The very long-range capability of the new twins, particularly the 777-200LR, which is expected to resume development in the second quarter of this year, means rigorous emphasis on the extended-range twin operations (ETOPS) test phase.
A total of 40 ETOPS proving flights are due for the two test aircraft, with WD501 assuming the lion's share with 24 of them. Both aircraft will each fly at least four legs, including 330min flying on only one engine. This means the programme will comprise a combined total of 22h single-engined flying time.
Eleven simulated diversion missions will be flown, two across the South Pacific, two on the North Pacific, one over the Atlantic, two over the Poles, one on the USA to New Zealand, route and two in the southern hemisphere.
WD501 will be focused on ETOPS systems, functions and reliability trials, but it will also undergo humid weather tests. Routes planned for the first aircraft include Seattle-Auckland-Singapore-Seoul-Irkutsk-Yakutsk-Petropavlovsk-Kamchatsky-Seattle, as well as return flights from Seattle to Reykjavik and Paris.
The aircraft, which is expected to complete a 13.3h flight as its longest single mission, is also due to fly Seattle-Easter Island-Lima-Miami-Iqaluit-Seattle. WD501 is scheduled to complete ETOPS tests by the end of December.
WD502, which adds electromagnetic interference testing to its duties on top of the standard ETOPS tasks, has a shorter test schedule, but the longest single flight time at 19h. It will also perform one flight with the integrated drive generators switched off for 7h.
The aircraft's planned test flights include Seattle-Cold Bay, Alaska-Tokyo-Taipei (with a Taipei-Wake Island return flight), and Taipei-Singapore-Dubai-Johannesburg-Perth-Sydney-Rio de Janeiro-Miami-Seattle. WD502 is due to complete its ETOPS test programme by early December.
Source: Flight International
