The US FAA has cleared the Boeing 747-8 to operate at airports with parallel runway and taxiway centerline distances identical to that of its smaller predecessor, the 747-400, despite its bigger wingspan and taller vertical stabiliser.

The FAA determined that the Boeing 747-8, which is classified as an Airport Design Guidelines (ADG) VI category aircraft, can operate to the ADG V standard taxiway/runway separation distances.

In a 12 March memorandum from FAA's Airport Engineering Division, to Airports Regional Division Managers, the agency said the 747-8 can operate on ADG V parallel runway and taxiway centerline distances, "as long as the tail height is within the ADG V limit of [20.1m (66ft)]".

The 747-8's tail stands at 19.5m (64ft 2in), compared to that of the 747-400, which is 19.4m (63ft 8in).

ADG V standards dictate that the centerlines distance between parallel runways and taxiways must be 191.9m apart, taking into account airport elevation, in Category I instrument approaches with visibility minimums down to .8km (.5mi), and 152.4m apart for Category II and III approaches with visibility less than .8km.

The ADG VI standards for runway/taxiway centerline separation, which the larger Airbus A380 must operate under, dictate a 152.4m separation in visibility of .8km or greater and 167.6m for visibility less than .8km for Category II and III approaches.

The 747-8F is expected to enter service in the fourth quarter of 2010 with Luxembourg-based Cargolux.

Source: Air Transport Intelligence news