Back to the future

It will also be the ultimate “sporty game” of nerves and resources. And complicating that game are massive order books requiring unprecedented production rates of around 40 aircraft for both the A320 and 737.

The decision facing Boeing for the 737 replacement is the most critical the company has taken since the 747 and in a touch of irony there are many in the company that didn’t want to launch the 737 as the DC-9 and BAC1-11 had such a strong market foothold with then US market giants TWA, Delta, Eastern and American Airlines committed.

Only United was yet to make a decision and went with the 737 in April 1965 because it had a wider fuselage than the competitors and the width of the fuselage is also the biggest dilemma facing Boeing today.

In fact the launch customer was Lufthansa, which committed to the 737 in February of that year after Boeing, which had been guaranteed United’s order if it stretched the baseline -100, assured the German airline that the program would not be cancelled.

The 737-100 which first flew in 1967 could carry 99 passengers over 2,775km with a payload capability of 11,818kg. By comparison the most recent model in widespread service, the 737–800, can carry 189 passengers 6,105km and a payload of up to 20,454kg.

Continuous improvement

One of the major keys to the success of the 737 family has been Boeing’s relentless focus on improvement packages for the aircraft from redesigned and enlarged wings to more aerodynamic tear drop lighting on the fuselage.

And more recently Boeing gave the interior of the aircraft a major “787” styled make-over to counter the slightly wider A320 cabin.

The Boeing Sky Interior offers passengers redesigned overhead baggage bins that give more headroom and hold more carry-on baggage. Eight shades of LED lighting are available which enhance a sense of calm and spaciousness.

The interior also features sculpted sidewalls that create more appealing windows, less confusing passenger light switch panels and cabin lights with various levels of luminosity.

The first 737NG equipped with the Boeing Sky Interior was delivered to flydubai on October 27 last year, followed by delivery to Malaysia Airlines. Overall, 50 airlines, including Qantas and Virgin Blue and leasing companies have ordered 1,386 737s with the Boeing Sky Interior.

From next month Boeing will deliver the first aircarft which sports a new aerodynamic and engine – CFM56-7B – package that will cut another 2 per cent off the aircraft’s fuel burn.
While 2 per cent may not seem a lot it translates into a saving of US$120,000 a year savings in fuel per aircraft at US$2.58 a gallon for fuel on a 500 nautical mile trip.

“Environmentally, that’s 470 tons less carbon emitted per aircraft annually and with a carbon tax of $25 a ton that’s $11,700 a year at $25 a ton per airplane,” says Jamie Jewell, director of strategic communications for CFM International.

Reductions to drag on the airframe are achieved through redesigned wheel fairings, louvered exhaust duct doors, wing surfaces, and the anti-collision light.

Airframe modifications, notably a shorter nozzle, account for half the improvement; engine improvements contribute the other half. CFM is using advanced computer codes and three-dimensional design techniques to improve airfoils in the high- and low-pressure turbines to improve engine fuel efficiency. In addition, the company is improving engine durability and reducing parts count to achieve lower maintenance costs.

And that durability is translating into a significant reduction in IFSD rates and higher dispatch reliability. According to GE Director Boeing Programs Kris Shepherd ‘the IFSD rate for the latest models of CFM56 is 0.002 or 2 shutdowns per 1 million hours, which means 14 out of 15 pilots commanding CFM56-powered aircraft will never experience an in-flight shut down.”

Dispatch reliability is also at an all time high. “We have a 99.8 per cent dispatch reliability,” says Beverly Wyse, VP and GM 737 Program. “While we are proud of the progress we have made on this airplane, we are by no means done.”

Even with improvements, Boeing and CFM engineers believe there are more to be found says John Hamilton, chief project engineer on the 737.

“The new performance improvement package to the airframe and engines may get more but we are telling customers it is 2 percent,” improvement over the current 737, Hamilton told Australian Aviation.

CFM also believes it may have under-promised on fuel gains. “What we’ve seen in the test cell on our engines is actually better than the 1 percent committed to Boeing,” Jewell said. “But for now we are sticking with 1 percent until we see how it performs on the aircraft.”

On top of the fuel savings, the engine improvements will also bring up to 4 percent lower maintenance costs with a design that not only includes fewer airfoils but also more durable parts. The higher thrust engines will also benefit from great Exhaust Gas Temperature (EGT) margin, which will contribute to longer time on wing.

Overall, 737NG series has attained a 5 percent fuel consumption reduction since the first one went into service in 1998 and the additional 2 per cent from next month will lift that to 7 per cent over 12 years, Hamilton said.

The first aircraft, a -800, with the improvement package will be delivered to Continental Airlines.

One of the biggest fuel saving innovations for the 737 has been the Blended Winglets introduced in 2002 which have reduced fuel burn by between 3.5 and 4 per cent.

According to Hamilton Boeing is now revisiting old ideas to the light of new technologies. “Lighter floorboards, for example, might now be an option worth restudying.”

But Hamilton says airlines are not telling the company to re-engine the 737. “We are not getting a strong response to re-engining. The customer is not telling us to go for it. Considerations go beyond fuel costs alone. Customers want fuel consumption improvement but how they get it remains a question; no one wants technical changes that snowball into affecting the 737s operational excellence. You have to balance technology with the inherent reliability of the airplane,” Hamilton said.

Jewell adds perspective to that debate saying that in a CFM survey of lessors and airlines conducted in 2009 the “top concern is reliability.”

Jewel adds that “The aircraft have got to be ready to go or the business model for most low-cost carries does not work.” And possibly not surprisingly maintenance costs and time on wing came in next while fuel consumption was ranked fifth. “So while it is a priority, it is not the only factor airlines are taking into consideration.”

Of course as fuel climbs in price so does its ranking if importance.

Another of the great success stories for the 737 has been the lean manufacturing and slimming down of the supply chaina concept borrowed from Toyota.

From 2000 and 2006, Boeing replaced stationary construction with a line that moves an average of two inches a minute. The Renton factory building was redesigned to facilitate better communication between engineers, administrators and mechanics, while offices were built in the factory so that engineers and other support personnel could be closer to the production line, allowing for quicker resolution of issues and more opportunity for sharing of ideas.

This concept has flowed through to the Everett operations as well.
Lean manufacturing has enabled Boeing to halve the production from 22 days to 11 days.

The 737’s production is currently 38 a month and sold out through 2016 and Boeing is “turning blue-chip customers away” say analysts says Richard Safran from New York based Buckingham Research.

Safran believes that Boeing’s strategy “will likely be to continue to raise 737 production rates in order to clear out the backlog and prepare for the launch of a new airplane. We believe narrow-body demand remains robust and that BA will announce it is raising 737NG production rates to 42 a month.”

Twin or single aisle?

Boeing’s response to the threat of the A320neo has been the subject of intense debate and speculation with many saying that Boeing’s response will be a twin-aisle or include a twin-aisle in a family concept.

Put simply both Airbus and Boeing are in a conundrum of where to draw the line on the baseline for the aircraft’s size and thus to fight to retain market share.

The original 737 concept dates to early 1964 and in its original form the 737 was five across concept but that quickly gave way to a six across 86-seater with a gross weight of 79,000lbs that would use the same fuselage as a 727 and have 40 per cent parts commonality.

By the time it was launched with Lufthansa’s order it had grown to a 100 seater with a gross weight of 85,000lbs.

This lift in performance put the 737 ahead of both the DC-9 and BAC1-11 at the time, although those two aircraft were quickly stretched.

And Boeing had to almost immediately stretch the 737 to win the United Airlines’ order which was for 40 -200s with a gross weight of 97,000lbs and 113 passengers at 34-in seat pitch.

Since then the aircraft has been stretched a number of times to its current ultimate version the -900ER with a maximum takeoff weight of 187,700lbs with an exit limited capacity for 215 passengers at 31-in pitch.

Key to what shape and form the 737 replacement will be is where Boeing optimises the aircraft and many suggest that it will be between 180 and 200 seats with capability up to 250.

Its biggest airline customer Southwest Airlines has recently agreed to order the larger -800 189-seater version of the 737 raising the prospect that the baseline will be in this region.

Boeing Commercial Airplanes President Jim Albaugh has noted that doing nothing is “not an option.”

Boeing’s VP Marketing Randy Tinseth adds some detail to what airlines are looking for and what technologies may be available. “Our customers are looking for 15 to 20% improvement in fuel efficiency, 25% improvement in maintenance costs, enhanced passenger experience and a double digit improvement in operating costs – so the bar is high.” Tinseth adds that Boeing expects gains from the continued advances in aerodynamics, composites and systems and even greater improvements in the engines.

However, according to New York based Bernstein Research the options for Boeing are complicated. Because of the necessity to modify the undercarriage to accommodate the new engines’ wider fans, development costs have been put as high as US$4 billion.

And in a pricing battle with Airbus Bernstein says that the premium both manufacturers want will be “competed away.” The fan diameter for the current CFM56-5B is 68-in, while the Leap-X is 76-in. and the PW 1100G 81-in.

While some argue that a single aisle solution is better because of lower drag the wider 737 wiped the floor with the five-across DC-9/MD80/MD90 family, while the similarly configured BAC1-11 and Caravelle went out of production decades ago.

It is interesting to look back and compare the widths of the single-aisle short haul competitors of the 1960s. The Caravelle has a 118.5 in. interior width, the BAC1-11 124.5-in., the DC-9 122-in. and the 737 139-in.

Whatever Boeing does it must widen the fuselage of the 737 and if a single aisle is chosen then it will undoubtedly be wider than the A320 by at least 6 inches to allow for wider seats to accommodate a larger population.

It can well be argued that the extra “physical width” for passenger seats can traded into a second aisle with the “enhanced spaciousness” compensating for standard width seats with extra shoulder room afforded by the aisles for all passengers except those on the windows, where wider seats could be fitted.
But one issue that requires extra physical space is the amount of room required for passenger’s carry-on baggage. When the 737 was first designed it simply had a hat rack!

The boarding process in the US is quite simply a nightmare with single aisle aircraft of all types unable to cope with the carry-on resulting in tense standoffs as passengers try to cram oversized bags into undersized storage bins.

The long boarding process results in a blowout in turn times savaging the LCC economic model. A twin-aisle with additional centreline bins could solve both problems.

Another dynamic is underfloor cargo with 737s and A320s now performing roles in many markets for which they were never designed – transcontinental trunk routes where the ability to carry and interline LD3s is becoming more critical.

If the 737 replacement is to be able to load LD3s it will be a twin-aisle aircraft by simple virtue of the physical dynamics of needing an underfloor height of 163cm compared to the current 110cm on the 737.

Back to the future

In a rare interview on what a 737 replacement would look like Boeing VP-Advanced 737 Product Development Mike Bair told Flightglobal in March that studies were focused on a twin-aisle solution to the market demands of faster turn times, larger passenger size plus greater carry-on baggage.

Separately, Australian Aviation has learned that Boeing will announce an all-new 737 replacement, to be named the 797, at or before the Paris Air Show commencing June 20. Bair’s comments regarding the replacement being a twin-aisle have not been denied by the company.

The 180-seat twin-aisle concept has a fair amount of history. McDonnell Douglas developed a 180-seat twin-aisle concept in a 2-2-2 configuration from the late 1970s dubbed the ATMR, then the DC-XX and finally the DC-11.

At the time, airlines were extremely interested in the six-across twin-aisle concept, but McDonnell Douglas wanted another airline onboard, and larger progress payments to help cash flow.

Then-Delta Senior VP Robert Oppenlander summed up the situation in an interview with Business Week in December 1980: “They [MDC] wanted to launch a new plane without taking any risk. That ain’t the way it works.”

Balancing that view, John McDonnell, a current Boeing board member, 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 the magazine at the time. As it turned out, Delta ordered 757s, American Airlines followed and the DC-11 project folded.

The DC-11 fuselage had a cross-section that was 22-in. wider than the 727/757, allowing for 17.7-in.-wide seats in doubles with two 18-in. aisles. In an all-economy layout at a 30-in. pitch, it could seat 214.

Using the latest technology at the time, including composite floor beams, control surfaces, nacelles, vertical and horizontal stabilizers and other primary structures, MDC predicted fuel consumption 8 per cent better than the 757 with the same engine application—the JT10D-32 engine rated at 32,000 lb. thrust. The fuel burn advantage was despite the wider fuselage.

Since then the science of aerodynamics and integration has gone ahead in leaps and bounds and using Bombardier’s guarantees for the CSeries with relationship to aerodynamic gains an overall gain of 20 per cent plus could be expected for a twin-aisle over the 757.

Boeing also floated the twin-aisle 180-seat concept in 1987 with its 7J7 and showed a full cabin mockup at that year’s Paris Air Show. It took the wide-body concept further with a 181-in. cabin width that would permit 2-3-2 seating, 17-in.-wide seats and 18-in. aisles in coach. It is this cross-section that insiders at Boeing tell Australian Aviation is the subject of intense focus.

The twin-aisle idea surfaced again in 2001 in 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 Oct. 2, 2001, and approved in 2003 and 2004. One cabin sports a 2-3-2 configuration with Sankrithi claiming the new configuration could deliver “the comfort typically reserved for larger aircraft,” while at the same time minimizing drag, weight penalties, fuel burn and “economic penalties.”

The fuselage cross-section for the 2-3-2 configuration is 200.7 in., fractionally wider than the 767’s 198.03 in., and the design features a swept T-tail.

Interestingly, Sankrithi filed another patent last year with co-engineer Kevin Retz, shown recently by Flightglobal , with the same T-tail twin-aisle under wing engine layout, which is similar to the configuration and layout of another McDonnell Douglas aircraft: The 1981 vintage 150-seat MDF100, which was to be built with Fokker on a 50/50 basis but didn’t get off the drawing board.

In a differing view, Buckingham Research’s Safran said Boeing will launch a new single-aisle transport. “We think that the technology for a new aircraft with a 25 per cent direct operating cost improvement could be available to support service entry in 2017/2018,” he noted in a client report.

He argued that with sustained higher fuel prices likely in the future, there will be demand for a more fuel efficient aircraft than any of the new market entrants, including the A320neo, can offer. Boeing will “need to respond to the threat of share loss posed by new entrants in the market,” the Buckingham report stated, adding that “neither a re-engined 737NG nor A320neo offers operators a sufficient operating cost improvement to justify the price premium.”

However the Safran suggests that Boeing is looking at two strategy options for an all-new narrow-body. The first option is to develop a family of two aircraft—a 125-180 seat aircraft to replace the 717 and 737-600/700/800, and a 180-240 seat, long range aircraft to replace the 757-200/300 and 737-900.

On that theme at the Paris Air Show in 2005 then Boeing Commercial Airplanes President Alan Mulally told Australian Aviation that the 737 replacement could even 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.

In 1997, after the merger with Boeing, Douglas engineers produced a “Modular Aircraft” study. The paper 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. The advent of all-composite aircraft would make this modular concept easier to achieve.

Interesting the most successful aircraft in history the DC-3 was itself a fuselage width stretch from two-across to three.

Wrong choice?

New York-based Bernstein Research believes Airbus has made the “wrong decision” on the A320neo and that “a lower risk evolution of the A320 would have been preferable.”

Bernstein argues that airline will not pay the US$6 million to US$8 million price premium per aircraft over the current A320 which is required to justify the business case.

However Airbus COO Customers John Leahy in a interview with Australian Aviation said that the efficiency improvements of the neo translate into savings of up to “3,600 tonnes of CO2 annually plus a double-digit reduction in NOx emissions, reduced engine noise, lower operating costs and up to 500 nm (950 km) more range or two tonnes more payload.

Leahy adds that “the fuel savings amount to 1.4 million liters a year which is the equivalent of 1,000 family sedans and the CO2 saving is equal to 24,000 mature trees.”

While the A320neo promises significant fuel savings, it will simply be an engine option upgrade, says Leahy. “We are only changing the pylon, engine and nacelle – nothing more. There will be a 95 per cent parts and 98 per cent manufacturing commonality with the A320 family.” Airbus puts the market potential of the A320neo at 4,000 over 15 years with analysts putting development costs between US$1.5 billion and US$2 billion. However Leahy notes that while the timeframe for an all new design is slated for 2025-27 that is not certain.

Leahy’s pitch is that there is no new technology to justify a new design now or even in 12 years. “We are saying the technology doesn’t exist to do a new aircraft before then and possibly not even then. We looked at a clean sheet design last year and the best we could do was a 3 per cent improvement [over the A320neo].”

But Leahy adds a note of caution to that line of thinking. “A western European airline CEO said to me recently that once the public and environmentalists know that we can achieve a 15 per cent fuel saving and we are not doing it because the business case doesn’t stack up we will get hit on the back of the head,” recalled Leahy. “Governments might even say if you don’t do it, we will legislate.”

To the claim that the fuel savings are not enough to justify the investment Leahy adds that there has never been an aircraft re-engine program in the jet era that offered 15 per cent fuel savings that “wasn’t an overwhelming success.”

According to Dallas-based aviation analysts Oliver Wyman, the 737-300 over the 737-200 gave a 5.6 per cent improvement in fuel burn, while the NG over the -300 was better at a 9.5 per cent gain. The 747-400 business case was based on a 9.5 per cent reduction in fuel over the -200 which also gave it Singapore-London range with an economic payload.

While the fuel saving is touted heavily and is critical, a major advantage of the re-engined A320neo will be the noise profile with the likely ability to operate into many curfew airports because of a reduction in the noise footprint of up to 77 per cent.

With more and more airports seeking curfews, this is emerging as a major issue. Approximately, 400 of the world’s 600 major airports have some form of noise abatement procedures, while 200 have curfews — double the number in 1990, according to Boeing. Leahy predicts that the A320neo will be a winner at noise sensitive airports. “There is no doubt it will be a curfew breaker,” he says.

Udvar-Hazy’s views

Air Lease Corp. CEO Steven Udvar-Hazy, whose statements on aircraft programs have long carried significant weight, said Boeing’s 737 replacement solution will likely include a larger aircraft offering for which the twin-aisle concept makes sense.

According to the Seattle Times he told reporters at the International Society of Transport Aircraft Trading conference in Phoenix last month that he believes the upper end of Boeing’s new family will be a 757-size jet with more than 200 seats.

While he does believe a 757-size aircraft will be part of Boeing’s 737 replacement program, he asserted the manufacturer will offer a two-airplane solution that will also include a single-aisle model with a baseline of 150 seats.

Then-Boeing Commercial Airplanes President and CEO Scott Carson told Australian Aviation in 2007that the company was conducting trade studies on two fuselage widths and could offer the market two solutions with common cockpits, wings and engines.
Udvar-Hazy told the Seattle Times that, “based on historical performance and just their DNA,” Boeing will build a new aircraft family that will “address the next 25 to 30 years of airline demands.”

Udvar-Hazy added that the A320neo is a threat to Boeing in the short term and predicted the company would work more incremental improvements into the 737NG.

However on a smaller aircraft than the 150-seat baseline Udvar-Hazy told Flightglobal said that he doubted that Seattle or Hamburg with their labour costs could build a 120 to 130-seater aircraft that could compete with designs coming out of emerging markets. “So can Boeing and Airbus be the low-cost producers at the lower end of this new generation of aircraft and I don’t know the answer to that, but my instincts tell me is that some of these new competitors could ultimately have the lower cost, just like when the Japanese car companies invaded the US in the 70s and 80s.”

Udvar-Hazy is keen on a twin-aisle solution to the upper end of 737 replacement market. “In all of the studies that we have done and in talking to airlines, you can turn a twin-aisle aircraft faster if you have good passenger access. So the whole idea of a short- to medium-haul aircraft is maximizing utilization and if you can get ten minutes a turn and you do six segments a day you can get an hour more flight utilization,” he told Flightglobal’s Mary Kirby.

“Look, at the upper end of that market, once you get above 200 seats. How many of you have flown on a 757 when you’re in row 39F and how long does it take to get off the airplane if they’re loading only through the front. Sometimes it [feels like it] takes longer to get off the airplane then the flight itself. My feeling is that to be a really an effective airplane above 200 seats and a great competitor and have the cargo capacity, which is also an important element in the revenue generation of airplanes, a small twin-aisle has a lot of advantages once you get north of 200 seats,” added Udvar-Hazy.

On Airbus’s decision to launch the re-engined A320neo Udvar-Hazy said the move was forced by insufficient funding to launch an all-new aircraft. He warned that the A380’s ongoing production costs, plus the development of the A350 and the A400M, would tax Airbus’s finances for another five years. “It will not be possible as a practical matter for Airbus to launch a completely new airplane,” he told reporters.

Predictions

Mark Twain said that “the art of prophecy, particularly related to the future, is very difficult” and so it is for Boeing and Airbus in the 737/A320 replacement decisions particularly when overlaid against the volatility of the price and supply of fuel.

But if algae based biofuel takes off into full scale production, price and supply may not be issues in ten years time.

And just to make things interesting Rolls Royce and General Electric continue work on their open rotor concepts that promised fuel savings in the 30 per cent region for the 180-240 seat market.

However both engine designs would have to be tail mounted meaning a totally new aircraft than the ones currently canvassed.

And the manufacturers are not replacing an aircraft that sells at two or four a month – the rate is just over 1 a day!

The reality will be that both the 737 and A320 will remain in production even after the “737 replacement” and “A320 replacement” is delivered as some airlines will just want base price and simplicity.

According to Safran “both Boeing and Airbus appear to be indicating that they expect 737NG and A320 production to continue well into the next decade. Airbus indicates that A320 family production will continue until 2030 and BA has indicated that 737NG production could continue until 2026.”

Safran adds from the ISTAT conference that he believes that Boeing’s strategy is to develop a new 150-240 seat airplane to compete in the 150-seat plus market and continue production of the 737NG to compete in the market below 150 seats”

He added that Boeing for the first time said that “it is doubtful a new, light twin-aisle airplane is the answer.”

Airbus has questioned the wisdom of Boeing launching an all new aircraft to compete with the A320neo saying it will only have 3 per cent improvement in sfc.

However Safran notes that Airbus’ comments omit aerodynamic improvements offered by a new wing, maintenance expense improvements offered by a later generation engine, and a relevant cost comparison as a 3 per cent sfc improvement could justify the new BA airplane if pricing were favourable.
Another perspective came at the launch of the A320neo when Guy Hachey, Bombardier Aerospace president told media that he expected the CSeries to be able to offer “double digit” cost and fuel burn savings compared to the A320neo. Hachey called the Airbus offering “a new engine on an old plane.”

Hachey argues that nearly half of the 20 per cent fuel efficiency that the CSeries promises over competitors is derived from composite structure and advanced technologies, with the balance from the PW1000G. “There is no way that putting a new engine on an old aircraft will give the same level of savings,” Hachey told media.

And Australian Aviation understands that GE and CFM are in fact working on a new engine for the 737 replacement that would be a significant improvement over the LEAP X.

As Boeing mulls its choices it should perhaps look at the transcontinental Australian market where passengers will change their flight to avoid a 737 on a five hour flight.

It should then take a long hard look at US boarding times, the amount of luggage that is carried on and the increasing size of the passengers.

The 737 was originally designed to carry 99 passengers for about 90 minutes. It and the A320 now carry more than double that number up to six hours!

That’s a middle seat too far and begs the question; Will Boeing let the twin-aisle improvement in flying and flying equipment pass it by.