The largest member of the A350 family, the -1000, will not meet its advertised performance goals until 2020 or 2021 without the help of more thrust, fuel and maximum takeoff weight (MTOW), says Air Lease Corp CEO Steven Udvar-Hazy.
"It doesn't have enough thrust," he says on the sidelines of the International Society of Transport Aircraft Trading (ISTAT) conference in Scottsdale, Arizona.
The 350-seat A350-1000, which is due for entry into service in 2015, is slated to have the same Trent XWB baseline engine as the smaller A350-900, but uprated to 93,000lbs (414kN) of thrust to fly 14,800km (8,000nm).
Udvar-Hazy, however, doubts today's specifications for the 73.9m (242ft 5in)-long jet will enable the aircraft to meet its mission, requiring a significant boost to its performance.
"Maybe there will be two versions of the -1000," he says, "The initial version, like on the A340-600 the initial version that had some performance limitations, and after a few years they'll figure out ways to get more thrust, weight, max takeoff weight and more fuel capacity, So there could be a -1000 'Super', but we're looking at 2020 or 2021."
Airbus vice-president of marketing, Andrew Shankland, defends the A350-1000, saying the Trent XWB engine is "certainly sufficient" to power the aircraft. However, he adds there are always "discussions with customers regarding potential changes to any aircraft in the future when you haven't yet hit the detailed definition phase".
The -1000 competes directly with Boeing's 365-seat 777-300ER, which features a 351,500kg (775,000lb) MTOW and 115,500lb (514kN) GE90-115BL engine, providing the aircraft a range of 14,690km (7,930nm).
Udvar-Hazy also says slippage to the overall A350 programme has provided Boeing with "breathing room" to consider its options on how to upgrade the 777.
"I don't think the pressure is as great today on the 777 new derivatives as there may have been, say, a year ago. It's pretty common knowledge that the A350 is not 100% on schedule."
Airbus maintains that the A350-900, -800 and -1000, will enter service in 2013, 2014 and 2015 respectively. The final assembly timeline for the first model, however, has shifted to the close of 2011, compressing its flight test campaign.