The 757 Story Pt1: From 727-300, to 7N7, to 757

​The Boeing 727-200 Advanced was spectacularly successful during the 1970s but although orders were flooding in Boeing didn’t rest on its laurels and was looking for ways to improve the design. In the end the result wasn’t the initially designed stretched 727-300 but instead an all new jet, the 7N7, that was paired with its big brother the 7X7 to take on McDonnell Douglas and Airbus into the 1980s and 90s.

Boeing Prototype 757-200 N757A NG Models 1:400 Scale Model Airliner

Boeing’s initial ideas to satisfy a requirement from United Airlines was a simple 18ft 4 inch stretch of the existing 727-200 equipped with uprated engines  and new landing gear to make a 727-300. United showed interest, as did Braniff who was looking at purchasing in 1977, but in the end the design wasn’t good enough.

A rare model of the first 727-300 trijet

​It almost made it, in fact United was lined up as the launch customer with a 50 aircraft $600 million order, which got as far as a press release, hastily withdrawn by Boeing after publication, when on August 28, 1975 United announced they wouldn’t be buying the 727-300 after all. At the time United blamed poor economic conditions and a lack of tax incentives but in reality, the 300 simply didn’t offer the saving in fuel efficiency that was needed in a post Yom Kippur world where fuel prices had skyrocketed due to Western support of Israel.

A 727-300 twinjet!

Boeing spent another 5 months trying to make the 727-300 a feasible aircraft but couldn’t create a cheap enough aircraft that retained any value. This failure led instead to Boeing aiming for a new design, which nonetheless would still be based on the 727 but offer a 30% fuel saving. The 7N7 designation was first used in January 1976.

​Boeing targeted Eastern and British Airways as launch customers and Rolls Royce was keen to be involved with Boeing as the engine manufacturer. Boeing was also keen to partner with British Aerospace who would make the wings but disagreements between the two companies over the form of the partnership and price led nowhere despite the involvement of the British Callaghan Labour government. In fact, the negotiations ended with Rolls-Royce going with Boeing and British Aerospace partnering with Airbus to produce wings for the A310. 

​Boeing would have to go it alone making two families of new aircraft (the 727 derived 7N7 and the all new widebody 7X7) and there was some skepticism that Boeing could make two separate airliners at the same time. Initially Boeing was looking at a 164-seat design but Eastern especially was attracted to a larger 178 seat size with lower per seat operating costs. British Airways agreed with Eastern and Boeing acquiesced. By late summer 1978 the 7N7 was up to design 761-280 (having started at 761-1). 

​Technological improvements like high bypass turbofan engines were incorporated into the 7N7. The 7N7 still looked very much like a 727 in some aspects. It had the same T-tail and the same fuselage cross-section, nose and cockpit of the tri-jet. The two engines were however placed under the all new wing. In hindsight the aircraft looks like a 727 and 757 kit bashed together in an ungainly fashion.

​When Eastern and BA announced their deal to place launch orders for 21 and 19 of the series 200 version on August 31, 1978 the 7N7 design was still miles away from finalisation. Gradually design decisions moved it away from the 727 look and ultimately, Boeing aligned the 7N7 with the 7X7. The T-tail was dropped for aerodynamic reasons and new cockpit designs reduced the crew from three to two. 

The above model was made for Delta and is discussed further here:

Boeing 7N7 Delta Archives

The 7N7 evolved without the T-tail but still had the 727 nose

​Gradually the idea gained traction that the 7N7 should reuse the cockpit of the larger 767 (that the 7X7 had become) to create a common type rating for both aircraft and simplify the 7N7 programme. That was the final death of the 727 inspired 7N7 and saw a new cockpit design producing the familiar 757 looks with the flattened wider nose. In addition, the APU, electrical power generation system and air conditioning were shared between both jets. The eventual production 757-200 was model 761-340 and it wasn’t until March 1979 that the design was finalised enough to get the contracts with Eastern and BA signed.

This 1980 brochure shows a closer finish to the 757 shape and the 1970s house colours

​Production began at Boeing’s Renton plant on March 23, 1979 although orders for the type were sparse. The first Boeing 757, N757A, was rolled out of the plant on January 13, 1982 and flew for the first time on February 19 with project test pilot John Armstrong at the controls. There was an engine stall during the maiden flight but the engine was restarted. There is a great video on Youtube of the 757's maiden flight:

​Five 757s were used during the certification programme with the first for Eastern flying in May 1982. One of the Eastern aircraft was used for a South-east Asian tour and displaying at Farnborough in September 1982. British Airways first 757 didn’t on the other hand fly until late October with type certification finally achieved on December 17. This was the same day the first aircraft was handed over to Eastern. 

N505EA ship 6 at Farnborough in 1982. Boeing_757-225_Farnborough_1982_Fitzgerald.jpg: Steve Fitzgeraldderivative work: Altair78 [GFDL 1.2 (http://www.gnu.org/licenses/old-licenses/fdl-1.2.html) or GFDL 1.2 (http://www.gnu.org/licenses/old-licenses/fdl-1.2.html)]

​The 757 would in time become a major success for Boeing and sell over 1,000 units, however throughout the late stages of its development, and the first half-decade of its service life, it would prove a slow seller. In the next part of this story we’ll take a look at competition for engine orders and the orders for the aircraft itself. For part 2 click here:

The 757 Story Pt2: Engines & Sales

References
1983. Making it Fly: the Boeing 757. Seattle Times
2015. Friday Flashback: the Boeing 757. Airways.
Boeing: Plane Makers of Distinction.