have succeeded triumphantly, for the effect of the skylights is complemented by the glazing on the west side and by glass over the office wings that contain the space to north and south. (Externally, these rectangular blocks are something of a disappointment; their dumb Ungers-Rationalist treatment makes them no more than a couple of rather dull book-ends.) At night the luminosity of the departures hall is reversed with uplight from the sides, the tops of the check-in desks and special cylindrical services pylons on the internal terraces at the west end.

The perceived thrust of the space is augmented by glimpses of the planes and the sky past the air-side checkpoint (something that Foster wanted to achieve at Stansted, AR May 1991, but he was thwarted by the obsessive security authorities.) Once through the checkpoint, the whole airport is laid out in panorama, with the planes almost immediately in front. The three international departure lounges with their bridges to the air jetties are immediately ahead. To the right is a long pier which stretches and curves out to the north to contain similar domestic departure facilities mostly reached by travelators.

Externally, the long glazed wall of the pier, shaded by a lightweight metal brise soleil and punctuated by the gay red bridges, forms a mask to the chaos of the old complex and unites it to the new work. It is this facade that greets arriving passengers who proceed down escalators to the international and domestic arrival areas, from where they go to baggage reclaim, then on to the long thin arrivals hall under the raised road. In a deft stroke, the architects have cut a semi-circular void in the floor of the departures hall which allows the big volume to be appreciated (and attained up escalators) from the lower level.

It seems that at least small and medium-sized airports are beginning to acquire a typology of their own, with simple and direct circulation patterns, clear directionality between aeroplanes and land transport - and a degree of grandeur and drama in their main spaces. Hamburg is a step in the evolution of the type.