SINGAPORE AIRLINES, the lead airline for the Airbus A380, has signed a letter of intent to purchase up to 31 Boeing B777-300ER (extended range) aircraft. General Electric GE90-115B engines will power the twin-engine aircraft. The order reinforces SIA's standing as the largest customer for the Boeing 777. SIA presently flies 55 B777s, and has another four B777s on firm order. With this latest order, the number of B777s in the SIA fleet will eventually reach 77 aircraft. The B777-300ER, seating about 350 passengers and with a range of 7,000nm, will be deployed on SIA's long haul and medium-haul routes. The new order will allow SIA to achieve capacity growth of between 4 and 6% a year. At the same time, it will maintain SIA's fleet as one of the industry's youngest, as the B747-400 is progressively retired.