Narrow Widebody - Boeing 767
It is a pleasure to again host guest commentator and commercial pilot Chris Cook, who offers his insight into the historical market of the 767 alongside its competition - the Airbus A300 and A310.
The ultimate “narrow” wide-body airplane.
Boeing officially launched the 767 family on the 14th July 1978 with an order from United Airlines for up to 30 767-200s. At the time, Boeing said that the 767 launch “climaxed several years of unprecedented airplane development activity. Never before in Boeing’s history has a new airplane been so thoroughly studied, analyzed, and wind-tunnel tested prior to official go-ahead.”
Boeing was clearly “bullish” regarding the size of the 767 market, and predicted the market would require between 1,000 and 1,500 airplanes over the next 20-years at the time of launch. However, markets never stand still, and by the end of July 1978, Airbus had hit back hard with the launch of their new high-tech twin-engine wide-body airplane, the A310-200. The race was on between the two competing airframe manufacturers to secure market dominance in the 200-seat commercial jetliner market.
Image courtesy of Boeing
Airbus pointed out that the A310 had a much wider fuselage than the 767-200, and therefore Airbus claimed that the A310 would offer better passenger comfort due to wider seats and wider aisles, whilst also offering greater seating flexibility options. The A310 has a maximum cabin width of 5.28m, whilst the 767’s is some 58cm less at 4.7m. Further, the A310’s wide-fuselage, 5.64m allowed for two industry standard LD-3s to be loaded side-by-side in the cargo bay; something the 767, with a fuselage width of 5.03m was unable to achieve. Boeing knew that the 767’s narrower fuselage was a major drawback in terms of it’s inability to carry two LD-3’s side-by-side, but remained firm that it offered better qualities than the A310 in two key areas; ironically both in volumetric cargo space and passenger cabin flexibility.
Was Boeing bluffing? No.
Boeing gambled that a new specially designed container for the 767’s lower-lobe cargo holds would be widely adopted. Boeing initially revealed the new container as an LD-3A, but quickly changed it to LD-67 as the former sounded too much like a compromise. The LD-67 was eventually renamed the LD-2 of today. Despite having to adapt to a new cargo container for the lower hold in order to efficiently full to volume available, Boeing hit back at Airbus and claimed that the 767 offered up to 30% more cargo volume than the A310.
In terms of passenger cabin comfort and flexibility, Boeing claimed that the 767’s cabin width was ideally suited for the passenger market.
“The 767 body was designed to cater to the people market, rather than the freighter market,” said Boeing engineer Jack Steiner at the time, pointing to the 767’s unique 7-abreast seating cross-section arrangement in economy.
This new cross-section philosophy on the 767 meant that the airplane had to be more than 80% full before the middle-row centre seats had to be occupied. These seats are famous for being heavily un-popular with passengers due to the need to “push-past” passengers to get to and from the centre seat. Therefore, the 767 offered the preferred cabin arrangement over the A310 according to Boeing.
Boeing knew that the 767 would evolve into a family of derivatives as the airplane indeed offered sheer design flexibility, and soon after the first -200s started rolling off the production line, the ground work was already in place for the launch of the equally popular -200ER versions. All -200s built from line number 86 onwards, regardless if they were -200ER order variants, incorporated structural provisions for the higher weight and extra fuel tanks that the -200ER required. However, the -200ER of today is an entirely different animal than the -200ERs of the early 1980s.
Back in the early 1980s, competition intensified with the A310 with Airbus moving ahead with the longer range and heavier A310-300 variant, prompting Boeing to beef up the -200ERs in order to provide more range and payload. This ultimately led to the 767 becoming the pioneer of ETOPS and ushered in the market phenomenon known as fragmentation. The 767 arguably became the first point-to-point, highly-efficient twin-engine, wide-body airplane.
The first -200ER variants were launched by ETOPS pioneers, Air Canada and El Al, and offered a maximum take-off weight of 151, 927kg (335,000Ibs) or some 24,923kg (55,000Ibs) greater than the basic -200s. However, it wasn’t until December 1982 that the real performance and weight increase for the -200ER came when Ethiopian Airlines ordered two 156,463kg (345,000Ib) maximum take-off weight -200ERs. These -200ERs offered far greater fuel capacity and range, with the additional fuel being carried in both the centre wing section as well as in two or three cargo bays converted into fuel tanks. However, the -200ERs range and weight was in for yet another growth spurt, and by late 1986, Boeing offered the 175,510kg (378,000Ib) maximum take-off weight version. By the 21st Century, the -200ER received its final boost to its range with the airplane featuring the 179,160kg (395,000Ib) maximum take-off weight.
Image courtesy of Airbus
Clearly, the 767 offered huge growth potential from the original -200 design, and it was mostly thanks to the extraordinary new wing the 767 featured. The Airbus A310 too featured an all-new wing design over the sister A300; an aft-loaded, super-critical wing design similar to the 767’s. The 767 features a 31.5 degrees wing sweep at mean aerodynamic chord (MAC), as well as relatively high aspect ratio of 7.98. The A310 features a wing sweep of 28 degrees at the MAC, whilst its aspect ratio is higher than that of the 767 at 8.8. The key in the 767’s greater growth ability over the A310 lay in the 767’s greater wing area of 3,050 square feet compared to the A310’s 2,360 square feet, which also allowed the 767 to have a higher initial cruise altitude over the A310’s. The 767s wing design also provided one of the best elliptical spanwise distributions of lift ever achieved on a Boeing airplane of that time. Elliptical lift characteristics on a wing result in an even and equal distribution of lift across the aerofoil and also results in a reduction of induced drag, hence the wing is incredibly efficient.
When Airbus ended production of the A310, they had sold 255 examples. It was certainly a very successful production run, and when combined with the total sales of the A300 family variants, Airbus had sold 816 A300/A310s by the end of production in 2007. The Boeing 767 family naturally grew into a variety of variants, with the -200/-200ER securing 249 orders, or 6 shy of the A310 order book. However, the 767 remains in production today, albeit with the main interest generated from the unique market position 767-300ER; both passenger and freighter model. Total 767s ordered up until July 2009 stood at 1036.
Christopher Cook
Commercial Pilot,
Johannesburg, South Africa.
26 comments December 1st, 2009
