The Boeing 767 and the Birth of ETOPS

Federal Aviation Regulation (FAR) 121.161 states "Unless authorized by the administrator, based on the character of the terrain, the kind of operation, or the performance of the airplane to be used, no certificate holder may operate two-engine airplanes over a route that contains a point farther than 1 hour flying time (in still air at normal cruising speed with one engine inoperative) from an adequate airport." The rule was written in the days of the propliner when piston engines didn't have the reliability of modern jet turbines. When the Boeing 767-200ER entered service, it was the first commercial twin-jet capable of crossing the oceans*- when Boeing's director of engineering, Dick Taylor, first approached FAA administrator Lyn Helms in 1980, Helms responded "It'll be a cold day in hell before I let twins fly long haul, overwater routes." Helms even felt that the 60-minute rule was too generous. Despite his opposition, though, in 1982, the FAA began technical discussions with aircraft manufacturers, airlines and ICAO (they had formed a study group of their own in 1982) on the possibility of extended twin-engine overwater flights. At an ICAO meeting in Montreal that December, the FAA asked airline operators of twin jet aircraft to compile a database of inflight events and engine shut downs. Since long range commercial twins were relatively new to the market, the FAA needed a database to draw upon in figuring out the regulatory details of what would become ETOPS flying. After the Air Canada Flight 143 incident (the "Gimli Glider) where fuel starvation resulted in a skillful emergency landing on an old Canadian military air strip, some thought it a set back for what Dick Taylor had been pushing for with the Boeing 767. However, in a speech to the Royal Aeronautical Society in London in late 1983, he argued that fuel starvation would have shut down all the engines regardless of whether you have two, three, or four engines. 

N767BA, the Boeing 767 prototype
(Seattle Municipal Archives via Wikipedia)

In 1980 three- and four-engined aircraft handled all the long range routes, particularly those that were overwater. There was a joke that stated "The reason I fly four-engined aircraft across the ocean is because there are no five-engined aircraft." But modern technology and computerized systems brought to the Boeing 767 a level of redundancy, safety, and efficiency not seen in any prior commercial aircraft. And it wasn't just the reliability of the engines, the various systems of the 767 facilitated the development of ETOPS- Extended-range Twin-engine Operational Performance Standards- the ability of a twin engine jetliner to exceed the old 60-minute rule.

*I should point out at this point that before the 767, some Airbus A300 operators were flying overwater routes beyond the FAA's 60-minute rule under ICAO regulations, but that's beyond the scope of this article and I'll be touching upon the A300 in a future article on ETOPS history. 

For two years Boeing collected reams of data on the first 767 operations, compiling information on every shutdown and failure of any system including the engines in the first two years of commercial airline services. This was supplemented by the FAA/ICAO database that was started in 1982. In April 1984 El Al Israel Airlines became the first airline to operate the 767 on trans-Atlantic services between Montreal and Tel Aviv, but the aircraft's routing complied with the 60-minute rule. Not long after, El Al, Air Canada, and Trans World Airlines (TWA) received exemptions to operate no more than 75 minutes from a suitable diversion airport. This would open up some trans-Atlantic routes and Caribbean routes to the 767. In fact, Air Canada was the first to crack the 60-minute barrier having earned its 75-minute exemption in late 1983. By this point Lyn Helms was no longer the FAA Administrator, the post now assumed by Donald Engen who was more open minded to extended twin overwater flights. (Engen would later become the head of the National Air & Space Museum) Interestingly and perhaps not surprisingly, one of the biggest opponents of ETOPS at the time was McDonnell Douglas, who saw the future of the DC-10 line threatened by the 767. 

In June 1984 Boeing showcased the new 767-200ER's long legs with a 7,500 mile delivery flight from Washington Dulles to Addis Adaba, Ethiopia to bring the 767 to Ethiopian Airlines. The flight required a special one-time FAA waiver to take place. In October 1984 Air Canada took delivery of the first ETOPS-qualified 767-200ER which was permitted to go 75 minutes from a suitable diversion airport. The International Civil Aviation Organization (ICAO), the International Federation of Air Line Pilots Association, the US-based pilots' union Air Line Pilots Association (ALPA) and the FAA made several recommendations to Boeing that resulted in the 767-200ER having a fourth electrical generator independently powered by a hydraulic motor, additional fire suppression features and equipment for cooling of the CRT displays in the cockpit.

By 1985 Dick Taylor at Boeing was lobbying the FAA hard for extension of the 75-minute rule to 120 minutes which would open up a large number of trans-Atlantic routes to the 767. Already several airlines led by TWA had petitioned the FAA for an ETOPS extension to 120 minutes but before the FAA would grant the extension, Boeing had to show "statistical maturity" by equipping a number of 767s with special data gathering equipment to show unparalleled standards of inflight reliability and the Pratt & Whitney JT9D engines had to log 250,000 consecutive flight hours on passenger flights with a very low rate of shutdown.

Trans World Airlines made the first 120-minute ETOPS flight in 1985
(Jon Proctor Collection via Wikipedia)

On 1 February 1985, TWA Flight 810 departed Boston for Paris on the first revenue passenger flight in history under the 120-minute ETOPS rule. The new ETOPS rule shortened the flight distance and it would replace a Lockheed L-1011 Tristar that normally served the route. Before Flight 810 departed, sixteen TWA pilots went through specialized ETOPS training on international requirements, intensive time in a simulator and landing procedures for the airport at Sondrestromfjord in Greenland, the designated 120-minute diversion airport. Eleven observers from the FAA were aboard TWA 810 and the fuel burn was found to be 7,000 lbs an hour less than that of the L-1011 Tristar on the same route. TWA was so convinced of the efficiency of the 767 with the 120-minute ETOPS rule that it spent $2.6 million per aircraft retrofitting all of its 767-200s for 120-minute ETOPS compliance.

But Boeing and Dick Taylor didn't stop there. The existing 120-minute ETOPS rule wasn't enough to get the 767 to Hawaii from California. But Boeing continued to compile failure and shutdown data on the 767 on the trans-Atlantic route to prove the the FAA that it was possible to safely operate the 767 to Hawaii from the US mainland. In 1989, the FAA approved the ETOPS extension to 180 minutes which opened up Hawaii to the 767, as the halfway point between Hawaii and the US mainland is approximately 150 minutes' flying time. But to gain the 180-minute extension, a particular aircraft and engine combination had to show 12 consecutive months of 120-minute ETOPS flights and meet stringent engine failure rates. The first 180-minutes ETOPS flights were made by American Airlines on the DFW-Honolulu routing starting in 1989. By 1993 the entire 767 family, both the -200 and the -300, as well as the possible engine options of GE, Pratt & Whitney, and Rolls-Royce, gained full 180-minute ETOPS extensions.

The first commercial 180-minute ETOPS flights were made by American 767-300ERs DFW-HNL
(Aero Icarus Collection via Wikipedia)

By 1991 the number of passengers crossing the Atlantic on 767s exceeded the number of passengers crossing on three- and four-engined aircraft for the first time in history. By 2000, over 50% of all trans-Atlantic crossings were being made by the 767 family of aircraft. By that time, all brand new 767s rolling out at Boeing's factory in Everett were certified for 180 minutes ETOPS extensions.

It will be the legacy of the Boeing 767 to show that any place in the world could be crossed safely and efficiently with only two engines and it set the stage for the arrival of the Boeing 777 and Airbus A330 family of aircraft that routinely fly routes today that were once the exclusive domain of multi-engined aircraft like the Boeing 747, A340, DC-10/MD-11 and L-1011 Tristar.

Source: Boeing 757 and 767 (Crowood Aviation Series) by Thomas Becher. The Crowood Press, 1999, p145-155.

Birth of the Airbus Family: The A310

The Airbus A310 prototype takes flight on 3 April 1982.

In the days following the start of the 1973 Yom Kippur War in Middle East in October that year, the oil producing nations of the Middle East responded to American materiel support of Israel with an oil embargo that sparked a worldwide economic crisis as the price of oil abruptly shot upwards from $3/barrel to over $12/barrel in a short period of time. As a result, the airline industry worldwide embraced fuel efficiency as the new driver for future aircraft designs. While there were high-bypass ratio turbofans that powered the new widebody designs that were entering service (Boeing 747, Douglas DC-10, and Lockheed L-1011 Tristar), turbojets and low-bypass ratio turbofans were still commonplace in the short to medium-haul fleets worldwide. Many airlines indicated to the major manufacturers that there was a market need for a fuel-efficient aircraft in the 150-200 seat range over short to medium haul ranges. Of the big three manufacturers in the United States who dominated the world commercial airliner market, Boeing's plans were the most ambitious with the launch of not just one aircraft, but two aircraft with a common cockpit with the Boeing 757 and 767. It was in many ways the biggest gamble Boeing had ever undertaken, bigger than building the Dash 80 demonstrator that led to the 707 and even bigger than the launch of the 747 ten years earlier. News of Boeing's plans put pressure on Airbus Industrie to respond as all it had produced by that point was the A300. While there were a range of A300 variants with varying engines, payload and fuel capacities, they were all still essentially the same aircraft and hardly a family of aircraft. Two of the primary founders of Airbus and their heads, Roger Béteille (technical director) and Henri Ziegler (general manager), strongly believed that Airbus needed to emulate Boeing's strategy of building a whole family of different aircraft for different markets if the whole enterprise was to have a future beyond the A300. Boeing's idea for commonality with the 757 and 767 designs resonated with the Airbus team who was commonality among varied designs as a way of proving value to the airline customers, not to mention it would be a strong incentive for an Airbus customer to stay loyal to Airbus in the future.

Part of the problem Béteille and Ziegler faced was that most of the Airbus consortium partners saw the A300 as the end result of cooperation instead of the starting point for future cooperation. A lot of that was driven by the atmosphere of fiscal austerity of the 1970s in the wake of the 1973 oil crisis- Airbus' partner nations were hesitant of putting up more money into the venture, particularly when Airbus was still a bit player on the world market despite the success of the A300. In 1978, for example, Airbus delivered 15 aircraft, all of them A300s. That same year Boeing delivered 203 aircraft across three product lines- the 727, 737, and 747. In fact, it wouldn't be until 2003 that Airbus would deliver more aircraft in a single year than Boeing. When Boeing launched the 757 and 767 programs, they were also capitalizing on market vulnerabilities experienced by McDonnell Douglas and Lockheed in the wake of their trijet programs- Airbus wasn't really on Boeing's radar screen at the time. Despite the market effects on McDonnell Douglas and Lockheed, they were still delivering aircraft as well which were entering service on top of Boeing's numbers. You can imagine what a tall order it was for Béteille and Ziegler to convince the Airbus consortium partners that there was value and potential for the long haul beyond the A300 at a time when they were only building less than 5% of the world's commercial jetliners. It wasn't until mid-1975 that the board of Airbus Industrie endorsed the plan for a family of aircraft- and that endorsement is a testament to the persuasive powers of Roger Béteille and Henri Ziegler. In his book Close to the Sun: How Airbus Challenged America's Dominance of the Skies, author Stephen Aris calls that 1975 decision as the most critical decision in Airbus' history. If Airbus failed, then it was only one aircraft, the A300, that failed. But if they became successful, then that one aircraft wouldn't be enough. The leadership of Airbus Industrie by that point had proven themselves remarkably adept in getting the A300 into production and to market while balancing the interests of the partner nations in the consortium. 

Winning a Swissair order was a strategic priority for Airbus

With the backing of the consortium to expand the Airbus product line beyond the A300, the next task at hand was to determine the configuration of the new addition. The first iteration dated back to the oil crisis of 1973 when A300 sales were near dormant (only four A300s were delivered in 1974). In response to what was seen as an evolving market for something smaller than the A300, what was designated the B10 was a minimum-change variant of the A300 that had a shorter fuselage but the same wing and empennage as the larger aircraft. However, the B10 proposal created a significant amount of discord at all levels of Airbus as the consortium partners argued whether it was needed or not. Lufthansa in particular was keen for a smaller A300 derivative and this had gotten the support of Swissair. In those days, Swissair was one of those flagship customers every commercial airframe builder wanted as a customer. They were a tough customer known to be one of the most difficult airlines to negotiate with- but a Swissair order was badge of prestige for any commercial aircraft design and with Swissair now allying with Lufthansa on interest for a smaller A300 derivative, winning Swissair as a launch customer soon became one of Airbus' primary strategic goals. 

By the time the two airlines were briefed on the B10 proposal, Boeing was well on its way to launching the 757/767 program and compared to those aircraft, the B10 had no fans with either Lufthansa or Swissair. Their objections of the proposal stemmed from two points- the first one was that by the time of proposed service entry, the B10 design would be based on technology and a design that was at least a decade old and more importantly, it had a worse payload fraction than the A300. The payload fraction is one way of measuring an aircraft's efficiency- how much payload can it carry compared to its weight. Since the B10 design had a shorter fuselage married to the A300's wings, it had less passengers (therefore less revenue) to offset the costs of carrying a heavier wing structure. This is one of the reasons why shrinks of commercial airframes tend to not do well in the market- like the A318, 737-500, or 747SP, for example. If the B10 proposal was ever going to get off the drawing board, it needed a lighter wing and whole host of improvements over the A300 to win over the airlines who were being offered the latest in technology with the 757/767. In an unusual twist of history, the prospect of trans-Atlantic cooperation offered an potential answer to Airbus' dilemma. Why not combine Airbus' growing widebody fuselage expertise with the technology and industrial muscle of the United States? The first feelers on such an idea came from McDonnell Douglas in the spring of 1975 for a joint venture for a 200-seat design called the DC-X-200. McDonnell Douglas had long been considering a twin-engine version of the DC-10 and the DC-X-200 was the latest iteration along those lines. However, once discussions moved beyond engineering to management, the talks quickly collapsed. That summer another offer came from Boeing who thought there would be some synergies with the B10 proposal and the 767 program. Whether Boeing was serious or just trying to distract Airbus is still a source of debate to this day, but the proposal would have consisted of the A300-based fuselage and 767 wings and empennage. At the end of the day, however, Airbus lost interest as it became apparent that they would end up a Boeing subcontractor in the joint venture. 

Lufthansa was an early A300 customer who drove the design of the A310.

Still keen to win over Lufthansa and Swissair, Airbus decided to follow as Boeing had done with the 757/767 and go with a two-crew flight deck and CRT displays. That would prove to be a relatively easy step to take but it still provoked the ire of the pilots' unions of several European carriers. The need for a new wing, however proved to continue to be problematic. I had posted previously that it had taken the personal intervention of a German politician, Franz Josef Strauss, to fund the A300's wing development and construction by Hawker Siddeley as a result of the British government's withdrawal from the Airbus consortium. Hawker was still the center of the most advanced wing design work in Europe and was in the process of merging with several other entities to form British Aerospace (BAe). With British Aerospace being majority owned by the government, there was considerable anguish at Airbus as to whether or not BAe would participate in the B10 project given the British pull out of the Airbus consortium in 1969.  When Hawker elected to remain an Airbus participant despite the pullout, they had absorbed a portion of the costs of wing development. Now that Hawker was part of BAe, no one was sure that the new entity was willing to front such costs again for the B10 project. Airbus decided at that point to turn to its partners for a wing design- Aerospatiale and VFW-Fokker each submitted wing designs and Roger Béteille was sure that whoever was chosen, it would be the end of Airbus as the other partner would feel jilted. As it turned out, neither was chosen- the German design was aerodynamically superior but the French design was structurally superior. A joint-wing design center was established to combine their efforts and word of this got back to BAe quite quickly that their replacement was in the works. 

The exact political machinations in the UK that resulted will be the subject of a future blog article, but they were contentious with pro-Airbus factions in the British government and those who favored a joint-venture with Boeing on the 757. At the end of the day, however, BAe did end up designing and fabricating the wing which was not only lighter, but was of supercritical section which made it not only more aerodynamically efficient but also offset the smaller size with a deeper airfoil section which offered more fuel capacity. Getting the wing also meant that the British eventually rejoined the Airbus consortium with a 20% share. On 9 June 1978, Lufthansa and Swissair issued a joint specification for the new aircraft and within a month announced intentions of placing orders for what was launched as the Airbus A310. On 15 March 1979, Swissair announced its launch order for 10 aircraft and 10 options with plans to use the A310 as a replacement for its legacy DC-9 fleet on its major intra-European routes. Lufthansa quickly followed with an order for 10 aircraft and soon after Air France and Iberia also placed orders, assuring the production and success of the A310. When the A310 prototype flew, it would later wear Swissair's colors on the right side and Lufthansa's colors on the left side. Many of the advances of the A310 were later incorporated into an upgrade of the A300, the A300-600. 

Further reading: 

How American Airlines Shaped the A300

How Rolls Royce Scuttled British Participation in Airbus

The Early Days of Airbus Industrie and How the A300 Got Its Name

Franz Josef Strauss: The Bavarian Politician Who Saved Airbus
How a Lot of Airbus Jets Were Born on Boeing Wings

Related reading:

American Airlines Picks the DC-10 (American's pick of the DC-10 is intertwined with the early history of Airbus)

Source: Close to the Sun: How Airbus Challenged America's Domination of the Skies by Stephen Aris. Agate Books, 2002, pp 90-95. Photos: Wikipedia

During the development of the Boeing 757, once it was decided that both the 757 and 767 flight decks were to be common, the original design for the 757's cockpit that was based on the 727 now faced the challenge of having to fit the widebody cockpit of the 767 onto the single-aisle design of the 757. In a rare move for Boeing, the design of the 757's nose was reconfigured after program launch in an effort to achieve a common rating for both aircraft.

Using the same forward windshield, related structures and cab geometry as the 767, the design was then altered to suit the narrower fuselage of the Boeing 757 with the goal of having the same visual and ergonomic geometry for the flight crew as that of the larger 767. The 757's nose section curves upward more dramatically than past Boeing jets as the point of nose is actually below the fuselage centerline with the flight deck floor a step down from the main deck.

The result was a cockpit with more visibility than past Boeing designs and aerodynamic noise also improved, with a 6 dB drop over the aerodynamic noise of the 727. The wider cockpit improved storage space with more room as well as improved air conditioning circulation patterns and the by providing a wider space at the front of the aircraft, there was more space for the forward lavatory and galley.

The extensive changes to the 757's nose and cockpit were all driven by the need for a common type rating for both aircraft and as the 767's cockpit had been designed first, it was adopted for the 757 with modifications. But with an identical windshield and instrument panel, much of the associated structure was also nearly identical in many ways.

Source: Boeing 757 and 767 (Crowood Aviation Series) by Thomas Becher. The Crowood Press, 1999, p33-35.