Airbus and Boeing might disagree on any number of points in aircraft economics and market strategy, but both airframers are fully aware of vast potential sales in the narrowbody sector during the next two decades.
Regardless of which airframer has the correct figure for overall passenger aircraft demand - Airbus puts the level at 27,000, Boeing at 32,500 - each forecasts that some 70% of the new aircraft to be delivered during the next two decades will be single-aisle types. Boeing expects a "wave" of retirements for single-aisle aircraft beginning in 2016 as larger numbers of current-generation airframes start crossing the threshold age of 25 years.
Boeing wants limited changes to the 737
That rich market is set against the background of a combined backlog of more than 5,200 single-aisle jets between them. But it is also set against predictions, at least from Airbus, that oil prices will rise to more than $120 a barrel by 2015, and stay there.
Airbus lifted its backlog for the A320 family to more than 3,100 aircraft by the end of August following a string of orders for its re-engined A320neo, the vanguard of its assault on a sector impatient for the fuel efficiencies available from new propulsion technology.
STRAINS IN THE CHAIN
The airframer is probing potential weaknesses in its supply chain as it plans to raise production rates to 42 a month, and explores hiking output further, to 44 and even beyond. "We see some strains [in the chain] today," says executive vice-president for programmes Tom Williams. "But some of those would have happened at any build rate."
Having avoided the temptation to reach, perhaps over-reach, for an entirely new aircraft design, Boeing - whose 737 backlog stands at a healthy 2,200 - has opted instead to re-engine its own ubiquitous twinjet.
In the months after launching the A320neo, as commitments rose into four figures, Airbus teased Boeing over its apparent indecisiveness, and the cat-calling did not stop when the new 737 Max was unveiled.
Airbus chief operating officer for customers John Leahy scorned Boeing's initial claims of nearly 500 commitments, pointing out that little appeared to have been defined.
"I don't quite know what it is right now," he said. "There is no fan diameter size, engine thrust size, take-off weight or empty weight, or take-off performance. As soon as they write a spec and decide what the airplane is, then I'll have some comments on it. But I can't comment on something that doesn't exist."
However, potential customers appear to be satisfied the aircraft's capabilities will become clear within a few weeks. Lessor Aviation Capital Group expects the 737 Max to have better definition by about mid-November, and has expressed strong support for the programme.
Boeing has asserted that, even without re-engining, the 737 will be able to hold its own against the A320neo through improvements by 2016. With the 737-8 Max it promises a 4% fuel-burn advantage on its rival. Boeing Commercial Airplanes vice-president of marketing Randy Tinseth says: "We believe we'll be able to hold a 7% cash-operating-cost advantage over the competition. It's about 8% today."
Central to the competition will be the powerplant. Boeing has opted to retain its exclusivity pact with CFM International, which will supply the Leap-1B engine for the Max family. But the 737's low-set fuselage, already responsible for the characteristic shape of its engine nacelles, has created an issue over the degree to which the airframe would have to be modified to accommodate a fan larger than the CFM56-7's diameter of 1.55m.
Whether Boeing opts for the 1.68m or 1.73m fan, it will be substantially smaller than the 2.06m or 1.98m fans on the PW1100G and Leap-X respectively for the A320neo. Boeing chief Jim Albaugh said the airframer wanted to "limit the scope" of structural modification to the 737. While the airframers have produced numbers and counter-numbers over the forecast fuel savings, it has been left to customers to estimate the pros and cons attached to each engine.
Air Lease Corporation chief Steven Udvar-Hazy told the ISTAT Europe conference, held in Barcelona in September, that Pratt & Whitney's geared turbofan would probably result in the better fuel consumption, while the CFM rival - with its less-revolutionary but nevertheless updated technology - would bid to maintain a maintenance cost edge. Udvar-Hazy said this broadly reflected the current situation between the CFM56 and International Aero Engines V2500 on the A320 - the V2500, he said, had a 1-2% better fuel-burn but the CFM56 had longer on-wing times.
"We're all gamblers on what the true maintenance cost will be," he added. "Only after some five to eight years in service will the actual picture emerge."
P&W became the lead engine for the A320neo and experienced an initial surge of sales, but was subsequently caught and overtaken by CFM by the close of the Paris air show. Airbus intends to put the A320neo into service in October 2015 - the P&W engine on the type will precede the CFM powerplant by nine months to a year - while the A319neo will follow six months later, and the A321neo another six months after that. The 737 Max will enter service in 2017.
The A321neo is Airbus's weapon to pursue the Boeing 757-200 retirement market, although there is still a question over the A321neo's ability to offer satisfactory range, while Boeing is keen to offer a suitable counter through the 737-9 Max to prevent Airbus eating too far into the sector.
Airbus's latest advance towards the A320neo will be the development of the sharklet wingtips, scheduled to fly on an A320 before the end of this year, although the airframer has admitted years of modifications to the original airframe being used as a test bed has resulted in hold-ups and snags while it deals with fitting the sharklets.
Selection of P&W's PW1100G for the A320neo has demonstrated confidence in the new engine which might provide a side-benefit to the Bombardier CSeries, which has been nudging into the 110- to 130-seat territory previously occupied by the 737-600/700 and A318/319. Bombardier is facing two hurdles as it attempts to step into the big league. Near-term demand has been scant, although the airframer has managed to place a few high-profile names such as Swiss International Air Lines and Korean Air on its customer list. Its other concern is the waning interest in its CRJ and turboprop lines, which places extra onus on the CSeries to be successful.
Bombardier hopes there is room for its CSeries to meet the demand of niche regional carriers
RBC Capital Markets surveyed several potential customers and concluded that while customers were positive about the CSeries, they were reserved about taking on a new type and were adopting a "wait-and-see" attitude before translating interest into orders. Bombardier's target of 300 orders by late 2013 entry into service, RBC added, was looking doubtful. While perhaps not the emphatic endorsement Bombardier might have hoped for, the survey also suggested that - even if the mainline market barrier proves too high - there is room for CSeries to meet the demand of niche regional carriers less concerned over fleet commonality and in need of specific characteristics, which the airframer claims the type will offer. All of which Embraer will be noting closely. If Airbus and Boeing - willingly or otherwise - cede the low-end market sector, it seems unlikely the Brazilians will simply stand by and watch.