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May 24, 2024
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Airbus is (still) unwilling to specify the exact impact of the requirements from regulators on the A321XLR and how it will affect the design and specifications of the aircraft. Head of Program Gary O’Donnell said during a First Flight media event in Hamburg on June 15 that each of the requirements will need to be reviewed in the run-up to the final certification of the XLR. The requirements focus on the one aspect that makes the XLR different from the other A321neo models: the Rear Center Tank. Airbus reticent on tank redesign on A321XLRs first flight-day.

Airbus invited media to Hamburg to witness the maiden flight of the first of three A321XLR Flight Test Aircraft from its Finkenwerder facilities. The aircraft, registered F-WXLR with manufacturing serial number MSN 11000, took off at 11.05 am local time. The flight was expected to last up to four hours at different flight levels, including FL100 for confirming the initial configuration, general handling qualities and flutter pulses, a go-around at Finkenwerder, and the final landing. For the first three hours, the aircraft maintained FL150 while flying West and East of Hamburg. Only in the final hour, the XLR climbed to FL310. After four hours and 35 minutes, the aircraft was back in Finkenwerder. The test crew of five consisted of two pilots (Thierry Diez and Gabriel Diaz de Villegas) and three flight test engineers ({Philippe Pupin, Mehdi Zeddoun, and Frank Hohmeister).

Test program

The XLR flight tests program will consist of three aircraft, as reported earlier by AirInsight. MSN11000 has CFM LEAP 1A-engines. It was handed over to the flight test team on June 3 and did the first engine runs on June 6. Engine High Power tests were done on June 8 and the Rejected Take-Off until 100 knots on June 13. The aircraft is fully equipped with the latest iteration of digital flight test instrumentation and has a workstation for two engineers. Also onboard are water tanks for the various center of gravity configurations.

Flight Test Aircraft 1 is prepared for its maiden flight in Hamburg. (Richard Schuurman)

MSN11058 is FTA2 and will be fitted with Pratt & Whitney PW1100G-AM engines. Only at a later stage, the XLR will get the Geared Turbofan Advantage that P&W is developing to enter service in 2024, but this is unrelated to the XLR test program, said O’Donnell. The aircraft has completed final assembly and is currently fitted with flight instrumentation before joining the flight test campaign in the coming months. MSN11080 is the third aircraft but the first with a full Airspace cabin and only limited test instrumentation. It will have CFM engines again. MSN6839, a normal A321neo, has been used in the past months to test the braking system of the XLR, which is modified in order to cope with the higher 101.000 tons Maximum Take-Off Weight (MTOW). The main gear is also different, having just a single shock absorber compared to two on the previous design. The aircraft structure has also been reinforced significantly above the tanks.

Other changes to the XLR are a different fuel line system with inerting adaptations, bigger water and waste tanks, a single inboard trailing flap on the wings, updated cabin systems for more comfort, and an electronically-controlled rudder. 

Tanks concerns

Since its launch at the 2019 Paris Airshow, the A321XLR has won over 500 orders, says Airbus. According to Aviation Week, the exact number is 506. To main reason that airlines and lessors have committed to the type is the extra range of the XLR, which can do 4.700 nautical miles/8.700 kilometers and is ideal on extra long routes that might be too thin for a widebody but interesting enough not to do.

The XLR gets its extra range from the Rear Center Tank (RCT), which is just aft of the wing in between Stations 15 and 17 and can contain 12.900 liters. The RCT has the capacity of three Additional Center Tanks (ACT) that are optional on the A321LR and can be fitted or removed overnight. Optional to customers on the XLR is an additional Forward Tank of 3.120 liters, which together offer the type its 8.700 km range. O’Donnell said that fifty percent of the XLR customers have selected the forward tank as well to get the maximum range.

But the RCT is in the focus of media attention for over a year, since Boeing reportedly brought the design specification to the attention of the regulators in late 2020. Which included its concerns about fire protection, the effects of the cold fuel on cabin comfort, and its robustness to withstand hard landings.

Gary O’Donnell said that Airbus has been working with EASA on the specifics of the tank for three years, stating that the regulator is fully aware of all the details of the design. This includes a ‘normal gap’ between the upper side of the RCT and the floor and to other systems as well as insulation and fire protection.

F-WXLR on her way to the runway at Hamburg Finkenwerder to commence her first flight. (Richard Schuurman)

In May, Airbus cited ‘certification requirements’ from the regulators as the reason to defer the certification/entry into service of the XLR by a few months from late 2023 to early 2024. But like then, when CEO Guillaume Faury was unwilling to elaborate on the extent of the requirements, Even when pushed by media, O’Donnell only said: “Basically, we have been in discussions with EASA for three years, as we do with every project, so this is nothing special. And we will continue to work with them until the day we get the type certificate. Each of the features that make the XLR different from the other models as the RCT, cabin systems, the landing gear, and also the fire suppression of the tank, needs to be reviewed. That is something that EASA asks us to do.” Which isn’t strange, O’Donnell says, as the XLR is the first single-aisle Airbus aircraft to have a Rear Center Tank.

He continued: “We are not at the end of the flight test program. If we find things, we will address them, which is the normal development process. We are sixty percent through the process, forty percent still needs to be done.” O’Donnell added that Airbus can tap into a raft of options to meet additional RCT safety requirements if there will be any, including adding Kevlar or fire protection.

That’s why Airbus is unable (and unwilling…) to say if the XLR’s unique selling point – its range – will be affected by any eventual regulatory requirements. Something that somebody in Seattle might be very keen on to see, as a reduced range for the XLR will eat into its sales success.  

Flight test engineers Frank Hohenmeister (front) and Philippe Pupin in the XLR, sitting at the work station in preparation for the first flight. (Airbus)

Three cabin configurations

Airbus is offering the A321XLR with three-cabin configurations. One has 174 seats, including 12 First Class, 24 Business Class, and 138 Economy Class seats. The other has 187 seats, of which 16 in First, 16 in Business, and 171 in Economy. A single-class version is offered with 240 seats.
At the Aircraft Interiors Expo in Hamburg this week, various suppliers are showing new premium products for single-aisle aircraft that could transform their flying experience on them. JetBlue’s Mint suites on the A321LR are an example of what to expect. How these premium seats will affect aircraft weight and range is too early to tell, says O’Donnell, but he expects this to be limited.

Work was interrupted at Airbus Hamburg to watch the take-off of the A321XLR. (Richard Schuurman)

Initially, the XLR will be produced in Hamburg, to be followed at a later date in Mobile (Alabama). Production in Toulouse in the reconfigured Jean-Luc Lagardere final assembly line is optional, says O’Donnell. Airbus said last year that assembly would be at multiple sites.

author avatar
Richard Schuurman
Active as a journalist since 1987, with a background in newspapers, magazines, and a regional news station, Richard has been covering commercial aviation on a freelance basis since late 2016. Richard is contributing to AirInsight since December 2018. He also writes for Airliner World, Aviation News, Piloot & Vliegtuig, and Luchtvaartnieuws Magazine. Twitter: @rschuur_aero.

1 thought on “Airbus reticent on tank redesign on A321XLRs first flight-day

  1. Gary, you are working in a very important position towards making Airbus flights safer & easier. As a cousin of your dad,I did meet you when you were a lot younger and I am so proud of you.
    Your Aussie Cousin,

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