Boeing’s unexpected hit, an aircraft whose direct descendants continue to be produced today, nearly 50 years since the first of these magnificent little aircraft jetted off into the sky, pioneered by the original Boeing 737-100.
The origins of the Boeing 737 go back to their previous domestic jet airliner, the Boeing 727. The concept was to create a small jet aircraft that could supplement the 727’s, which, though built for a domestic market, were still too large for many airports or routes of lower capacity. Preliminary design work began on May 11th, 1964, and Boeing’s intense market research yielded plans for a 50- to 60-passenger airliner for routes 50 to 1,000 miles long. The announcement of the Boeing 737 project caught the attention of German flag carrier Lufthansa, who became the launch customer on February 19th, 1965, with an order for 21 aircraft at a cost of $67m ($508m today). Lufthansa also helped to contribute to the final outcome of the 737 project as discussions with them highlighted a desire for more than 60 seats, this eventually being increased to 100 as per their request.
On April 5th, 1965, Boeing announced an order by United Airlines for 40 737s. United wanted a slightly larger airplane than the original 737. So Boeing stretched the fuselage 36 inches ahead of, and 40 inches behind the wing. The longer version was designated 737-200, with the original short-body aircraft becoming the 737-100.
At the time however, Boeing, for all its success with the 727 and 707, were lagging far behind when it came to satisfying the short-haul market, with the rival Douglas DC-9, Fokker F.28 and BAC 1-11 beginning to enter service already. As such, Boeing decided to take a bit of a short cut on development by carrying over 60% of the structure and systems of the Boeing 727, most noticeably the aircraft’s cross-section and shape, which itself was derived from the earlier 707. This fuselage permitted six-abreast seating compared to the rival BAC-111 and DC-9’s five-abreast layout.
While at the time the trend was for engines to be mounted on the rear of the fuselage, the 737 differed by having its engines mounted below the wings. Design engineers decided to mount the nacelles directly to the underside of the wings to reduce the landing gear length and kept the engines low to the ground for easy ramp inspection and servicing. Many thickness variations for the engine attachment strut were tested in the wind tunnel and the most desirable shape for high speed was found to be one which was relatively thick, filling the narrow channels formed between the wing and the top of the nacelle, particularly on the outboard side.
The engine type chosen was the Pratt & Whitney JT8D-1 low-bypass ratio turbofan engine, delivering 14,500lbf thrust, providing the 737 with a top speed of 544mph and a range of 1,540 miles. With the wing-mounted engines, Boeing decided to mount the horizontal stabilizer on the fuselage rather than the T-tail style of the Boeing 727. Like the 707, the 737 was fitted with Target-type Reverse Thrusters, with two hydraulically driven buckets coming over the engine exhaust to redirect flow forwards.
Boeing 737’s were assembled at the Boeing factory at what was then Boeing Field (now King County International Airport), as opposed to Boeing’s original factory at Renton. This was due to the Renton factory being full to capacity with 707 and 727 construction. Assembly was later moved to Renton after the first 271 examples were built in late 1970.
The first of six -100 prototypes rolled out in December 1966, and made its maiden
flight on April 9th, 1967, piloted by Brien Wygle and Lew Wallick. On December 15th, 1967, the Federal Aviation Administration certified the -100 for commercial flight, issuing Type Certificate A16WE. The 737 was the first aircraft to have, as part of its initial certification, approval for Category II (ILS) approaches. Lufthansa received its first aircraft on December 28th, 1967, and on February 10th, 1968, became the first non-American airline to launch a new Boeing aircraft.
However, Lufthansa would be the only significant customer to purchase the 737-100, with only 30 of these aircraft produced. Though the first, most customers were drawn by the increased size and range of the -200, which, by comparison, had 1,114 members built by the time production ended in 1988. The final -100 was constructed in 1969, and delivered to Malaysia–Singapore Airlines (later to be split into Malaysia and Singapore Airlines).
737-100’s circulated the world for many years, and some even ended up back in their native United States. The last known examples to fly were in the mid to late 1990’s, by which time a majority of the fleet had been scrapped. Some continued into the 2000’s, primarily working in South America, where apparently one example remains in store.
No 737-100’s were lost to accidents, but one was hijacked during a period in the early 1970’s when they were worryingly common and usually perpetrated by members associated with the nation of Palestine. On December 17th, 1973, agents of the Black September militant group attacked Leonardo da Vinci–Fiumicino International Airport in Rome. After blasting their way onto the tarmac from the departure area, the group first threw phosphorous incendiary grenades at Pan Am Flight 110, a Boeing 707 preparing to depart for Mehrabad, resulting in 30 deaths as the aircraft was engulfed in flames.
The group then made their way to a waiting Lufthansa Boeing 737-100 bound for Munich, taking 10 people hostage. The plane was first flown to Athens, where the terrorists demanded by radio the release of two Palestinian gunmen responsible for a previous attack on Athens Ellinikon International Airport in 1968. Though the terrorists threatened to crash the plane in central Athens, the result was the killing of one hostage and the injury of another, both of whom were dumped onto the tarmac before the flight departed.
After being denied entry to Beirut and Cyprus, the plane landed in Damascus in Syria, and after food and fuel had been replenished, the aircraft departed again after 3 hours. Eventually the flight landed without permission in Kuwait, and after an hour’s negotiations, the hostages were allowed to go free and the hijackers were taken into custody. They were later allowed to return to Palestine and supposedly tried for an unauthorized operation. The overall death toll from the attack was 34, including 1 hostage, 30 passengers on Flight 110, and three ground crew members in Rome.
Even though the 737-100 was the pioneer of the 737 family, it’s interesting how it never really hit it off as well as its following models. But, even though it is a very obscure aircraft with only one preserved, the 737-100 does continue to hold the distinction of being the original, the premier of a commercial airliner family that has now sold over 9,000 examples to airlines all over the world and remains in production 50 years after the idea was first drawn up!