The first Airbus A350-1000ULR flight-test aircraft intended for Qantas’ Project Sunrise programme has completed the longest flight of its development campaign to date. Aircraft MSN707 departed Melbourne and landed in Toulouse on the morning of July 28 after 24 hours and 24 minutes of continuous flight, covering 12,460 nautical miles, or more than 23,000 kilometres.

The flight from Australia was the return leg of a two-part development mission that began on July 23 with a direct flight from Toulouse to Melbourne. The outbound sector lasted approximately 20 hours, while the return to France became the longest flight performed by the development aircraft so far.

MSN707 made its first flight on June 2 and is equipped with specialised instrumentation that allows Airbus engineers to monitor the performance of individual systems under conditions expected on Qantas’ future ultra-long-haul routes. Although the mission was classified as a development flight rather than a certification flight, its results are important for confirming the aircraft’s capabilities before entry into commercial service.

The main objective was to demonstrate that the A350-1000ULR, powered by two Rolls-Royce Trent XWB-97 engines, can complete a flight with a total block time of at least 23 hours, measured from the release of the parking brake at departure to its application at the arrival stand. This provides the necessary operational margin for Qantas’ planned Project Sunrise services, which are expected to involve flight times of up to 21 hours and 40 minutes, in addition to time required for taxiing, holding, possible diversions and other operational circumstances.

Particular attention during both sectors was given to passenger cabin comfort, the performance of the air-conditioning system and fuel management. The A350-1000ULR is equipped with an additional rear centre tank with a capacity of 20,900 litres, enabling flights of almost 10,000 nautical miles.

Airbus test pilot Xavier Pepin, who served as captain on the return flight, explained that much of the additional tank’s functionality had already been demonstrated earlier in the test campaign, but that the remaining checks were completed during this mission.

“We filled the tank to validate all the necessary parameters during the flight, making fuel management and cabin comfort the main focus of the testing,” Pepin said.

During the outbound sector, the crew used the long flight time to stabilise different air-temperature settings and collect the most accurate measurements possible. The return flight was used to complete backup test points that could not be finalised on the way to Australia.

The aircraft’s new twin flight crew rest compartment, specially developed for the A350-1000ULR’s ultra-long missions, was also evaluated. The system consists of two separate sections with individual entrances, allowing pilots to enter and leave their respective rest areas without disturbing a colleague resting in the other compartment.

The rest area was fitted with measuring equipment to monitor ventilation and air-conditioning performance, meaning it could not be used by the pilots for sleep during the flight. Instead, they rested in the eight-berth cabin crew rest compartment located at the rear of the aircraft.

The flight from Toulouse to Melbourne carried four Airbus pilots, two test-flight engineers seated in the cockpit and three additional flight-test engineers working from stations in the main cabin. Airbus test pilot Vincent Sibelle served as captain on the outbound sector and was also responsible for the overall organisation of the mission.

Qantas captains Andrew Coull and David Summergreene joined the crew for the return flight. Both are already qualified on the A350, but the mission gave them their first experience operating the A350-1000ULR variant. A total of five pilots were on board for the return sector, comprising three Airbus pilots and two Qantas pilots.

The route from Melbourne crossed the Pacific Ocean toward Los Angeles, continued over the United States and Canada, then crossed the Atlantic south of Greenland, before passing over the United Kingdom and continuing toward southern France.

A more northerly Atlantic routing was selected to avoid published oceanic tracks used by airlines. Because those tracks might not have been updated by the time the aircraft departed Melbourne, Airbus wanted to avoid potential air traffic control complications or mismatches between flight plans.

Given the exceptional duration of the mission, fatigue management was a major consideration. Pilots were assigned four-hour duty periods, while cockpit crew members rotated every two hours. This meant that each pilot taking over had a two-hour overlap with the pilot being relieved, allowing for a detailed handover and maintaining full situational awareness.

Whenever a Qantas pilot was at the controls, an Airbus test pilot occupied the other pilot seat, as Airbus retained responsibility for the safety and conduct of the development flight.

“We organised the schedule so that the Qantas pilots could take control of the aircraft during selected phases of the flight. They are already qualified on the A350, and this mission gave them their first experience with the -1000ULR variant,” Pepin said.

“We really enjoyed exchanging knowledge and answering their questions during our ultra-long-range journey together,” he concluded.

The A350-1000ULR is being developed for some of the world’s most demanding nonstop commercial routes. Qantas plans to use the aircraft on Project Sunrise services, including direct flights from Australia to Europe and North America, while the MSN707 development flights are intended to confirm that the aircraft can meet the operational, technical and safety requirements of such missions.