YouTube – Boeing 707
Initial Climb Rate:
4 x 18,000 lbs. ea.
141 – 189
152 ft. 11 in.
145 ft. 9 in.
The idea for the Boeing 707 came about in the late 1940’s when Boeing executives saw a demonstration of the first jet airliner built in Great Britain. Boeing felt that their experience in developing the world’s first swept wing bomber, plus their vast commercial airliner experience, would result in their production of a superior aircraft.
The specifications for the Boeing 707 started being formulated in the early 1950’s. Boeing would need to convince civil aviation carriers that jet powered aircraft would replace propeller-driven planes. It was decided that the best course to follow would be to demonstrate their jet aircraft to the airlines.
To keep the development of their first commercial jet aircraft a secret as long as possible, Boeing gave the prototype the designation of 367-80, or “Dash Eighty”. The new aircraft program was approved in April of 1952 with construction completed on May 15, 1954. It first took to the sky on July 15, 1954.
The Boeing 707 Dash Eighty was primarily hand-built and had no passenger cabin. Its fuselage was wide enough for two seats, an isle, and three seats. However, when the first production Boeing 707 model 120 was built, its cabin was made wider to accommodate three by three seating.
In addition to a wider cabin, a number of changes were needed to improve engine reliability, braking, and in-flight handling before the new Boeing 707 would be ready for sale to airlines. A ventral fin was added and the tail fin was made higher to improve directional stability.
The Boeing 707 impressed the airlines. The first 20 production aircraft were ordered by Pan American Airways in October of 1955 with deliveries starting in October of 1958. Other major airline orders soon followed, making Boeing the largest commercial jet aircraft producer. More Boeing 707 aircraft were produced than any other airliner of its time. Production of the aircraft continued until 1979 when demand for larger aircraft brought about its successors.
On November 15, 1965 a Boeing 707 became the first aircraft to complete a pole to pole around the world flight, flying over both the North and South Poles.
Throughout the years, the Boeing 707 was produced in different models with different wingspans, lengths, engines, and configurations, for cargo handling and numerous military applications.
It appears that only 10 passenger versions of the airliner are still flying, but many commercial and military versions carry on to this date.
A total of 1,011 Boeing 707 airliners and over 800 military aircraft were produced.
Flying the Boeing 707 (Dash Eighty prototype)
Test pilots described the Boeing 707 prototype as powerful and easy to fly. The following are some of their observations while flying the lightly loaded prototype when it was first introduced.
The Boeing 707 may be started either with on-board compressed air systems or with ground starting equipment. Standard procedure is to start a single engine from a ground unit, and use the running engine to start the other engines.
Although the Boeing 707 is fairly easy to maneuver on the ground, it can not turn as sharply as other aircraft of its size. That makes maneuvering in tight spaces more difficult.
Once the lightly loaded Boeing 707 is positioned on the runway center line, the throttles are advanced to take off power. At about 92 mph the rudder gains full control authority. Rotation is at 115 mph and take off at 138 mph. The aircraft’s angle of attack barely changes with landing gear and flap retraction. Initial climb rate is about 4,000 feet per minute and speed increases rapidly, so it is important to get the flaps retracted quickly before their speed limit of about 210 mph in the take off position is reached.
With a climb rate speed between 288 and 345 mph, it takes about eight minutes to climb to 31,000 feet. The flight controls are similar to propeller-driven aircraft, while the instruments take some getting used to. Many of the dials, such as engine rpm, are only two inches across, and could stand to be made larger and easy to read. Aircraft controls are light and well balanced. They provide just the right combination of control and response.
The trim of the horizontal stabilizer is electrically actuated, with optional manual control in case of electrical failure. In addition to ailerons, the aircraft is also equipped with spoilers on each wing. The spoilers are used in conjunction with the ailerons to control the lateral movement of the aircraft during regular flight, except when deployed fully when landing. Then they help the aircraft descend at a steep angle without gaining speed. Lowering the flaps or extending the spoilers has no noticeable effect on lateral aircraft control.
An obvious difference between the Boeing 707 and propeller-driven aircraft of similar size is the quicker roll rate and response to aileron controls. The control wheel needs only to be turned incrementally to obtain an immediate roll response. The aircraft has relatively the same response to control inputs at all speeds, from slowest to highest.
Some idea of the maneuverability of the Boeing 707 can be found viewing the demonstration of the aircraft by Tex Johnson when he did two successive barrel rolls with it.
Throttling back and raising the nose of the aircraft until it stalls produces no surprises. The Boeing 707 is controllable until the moment of the stall, and there is lots of warning that a stall is imminent. Mild buffeting begins about 23 mph prior to the stall speed being reached and gets progressively harsher. The same is true whether the aircraft is stalled in clean or dirty configurations.
Stall recovery is unremarkable. Pushing the throttles violently forward resulted in the engines quickly spooling up with no hysterics except for a strong pressure pushing one back in the pilot’s seat. This resulted in quick stall recoveries.
An emergency descent was performed from 33,000 feet while flying at a speed of about 355 mph. The throttles are closed and full spoilers actuated. The spoilers can be actuated at any aircraft speed without having to observe any maximums. At 310 mph the landing gear may be lowered. After they are down it is possible to increase speed by about 15 mph. The aircraft is easily controllable while descending at a rate of about 12,200 feet per minute.
Landings are made with the goal of achieving a 138 mph speed crossing over the fence. Lowering of the gear produces a great deal of aircraft slowing drag, with no noticeable affect of control. Flaps can be lowered to approach position at 207 mph. Once they are deployed, some nose down attitude is observed. A little backward stick will control the attitude. It seems more natural to control descent by the feel of the quick engine response to throttle changes, rather than observing the instruments. At 160 mph, full flaps are applied and the landing angle of the aircraft remains virtually unchanged.
During flare-out the aircraft tends to balloon slightly, but a slow steady forward push of the control column soon brings it under control. The Boeing 707 holds it rate of descent until the wheels touch the runway, and their is no tendency to bounce. At its relatively high landing speed, the aircraft tends to stay in ground effect for quite a way down the runway. Once more landing experience is gained, the speed can probably be lowered. On touchdown the spoilers are immediately deployed to their full position for more effective braking and steering. It seems that the engineers got everything right with their Boeing 707.
RC Boeing 707
We received the above picture with the following email: “This is DemonDriver, aka Chris, of RC Groups. I just wanted to share with you a picture of me with my RC Boeing 707 in Pan Am colors that I maidened a few months ago. It is 72 in. long, has a 70 in. wingspan, and weighs around 7 lbs. with nav lights and retracts. Power is by two HET 70 mm electric ducted fans generating about 4 lbs of thrust each.” Thank you, Chris. You did a terrific job!