Mission impossible?

The ATMR was pitched head to head with the single-aisle 200-seat 757 that had been launched by Eastern Airlines and British Airways but offered a range of new technologies with a corresponding improvement in operating economics.

And in another twist the 757 replacement will likely be the basisfor a 737 replacement with a longer 240-seat model coming first and the ‘baseline’ 200-seat aircraft coming later next decade.

The quandary that Boeing finds itself in is possibly one of the most complex in decades because the 757 replacement market itself does not justify an all‑new aircraft and the 737 is selling in record numbers.

Officially, Boeing calls the 757 replacement the middle-of-the market (MOM) and the 737 replacement the new-small-airplane (NSA).

Senior vice president of Boeing Commercial Airplanes John Wojick told media at this year’s Paris Airshow that airlines are looking for an aircraft that is slightly larger and can fly slightly further than a 757. “So they want an airplane about 20 per cent larger and with a 25 per cent greater range than a 757,” he explained. The problem is those demands – tough in any circumstance – make a single family option, including a 737 replacement, a major challenge.

Boeing has already ruled out developing the 737-9 MAX to compete with the A321neo LR due to ground engine clearance/rotation issues.

The 757 itself came in two versions: the two class 200-seat -200 and the 243‑seat -300. The larger model is certified to carry 295 in a one-class configuration and in a Thomas Cook layout carries 280. However, the 757‑200 proved far more popular, and in two and three class configurations seats between 180 and 190.

By comparison the Airbus A321 in a British Airways European configuration seats 184 and in aninternational layout 154, including 23 flat beds.

Mission possible?

The man charged with coming up with the dream machine(s) is Mike Sinnett, vice president of product development for Boeing Commercial Airplanes. He indicated to Australian Aviation at the Paris Airshow that one option is to develop both the MOM and NSA in parallel, sharing common cockpits, systems and structures to cut costs. He also hinted that they “could be” from the same family. But he is quick to emphasise that the design space is wide open with all options on the table.

Boeing Commercial Airplanes President and CEO Ray Conner agrees, telling Australian Aviation that at this stage it is not clear what the 757 replacement will look like but adds the project is high on the agenda. “We are looking at this very closely,” he said.

While senior vice president, global sales & marketing John Wojick adds that the big issue is operating cost performance with airlines demanding single-aisle economics, back in 1980 that was not a big issue, according to Boeing legacy company McDonnell Douglas.

In its brochure “A First Class Experience – At Economy Fare” extolling the virtues of its twin-aisle ATMR 757 competitor, it stated that it only required one passenger per trip to offset the weight and drag of the additional aisle.

MDC also claimed that the 178-seat mixed class ATMR would have a fuel burn 24 per cent lower than the 757. According to the presentation the ATMR, later dubbed the DC-11, would have 14 first class seats at a 38in pitch in a 2-1-2 configuration and have 168 economy seats at a 34in pitch in a 2-2-2 configuration.

At this stage it is not clear what the 757 replacement will look like.

The passenger appeal of a twin-aisle 2-2-2 aircraft needs no explanation. Aside from the basic comfort there is the speed of boarding or deplaning, not to mention the additional overhead luggage space.

With the push by passengers to bring all their luggage into the cabin the boarding of single-aisle aircraft has become a major headache with airlines forced to allow up to 30 minutes for the boarding process in the US and Canada. And that trend is spreading. Those times wipe out the low-cost airline model’s 30-minute turnaround.

The ATMR cross-section was just 55cm wider than a 757 but 49cm narrower than the Boeing 767. These cabin dimensions allowed for 17. 7in‑wide seats and an 18in aisle.

Any new twin-aisle design would certainly be wider again to permit, say, 18. 5in‑wide seats and an 18in aisle and for those airlines which insist on cramming as many passengers as possible into their aircraft there is also the option of taking out one aisle and fitting a 4-3 configuration.

While it may seem inhumane to suggest such a thing, most large passenger ferries have cross-sections that resemble crammed picture theatres. And this option would satisfy the extreme cost-sensitive part of the market and help justify the investment in an all-new design.

A trade-off, however, could be that the LCCs give their passengers an inch more legroom which would cost them one seat row of seven for an overall 26‑passenger gain in a cabin with 33 seat rows such as a Ryanair 737-800. The cabin layout could be a mix of twin-aisle at the business/premium economy end and single aisle at the budget economy section.

Boeing says it has the tools and IP to move forward with the design from an airframe technology perspective. Wojick told media that “anything we do in any marketplace going forward is going to rely on technology we found and implemented on the 787 and 777X. ”

Missed opportunity

McDonnell Douglas baulked at launching the ATMR/DC-11 despite having an order from Delta Airlines for 60 aircraft in its pocket.

Delta really wanted the DC-11 but MDC wanted another airline on board at launch and larger progress payments to help its cash flow. Then senior vice-president of Delta Robert Oppenlander summed up the situation in the December 1 1980 edition of Business Week: “They (MDC) wanted to launch a new plane without taking any risk. That isn’t the way it works. ” (Interestingly, before it merged with McDonnell, Douglas Aircraft Company launched the DC-9, its most successful jet, with no orders. ) Balancing that view, John McDonnell defended the decision – the first to be made after his father James ‘Mr Mac’ McDonnell died. He explained that after deregulation, airlines were not as sure about what size plane they wanted. “Recently, we have been hearing that 150 seats or even 120 seats is the right size,” he told Business Week at the time.

Any way you look at it the DC-11 was one of the most exciting aircraft proposed by McDonnell Douglas. Using the very latest technology, including composites for the floor beams, control surfaces, nacelles, vertical and horizontal stabilisers and other primary structures, MDC predicted fuel consumption 20 per cent below that of the DC-9 Super 80, later renamed the MD-80, using the JT10D-32 engine rated at 32,000lb thrust. Essentially, the DC-11 would incorporate the very latest technology whereas the 757 was built around existing proven concepts. The DC-11 featured a high aspect ratio aft cambered wing, wing load alleviation and three-position slats and double-slotted flaps. On the flightdeck electronic displays and full ARINC 700 avionics were planned.

In the company’s presentation much was made of the increasing size of passengers with one graph showing that between 1955 and 1980 male shoulder width had increased by one inch and female by just over 0. 5 inches.

It also polled passengers as to what was most important to them and the results are no different to today. Wider seats topped the poll at 24. 6 per cent followed by more legroom at 20. 8 per cent and morecarry on facilities at 17. 5 per cent. And these results were at a time when the standard economy seat pitch was 34in! Interestingly, MDC looked at a slightly different double bubble cross‑section to enable the DC-11 to take LD3 containers, increasing its revenue generation potential. The overall drag penalty was put at three per cent.

Boeing also toyed with the twin-aisle concept with its 7J7 and a full cabin mockup was shown at the 1987 Paris Airshow.

It took the twin-aisle concept further with a 4. 8m cabin width that would permit 2-3-2 seating, 17in-wide seats and 18in aisles in economy.

It would be powered by rear-mounted unducted fans, but later Boeing looked at a wing-mounted International Aero Engines Super Fans, an engine that was originally to be fitted to the A340 but was dropped due to technology issues.

Boeing assembled an international team to build the 7J7 including the Japanese heavies, Short Brothers, SAAB Scania and Australia’s Hawker de Havilland.

Head of the 7J7 program was Alan Mulally, who would later rise to be president and CEO of Boeing Commercial Airplanes and later president of Ford Motor Company.

Like MDC, Boeing polled over 2,500 frequent flyers after they toured the 7J7 mockup and the layout received an overwhelming thumbs up.

And then chairman of SAS Jan Carlson wanted to be the launch customer. “If Boeing provides more passenger-pleasing features in the 7J7 we’d like to be the launch customer,” Carlson told media at the time. “Nobody wants to sit in the middle seat,” Carlson said in a 1986 interview and nothing has changed since then. Referring to the standard

The DC-11 was one of the most exciting aircraft proposed by McDonnell Douglas.

3-3 configuration, Carlson added that “it’s a shame for the industry that there have been so few changes inside new planes. ” Despite strong interest, the relatively low price of fuel at the time did not justify the investment and the project was slowed in 1987, although it did have a brief resurrection in 1991.

Boeing went on to launch the 737NG to meet the sales success of the A320.

MDC would also resurrect the twin-aisle 200-seater concept in 1991 with what it called at the time the MD-XX, which was pitched at a 1996 launch, although a version with fewer technological advancements could receive a go-ahead in 1993 it told media. The MD-XX designator would later be attached to a development of the MD-11 that was also cancelled.

Modular solution

Interestingly, in 2005 Mulally told Australian Aviation that the “737 replacement” could be more than one fuselage size. “We could do three different fuselages. Five‑abreast, six‑abreast . . . we could even do a twin‑aisle,” he said at the time.

And that modular concept has been examined in detail by Boeing. In 1997, after the merger with Boeing, Douglas engineers produced a “Modular Aircraft” study. The paper, authored by John Allen, called for two fuselage cross-sections, three fuselage lengths and different modular wings for each cross-section, which would result in “six different low-cost aircraft. ” With clever shaping, the internal sidewall structure was common to both fuselages with only fuselage caps unique.

The main pitch was that Boeing could develop a family of related aircraft in a much shorter period of time for substantially lower non-recurring investment and with substantially lower recurring costs.

The idea surfaced again as one of two patents filed by Boeing under the heading “Twin-Aisle Small Airplane,” with Mithra Sankrithi, a manager in Commercial Airplanes’ product development, configuration and engineering analysis group, named as the inventor. The patents were submitted on October 2 2001 and approved in 2003 and 2004. One cabin sports a 2-3-2 configuration and more width than height. In the patent applications, Sankrithi claims the new configuration could deliver “the comfort typically reserved for larger aircraft” while at the same time minimising drag, weight penalties, fuel burn and “economic penalties”.

This was further developed by Sankrithi and a fellow engineer, Kevin Retz, with a patent lodged in 2009 for a composite fuselage design to accommodate a seven-abreast 2-3-2 twin-aisle configuration optimised for the rapid loading of both passengers and cargo.

According to FlightGlobal at the time, the twin-aisle fuselage cross-sectional shape had similar seat economics to those of the corresponding single-aisle fuselage cross-section.

Giving more credibility to the composite patent as a possible replacement for the 757 and 737 in August 2010, then Boeing Commercial Airplanes CEO Jim Albaugh told the Puget Sound Business Journal that the company had made significant advancements in optimising a composite fuselage for a smaller aircraft.

Albaugh also said that Boeing had learnt a great deal about composites for smaller aircraft such as the 737 replacement. “If you’d asked me six months ago, I would have said aluminium” for the 737 successor.

Albaugh added that Boeing had “limited our thinking tofirst-generation composites,” but “as we look at things we can do with second- or third-generation composites, maybe we were a little ahead of ourselves saying it doesn’t scale down as well… Clearly, second- or third-generation composites would lend themselves to more efficiency. ”

Where next?

According to an Ascend report, the response from Boeing and Airbus to fill this market segment will be “very different” to the outof- production 757.

It notes that Air Lease Corporation’s Steven Udvar-Hazy has been very vocal in calling for such an aircraft, and ALC has placed a launch order for the new Airbus A321LR – which is the closest current or new type that fits the bill in terms of seats and range capability.

ALC has 109 A320neo aircraft on order including 30 A321LRs.

That model has a 97-tonne maximum takeoff weight (MTOW) and Airbus COO customers John Leahy claims that the aircraft will burn up to 30 per cent less fuel than a 757.

First deliveries of the A321LR are set down for 2019 and the aircraft will have a third auxiliary centre fuel tank and will fly 500nm farther than the A321ceo.

Airbus says that in a standard cabin 206 passenger layout (16/190) the LR will have a 4,000nm range which tops the winglet-equipped 757’s 3,850nm. The A321 is certified for 240 passengers.

Ascend warns that “developing an all-new 220-240 seater would likely cost as much as a larger widebody program. ”The reference point it says in terms of cost per seat will be the A321neo, and single-aisle aircraft have an advantage from the start in terms of operating costs due to their lighter structure.

“In fact the current A321 and 737-900 match the cash operating cost (COC) per seat of the much larger 787 in comparable dual-class layouts,” says Ascend.

The Ascend reports notes that the “costs of developing a new program do not necessarily scale down with a smaller aircraft, so an all-new 220-240 seater would likely cost almost as much as a larger widebody program. ” It notes that “therefore the size of the potential market becomes a key factor in deciding whether to proceed with a new launch. For example, if only 1,000 aircraft were sold, a $20 billion investment needs $20 million per aircraft extra on the price just to pay back the development costs, compared to an A321 full-life base value (FLBV) of around $54m”.

Thus it argues that an all-new aircraft would require a market of 3,000-4,000 units in order to look attractive.

However, if the 757 replacement was designed from the outset as the ultimate stretch of a baseline 737 replacement aircraft, then the equation changes dramatically, say Boeing insiders.

Ascend contends that “it is clear that the market gap will look different from the perspective of Airbus or Boeing. However, the size and range capability conclusions are probably similar. This means the aircraft is actually close to the original 767-200 (non-ER) or A310-300. Presumably a manufacturer would seek to offer a family of aircraft, implying a stretch aircraft would be similar in capability to the 767-300 or A300-600”. However, one could argue that the 787 and A330neo are pitched at that very market.

Boeing sources tell Australian Aviation while everything is on the table and fluid the “twin-aisle 757 replacement” being the (stretched) basis for the 737 replacement is “intriguing,” while another couched it as “fascinating”.

The Ascend report also looks at the route networks at which the 757 replacement would be pitched.

It notes that although overall growth has been unspectacular, in the 3,000 to 5,000nm range band of the 757 replacement, it is nonetheless “important to several major markets and contains the core networks of some of the fastest growing carriers. ” It adds that the range segment “covers most of the transatlantic market, routes from Asia to Australasia, Southeast Asia to Northeast Asia, and routes from the three Gulf hubs to much of Europe and Asia. Turkish Airlines and Aeroflot have both seen huge growth in this range band. This means that this range bracket is key to five of the fastest growing large network airlines. ” Ascend points out that while it “might be difficult to imagine airlines such as Emirates moving away from large aircraft, or a 240-seat aircraft replacing 777s and A380s on London to Los Angeles, there are many city pairs that offer opportunities to increase frequency, plus numerous new pairings that could be flown. ” It adds that “todaythe 787 or A330-200 are the obvious types to launch new routes above 3,000nm, but the trip costs are around 50 per cent higher than a 737-900 or A321. ”

Back to the future

In yet another touch of irony Ascend believes that US giant Delta Airlines, which wanted the twin-aisle DC‑11 in 1981 and not the 757, could be the key battleground in the 757 replacement saga.

The airline is the largest operator of the 757 with 154 in its fleet and is a major customer for both the 180-seat two-class Boeing 737-900ER (140 in service or on order) and the two‑class 192-seat Airbus A321ceo (45 on order). All told the airline has 652 single-aisle aircraft excluding the 717s that fall into the 737/757 replacement market segment.

If the MDC 1980 DC-11 study was right and a twin-aisle only incurs a penalty of one passenger then Boeing – and Airbus – have an opportunity to redefine travel by introducing a twin-aisle to the 150-260 seat market.

Carlson’s statement in 1986 that “nobody wants to sit in the middle seat” is truer today and the rise of premium economy in its various forms is clear evidence that more and more passengers are prepared to pay extra for comfort.

It would seem inconceivable that the industry, with all the latest proven composite, aerodynamic and engine technologies in its arsenal cannot produce a twin-aisle that has compelling economics.

Passengers deserve it!