The film was shot over 3 days in a real control tower, during its non-operating hours. During the shoot, a plane actually got in touch with the tower during a take. Fortunately, one of the real air traffic controllers was always with the film crew.
Baltazar's (the fish that plays Hugo's only companion in the tower) aquarium belonged to the Director and was flown in from Lisbon. When the Art Department was doing the "put back", the tower crew, who liked it so much, asked if they could keep it. Baltazar now lives with them.
Due to the low budget nature of the project, the whole film was shot in the UK and not in the middle of the Atlantic where the story is set. Exteriors were shot in Beachy Head (England's South Coast) and both Control Tower and Plane were shot in Northweald, a former RAF airfield (North London)