Extending the horizon: Inside the A350-1000ULR’s longest development flight

On 23rd July the first A350-1000ULR flight test aircraft MSN707 embarked on its longest point-to-point flight from Toulouse direct to Melbourne, Australia. Then a few days later it flew all the way back with two Qantas guest pilots on board, landing in Toulouse on the morning of July 28th. To find out more about this impressive undertaking, we sat down with Airbus Test Pilot, Xavier Pepin, who captained the aircraft on its longest ever flight - covering a distance of 12,460nm in a flight time of 24 hours and 24 minutes!

A350-1000ULR Qantas MSN707 - Back from Australia - Arrival

Aims of the long range flights with MSN707

This flight-test aircraft, MSN707, which first flew on the 2nd June is equipped with specialised instrumentation and is now really ‘stretching its legs’ for the first time. Its two-part voyage is technically classified as a ‘development’ flight test (as distinct from a ‘certification’ flight test). 

The goal is to demonstrate that the aircraft, powered by two Rolls-Royce Trent XWB-97 engines, can perform a 23-hour ‘block time’ flight. This is the duration from releasing the parking brake at departure to setting it at the arrival stand – to ensure coverage for the customer’s intended 21 hours 40 minutes flight time (plus holding, diversion and taxi times at departure and arrival), for its forthcoming “Project Sunrise” routes.

In particular, the mission also serves to validate cabin comfort through air conditioning (ATA Chapter 21) measurements and fuel management systems (ATA Chapter 28), particularly the additional rear center tank (RCT) – with a 20,900 litre fuel capacity – which enables ultra-long-range (ULR) flights to cover a distance of almost 10,000 nm. 

Xavier explains: “Whilst we have already demonstrated much of the RCT’s functionality earlier in the flight test campaign, we finalised some remaining test points in these long range flights. So we filled this tank to validate all necessary parameters during the mission, making this, along with cabin comfort, the primary focus of our testing.”

He adds: “During the first leg we also made use of the time (the flight lasted approximately 20 hours) to stabilise various air temperature settings to ensure accurate measurements. So while much of the testing goals were already tackled on the outward leg, the second leg addressed any backup test points that were not completed during the first leg.”

Furthermore, the crew evaluated the ULR’s new twin Flight Crew Rest Compartment (FCRC) – which was extensively instrumented to measure the air conditioning performance. This new  module, specially designed for the -1000ULR’s ultra long missions, features two separate, dedicated sections with individual entrances. This modification ensures that in airline operation pilots can enter or exit their respective rest areas without disturbing one another.

A350-1000ULR longest flight cabin FTE

Flight crew roster and routing aspects

For the outward leg there were four Airbus pilots, with Test Pilot, Vincent Sibelle, as captain (and also being responsible / in-charge of the overall mission organisation). The other three pilots on board were  Xavier Pepin, Josef Bayoud and Chetan Takalkar. In addition to these pilots, the crew included two Test-Flight Engineers (TFEs), Laurent Rossignol and Nicolas Granier, who were seated in the cockpit to monitor aircraft systems and three Flight-Test Engineers (FTEs), Tuan Do, Alexia Plumet and Jaime Angoloti, who were seated at their flight test work stations (in the main cabin) to coordinate all tests including cabin comfort and fuel monitoring. 

For the return leg – from Melbourne back to Toulouse – Airbus Test Pilot, Xavier Pepin, was designated as captain. Moreover, for this leg two Qantas pilots Captain Andrew Coull and Captain David Summergreene joined the crew and one of the Airbus pilots disembarked. So all in all, on the return flight there were five pilots on board – comprising three Airbus pilots plus the two Qantas pilots who are already qualified on the A350 but who were new to the ULR variant. Meanwhile, the two TFEs and three FTE’s were the same as for the outward flight.

This even longer flight involved taking off from Melbourne, crossing the Pacific toward Los Angeles, traversing the US and Canada, and then crossing the Atlantic south of Greenland, then over the UK and back to southern France.

Xavier explained that for the return flight a northerly Atlantic path was chosen to avoid the published tracks in use by airlines that might not be updated by the time of takeoff, thereby avoiding potential Air Traffic Control (ATC) issues, such as mis-matching flight plans.

Fatigue management and crew rest during the flight

Xavier recalls: “To manage fatigue during the 20 to 23-hour flights we implemented four-hour shifts for each pilot, but we rotated the crew every two hours. This staggered approach ensures that when a new pilot joins the cockpit, they overlap for two hours with the outgoing pilot. This facilitates a thorough handover and maintains full situational awareness. Additionally, for the second flight leg, at least one Airbus test pilot was always seated in a pilot seat when a Qantas pilot was in the other seat to ensure mission safety, as Airbus holds responsibility for the operation. We have applied this same structure to manage rest periods effectively.”

Notably, because the aircraft’s new ‘twin’ flight crew rest compartments were ‘occupied’ with ventilation measurement equipment, the crew used instead the eight-berth cabin crew rest compartment at the rear of the aircraft for their sleep.

“In the rear cabin crew rest compartment, since there weren’t any passengers or cabin crew, we could quickly return to the cockpit or FTE station at any time if needed,” notes Xavier.

“We have organised a schedule to allow a Qantas pilot to take the controls at specific times. These pilots are already qualified on the A350, and this mission provided them with their first experience with the -1000ULR variant.”

“We really enjoyed and appreciated exchanging knowledge and addressing their questions during our ultra-long-range voyage together,” he concludes.

A350-1000ULR Qantas MSN707 - Back from Australia - Arrival