Does the Airbus A321 have the X(LR)-factor?

One of the great will-they-won’t-they topics of recent years within commercial aviation is Boeing’s plans to launch a new aircraft that would effectively be a successor to the 757 – the last of which was delivered in 2005, for what is now referred to as the middle-of-the-market.  This new model, also called the NMA, or even pre-emptively the Boeing 797 has been on the cards since 2015 and is being pitched to plug a perceived capacity gap in the 220 - 270-seat segment.  This gap sits roughly between the capacities of Boeing and Airbus’ largest single-aisle aircraft, the Boeing 737-10 and Airbus A321neo, and their smallest twin-aisles: the 787-8 and A330-800.  The intended range for the new aircraft is about 5,000nm (9,260km).

While Boeing continues to determine the final performance attributes of its proposed aircraft offering, Airbus has been pushing it’s A321 to the right, in terms of payload and range capability. By extending the envelope even further with the proposed A321XLR, Airbus’s intent is to squeeze Boeing from the bottom of the NMA market

Back in 1994 when the first A321-100 entered service with Alitalia, the aircraft could carry 185 passengers and luggage over a typical range of 2,300nm (4,260km).  Fast forward some 25 years and the latest variant to be offered – in the shape of the A321neoLR – will provide a maximum seating capacity of 244 passengers and a range of around 4,000nm (7,410km), when it is scheduled to enter service in 4Q 2018.  Programme development has not stopped there, with Airbus looking to further enhance the capability of the A321 to compete squarely with Boeing’s proposal.

The driver for this is influenced by low cost carriers which are expanding their route networks to cover longer range sectors.  Rather than spending billions on the development of a completely new aircraft programme, Airbus have found themselves, in the shape of the A321 and A330, with a philosophy (unintentional or not) that Boeing had itself created some 40 years ago with the joint development of the 757 and 767 – the very aircraft any NMA or A321XLR is potentially seen as ‘replacing’.  There is an argument to say that Boeing made such a good job of the capabilities of the 757 and 767 that they have proven a challenge to surpass, even after all this time

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Adapting the A321 design to meet the range

While Airbus has not released any specific details of the proposed changes to further enhance the capability of the A321LR, an announcement looks likely to occur in 2019, with an entry-into-service date in the 2021-2022 timeframe, well ahead of Boeing’s 2025 ambition.

The target range of any XLR is seen as 4,500nm (8,335km) or more.  Such a move would allow airlines to operate the aircraft, for example, on longer transatlantic services from airports further eastwards in Europe to destinations farther down the US East Coast.

Questions remain as to how the additional range can be achieved through modifications to the existing design.  Certainly, the size of the centre fuel tank can be increased to achieve this, which could gain up to around half the target amount.  If the proposed timescale is critical, then radical changes to the fuselage, in the form of a plug for improved capacity or a completely new wing of a composite construction, would increase any test and certification timescale.  A larger wingspan (possibly through folding wings) and a wingbox using CFRP (carbon fibre reinforced plastic) material could meet the development schedule, while simultaneously saving weight.  If more range is needed, then an increase in wingspan is one of the natural options as this improves efficiency on longer flights.  It also allows the ability to carry more fuel, in addition to the larger centre tank.  Squaring the circle means doing this with existing engines, without a reduction in payload capability – something that airlines are likely to resist.  Some aerodynamic improvements and a strengthened landing gear would also likely be required for aircraft reaching an MTOW of upwards of 100t (220,500lb).

From an airline operational standpoint, a long single-aisle has the disadvantage – certainly in the eyes of LCC airlines – of making fast turnarounds difficult.  The offloading, and then loading, of passengers with the obligatory cabin baggage cabaret – a process of the airlines’ own making – requires more time at the gate for longer-haul routes operated by single-aisle aircraft, and the requisite refuelling.  Boeing’s concept of a small twin-aisle for the NMA would improve matters in this respect, but that does come with a drag penalty.

 

The Ishka View

 

The debate remains about whether this mid-market segment exists in sufficient commercial quantity; can it be considered in isolation; and if so, how should it be served.  Boeing certainly appears to be heading down the path of a new design, split between a smaller and larger version, but of course until the manufacturer releases details, we can only surmise.  Unlike Boeing which has Maxed out the 737, Airbus is content to further develop an existing product; and that it will be competitive enough to keep the airlines interested.  It is undoubtedly the safer bet from an R&D standpoint.

There is of course a train of thought that all of this is a sideshow by Boeing as a prelude to launching what would be a direct replacement for the 737.  Whatever the outcome, the longer it takes for Boeing to deliberate on the formal launch of a mid-market aircraft (or not), the more it will help Airbus take a greater proportion of this segment of the market over the next five to 10 years. For the time being, Airbus, which is unlikely to be the first mover, seems content to play the waiting game and respond to whatever Boeing comes out with before choosing to commit itself.

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