Boeing's first 787 test aircraft, ZA001, experienced an engine surge on one of its two Rolls-Royce Trent 1000 engines on 10 September during testing in Roswell, New Mexico, grounding the aircraft and prompting a swap of the power plant.

Boeing says the replacement engine is already in New Mexico and is being installed. The airframer declined to offer a timelime for ZA001's return to flying, though programme sources say the aircraft could return to flying as early as 17 September, with a commencement of test operations the following day.

A programme source familiar with the incident says the surge occurred when ZA001, in a mid-weight configuration, was taxiing to the runway at Roswell International Air Center airport. Crews heard a "loud boom", halting that day's testing. ZA001 has been in Roswell for braking performance and stability control testing during the aircraft's second visit to the airport, say programme sources.

Boeing says it is working with Rolls-Royce to "understand the root cause but initial understanding is that this is an isolated event". The company has not identified which engine had the problem.

Currently, Boeing is determining whether or not this event will have any further impact on the 787's already delayed entry into service.

The airframer announced 27 August it would slide first delivery for launch customer All Nippon Airways to mid-February 2011, citing required inspections, rework of the 787's horizontal stabilizer and the lack of availability of a production engine for Airplane Nine and its extended twin engine operations (ETOPS) testing. Engine delivery delays are the result of a 2 August unconfined failure of a production Package A Trent 1000 engine at Rolls-Royce's Derby, UK facility.

Boeing says the surge has "no relation" to the 2 August incident.

ZA001 has faced engine issues before, having experienced an uncommanded loss of power in February on one of its two engines due to a pressure sensor malfunction, prompting a diversion to Moses Lake Airport in central Washington.

Source: Air Transport Intelligence news