Boeing 747-100

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Ladies and Gentlemen I give you a timeless classic! The original, the beautiful, Boeing 747-100! Since this double-deck monster of an aircraft first slipped its way through the Hangar doors and onto the tarmac at Boeing’s Everett Factory, it captured the imaginations and the hearts of the entire world. It was the aircraft that took the aviation industry from the rich and affluent, and made it a form of mass-transit. A crisp and magnificent design, the 747 even to this day turns heads and has become a byword for impossible size!

The concept of the wide-body jet airliner stemmed largely from military transport proposals done in the early 1960’s. In 1963, the United States Air Force started a series of study projects on a very large strategic transport aircraft. Lockheed pioneered the concept of jet powered wide-body transport aircraft with the C-141 Starlifter, but the requirements of the U.S. Air Force demanded a much larger model for work in the ongoing Vietnam War. These studies led to initial requirements for the CX-Heavy Logistics System (CX-HLS) in March 1964 for an aircraft with a load capacity of 180,000lbs, a speed of 500mph, and an unrefueled range of 5,000 miles. The payload bay had to be 17ft wide by 13.5ft high and 100ft long with access through doors at the front and rear. Featuring only four engines, the design also required new engine designs with greatly increased power and better fuel economy.

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The prototype 747-100 on its trails over Washington state.

On May 18th, 1964, airframe proposals arrived from Boeing, Douglas, General Dynamics, Lockheed and Martin Marietta; while engine proposals were submitted by General Electric, Curtiss-Wright, and Pratt & Whitney. After a downselect, Boeing, Douglas and Lockheed were given additional study contracts for the airframe, along with General Electric and Pratt & Whitney for the engines. Eventually, the contract for such a massive cargo transport was lost to Lockheed, who developed the C-5 Galaxy of 1968, but Boeing’s research into creating their own CX-HLS concept was retained for use on a possible passenger variant.

By 1965, air travel had grown substantially, thanks primarily to Boeing’s previous and first international jet airliner the Boeing 707. Before Boeing had even lost the CX-HLS contract, Pan American World Airways president Juan Trippe was already asking the company to help develop an update on the Boeing 707’s that formed a majority of his fleet. The requirements of the new plane were essentially just bigger in every conceivable way, longer range, greater capacity, basically so as to reduce the number of aircraft needed to operate flights. At the time, whilst the 707 and its rivals the DC-8 and the VC10 were popular, their lack of capacity meant that frequencies of flights had to be increased in order to supply demand, the result being huge amounts of congestion at airports. Trippe hoped that this balance could be redressed by having a smaller fleet of larger aircraft that could supply an equal demand, and allow for the smaller 707’s to be redistributed on less congested routes.

Coming off his work on the highly successful Boeing 737, Boeing designer Joe Sutter was given the task of managing the design team behind what had already been designated the Boeing 747 project. Sutter initiated a design study with Pan Am and other airlines, to better understand their requirements. At the time, it was widely thought that the 747 would eventually be superseded by supersonic transport aircraft. Boeing responded by designing the 747 so that it could be adapted easily to carry freight and remain in production even if sales of the passenger version declined.

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An Iberia example, the company was one of the original airlines to take delivery of this aircraft way back in 1970.

In April 1966, Pan Am ordered 25 747-100 aircraft for $525 million. During the ceremonial 747 contract-signing banquet in Seattle on Boeing’s 50th Anniversary, Juan Trippe predicted that the 747 would be “… a great weapon for peace, competing with intercontinental missiles for mankind’s destiny”. As launch customer, and because of its early involvement before placing a formal order, Pan Am was able to influence the design and development of the 747 to an extent unmatched by a single airline before or since.

Original plans derived from the CX-HLS were altered to suit a more conventional passenger aircraft configuration. The original high-wing consideration was not used, and the original proposal of a full-length double-deck fuselage was dropped, not returning until the Airbus A380 in 2005. Instead, a wider single deck design was opted for, and the cockpit was, therefore, placed on a shortened upper deck so that a freight-loading door could be included in the nose cone; this design feature produced the 747’s distinctive “bulge”. Early considerations for the use of space behind the cockpit on the upper deck were not clear, and eventually was left up to the airlines themselves to decide what to do with it.

Power for the 747 was derived from specially built Pratt & Whitney JT9D high-bypass turbofan engines. General Electric, who had pioneered the concept, could not assist as they had become committed to Lockheed’s C-5 Galaxy project, and thus the contract went to Pratt & Whitney. The JT9D had a thrust output of 46,500lbf, giving the 747 a top speed of 594mph and a range of 5,300 miles. The JT9D was later added to by the Rolls Royce RB211, developed for the Lockheed Tristar, which had a thrust output of 50,100lbf.

The project was designed with a new methodology called fault tree analysis, which allowed the effects of a failure of a single part to be studied to determine its impact on other systems. To address concerns about safety and flyability, the 747’s design included structural redundancy, redundant hydraulic systems, quadruple main landing gear and dual control surfaces. Additionally, some of the most advanced high-lift devices used in the industry were included in the new design, to allow it to operate from existing airports. These included slats running almost the entire length of the wing, as well as complex three-part slotted flaps along the trailing edge of the wing. The wing’s complex three-part flaps increase wing area by 21% and lift by 90% when fully deployed compared to their non-deployed configuration.

Of course when building the largest commercial airliner of the day, Boeing needed a place to do such a thing, but the current factory for Boeing 707, 727 and 737 production was far too small for such a behemoth, especially if Boeing wanted to maintain mass-production of its smaller jets without 747’s taking up all the space on the shop floor. The result was the construction of a brand new factory at Paine Field near Everett, 30 miles north of Seattle. The specialist factory built between 1966 and 1968 became the largest structure in history, at a volume of 13,385,378 m3. This plant is still used today, continuing to build Boeing 747’s as well as newer wide-body aircraft 767’s, 777’s and 787’s.

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Continental Airlines received their order for 747-100’s in 1970, and operated them thoroughly until the mid-1990’s.

The first delivery to Pan Am was marked to be done by the end of 1969, 28 months after the contract was signed and at least one year shorter than the usual time taken to develop an aircraft. Work was done at something of a breakneck pace, and those who were working on the project were given the nickname “The Incredibles”. Boeing had taken a massive risk with the 747, but had to come through with their strategic planning. Components were tested to destruction long before the first prototype aircraft had been constructed. Gigantic mock-ups were used to simulate evacuations, with 560 volunteers having to escape the plane within the FAA’s maximum 90-second rule, resulting in a variety of injuries. Tests also involved taxiing such a large aircraft. Boeing built an unusual training device known as “Waddell’s Wagon” (named for a 747 test pilot, Jack Waddell) that consisted of a mock-up cockpit mounted on the roof of a truck. While the first 747s were still being built, the device allowed pilots to practice taxi maneuvers from a high upper-deck position.

On September 30th, 1968, the first 747-100 was rolled out of the Everett assembly building before the world’s press and representatives of the 26 airlines that had ordered the airliner. Over the following months, preparations were made for the first flight, which took place on February 9th, 1969, with test pilots Jack Waddell and Brien Wygle at the controls and Jess Wallick at the flight engineer’s station. Despite a minor problem with one of the flaps, the flight confirmed that the 747 handled extremely well. During later stages of the flight test program, flutter testing showed that the wings suffered oscillation under certain conditions. This difficulty was partly solved by reducing the stiffness of some wing components. However, a particularly severe high-speed flutter problem was solved only by inserting depleted uranium counterweights as ballast in the outboard engine nacelles of the early 747’s.

On January 15th, 1970, First Lady of the United States Pat Nixon christened Pan Am’s first 747, at Dulles International Airport (later Washington Dulles International Airport) in the presence of Pan Am chairman Najeeb Halaby. Instead of champagne, red, white, and blue water was sprayed on the aircraft. The 747 entered service on January 22nd, 1970, on Pan Am’s New York–London route, and soon full distribution of the fleet was begun by the airline. The 747, despite all its orders, had a rocky entrance into service when the recession of the early 1970’s struck. During the period between 1969 and 1970, Boeing only sold two 747’s globally, and it would be three years before another American carrier bought one. 747’s that had already been purchased were found to be flying at less than half capacity, and thus some carriers chose to replace them with its smaller rivals the DC-10 or L-1011 Tristar. American Airlines relegated their 747’s to Cargo service, being replaced by DC-10’s, and wouldn’t use another in passenger operations until the late 1980’s when it hired three 747SP’s for the New York – London route. Delta Air Lines was another who chose to sell off the 747’s early, replacing them with a fleet of L-1011’s. Delta would not operate a 747 again until it acquired Northwest in 2009.

Eventually order was restored, and the 747-100 began selling again, and was able to increase the number of passengers using them. A majority of flag-carriers took on the 747 for their longer range services, primarily Transatlantic or Transpacific services. Carriers included Air France, BOAC (later British Airways), United Airlines, Northwest Airlines, Lufthansa, Trans World Airlines, Air Canada and many, many more. The original 747-100 cost $24m per unit, and 167 of these aircraft were built when production ended 1976, but by this time the -100 had been split into a variety of derivatives.

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A 747-100 in the transitional livery between the former British flag carrier, BOAC, and the new one, British Airways.

Aside from the larger and longer-range -200 that was unveiled in 1971, the -100 remained in production in the form of the -100B, -100SR and -100SP. The first variant, the -100SR, was unveiled in 1973 as a specifically built short-range version for the Japanese market to supply their demand for larger aircraft on busy commuter routes, with 29 examples built and split between Japan Air Lines and All Nippon Airlines. This was followed in 1976 by the very obscure Boeing 747SP, a short-bodied 747 designed to be lightweight for maximum range, primarily to work Pan Am’s New York – Tokyo service, of which 45 of these aircraft were built.

The final variant of the -100 to be built came in 1979 as the 747-100B, which took much of the enhanced technology from the -100SR, such as the stronger airframe and landing gear design to allow it to carry more passengers. This was added to by increased fuel capacity for longer range operations, making it comparable to the 747-200. However, the -100’s outdated design combined with the announcement of the 747-300 and advanced versions of the 747-200 already in production meant that only 9 of these aircraft were built, and only airlines of the Middle Eastern market took interest, these being Iran Air and Saudi Arabian Airlines.

Another curious derivative came in 1974, when a 1970 built former American Airlines unit was converted to carry the upcoming Space Shuttle project. After early retirement from American Airlines due to the aforementioned recession, the nearly new aircraft was taken up by NASA, stripped out internally, and fitted with special mounting struts onto which the Shuttle craft was lowered. Two former commercial 747’s were converted for this task, the other being a former Japan Air Lines 747SR, which joined its sister aircraft in 1988. Both aircraft were retired in 2012 following the conclusion of the Space Shuttle program, but have now been preserved.

The original 747-100’s remained an important part of many airline fleets throughout the 1980’s and even into the late 90’s, including United Airlines, Air Canada, Air France, British Airways, Iberia, Trans World Airlines, Northwest Airlines and Virgin Atlantic. Since then many 747-100’s were converted into freighters, whilst others were brought into the service of armed forces as VIP transport and troop transport aircraft. As of 2016, 8 remain in active service, all but one of which is with the Iranian Air Force. Five have also been preserved, including the original 747 prototype City of Everett and, as mentioned, the two former Space Shuttle carrier aircraft.

However, the 747-100 has also had a string of notable crashes, some of which are among the worst, with 10 hull losses noted. The first two 747-100’s destroyed were by the work of terrorists, who exploded the empty aircraft after the hostages had been removed, resulting in no loss of life among the passengers.

The first fatal crash involving a 747 was that of Lufthansa 540, which crashed after take-off from Nairobi on 20th November, 1974, killing 59 of its 157 passengers. The result was found to be due a stall caused by the leading edge slats having been left in retracted position. Even though the trailing edge flaps were deployed, without the slats being extended the aircraft’s stall speed was higher and the maximum angle of attack was lower. As a result, the aircraft was unable to climb out of the ground effect.

Aside from these, the 747-100 has the unfortunate distinction of being the title holder for worst aviation incident and worst aviation incident involving a single aircraft.

On March 27th, 1977, the highest death toll in any aviation accident in history occurred when KLM 4805 collided on the runway with Pan Am 1736 in heavy fog at Tenerife Airport, resulting in 583 fatalities. The cause was determined that due to fog and miscommunication, the KLM crew chose to begin their take-off roll before the Pan Am flight had exited the runway.

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American Airlines operated a larger fleet at first, but a lack of demand and the onset of the 1973 Energy Crisis saw them retire most as early as 1974.

On August 12th, 1985, Japan Air Lines Flight 123, a 747SR, crashed near Mount Osutaka, leaving 520 dead and only 4 survivors, the worst single aviation incident in history. The reason for this crash was due to improper repair of a tail-strike incurred six years earlier that weakened the structure of the vertical stabiliser, which separated in-flight and disabled the aircraft’s hydraulic systems.

On December 21st, 1988, a terrorist bomb planted aboard Pan Am 103 by Libyan extremists caused the 747-100 to explode in-flight above the town of Lockerbie in Scotland. All 259 people on board were killed, together with 11 people in the town below when flaming pieces of the wreckage rained down on the community. It was later determined the attack was ordered by then Libyan dictator Colonel Muammar Gaddafi.

On February 24th, 1989, United Airlines Flight 811 operating out of Honolulu bound for Sydney suffered an explosive decompression that ripped a large section of the starboard side away near the front, resulting in 10 seats being ejected from the aircraft and the deaths of 9 passengers, the aircraft later returning safely to Honolulu. It was later determined that a short circuit in the ageing plane caused an uncommanded rotation of the latch cams, which forced the weak locking sectors to distort and allow the rotation, thus enabling the pressure differential and aerodynamic forces to blow the door off the fuselage, ripping away the hinge fixing structure, the cabin floor and side fuselage skin, causing the massive explosive decompression.

Perhaps the most controversial crash of a 747-100 however was TWA 800, which exploded and crashed over the Long Island Sound shortly after departure from New York on July 17th, 1996, killing all 230 aboard. For many years there was huge speculation as to the cause of this crash, some blaming the U.S. Navy, which was doing missile testing in the area at the time of the crash, a theory that many still believe today. The official cause was eventually determined to be a spark from a wire in the centre fuel tank caused the explosion.

Today, like many of those early wide-body aircraft of the 1970’s, the 747-100 is an incredibly rare bird to find. As mentioned, the remainder of the fleet is under the ownership of the Iranian Air Force, and a majority of the former mainline fleets were retired in the 1990’s and promptly scrapped. Though there are several on display in museums around the world, it’s doubtful you’ll get one of these beautiful, endearing and pioneering aircraft flying over familiar skies.