Tag Archives: Boeing 720

1 December 1984

NASA 833, a remotely-piloted Boeing 720 airliner, pulls up after a practice approach to the impact point on Rogers Dry Lake. The "X" is the planned touchdown point. The "rhino" barriers are at the runway threshold. (NASA)
NASA 833, a remotely-piloted Boeing 720 airliner, pulls up after a practice approach to the impact point on Rogers Dry Lake. The “X” is the planned touchdown point. The “rhino” barriers are at the runway threshold. (NASA)

After four years of planning and preparation, the National Aeronautics and Space Administration (NASA) and the Federal Aviation Administration (FAA) intentionally crashed a Boeing 720 airliner to test an experimental fuel additive intended to reduce post-crash fires, and to assess passenger survivability. An anti-misting agent was added to standard commercial JP-5 jet fuel to create AMK, or “Anti-Misting Kerosene.” The airliner’s fuel tanks were filled with the AMK mixture, totaling 16,060 gallons (10,794 liters). Instrumented crash test dummies were placed in the passengers seats.

Passengers relaxing before a flight aboard NASA’s Boeing 720, N833NA. (NASA ECN-28307)

NASA 833, the Boeing 720-027 airliner, FAA registration N833NA, was a remotely-piloted aircraft. NASA test pilot Fitzhugh Lee (“Fitz”) Fulton, Jr., flew NASA 833 from a ground station, the NASA Dryden Remotely Controlled Vehicle Facility. More than 60 flights had been made prior to the actual test.

Fitz Fulton in the CID.
Fitz Fulton in the NASA Dryden Remotely Controlled Vehicle Facility

The test was planned so that the airliner would make a shallow 3.8° approach to a prepared runway on the east side of Rogers Dry Lake at Edwards Air Force Base. It was to land on its belly in a wings-level attitude, then slide into a group of barriers, called “rhinos,” which would slice open the wing tanks. The fuselage and passenger cabin would remain intact. NASA and the FAA estimated that this would be “survivable” for all occupants.

Just before touchdown, the Boeing 720 entered a "Dutch roll." The airliner's nose yawed to the left and the left wing dipped, striking the ground sooner than was planned. All four engines are still at full throttle. NASA 833 is to the right of the runway center line. (NASA)
Just before touchdown, the Boeing 720 entered a “Dutch roll.” The airliner’s nose yawed to the left and the left wing dipped, striking the ground sooner than was planned. All four engines are still at full throttle. NASA 833 is to the right of the runway center line. (NASA)

As the Boeing 720 descended on its Final Approach, its nose yawed to the right and the airplane went to the right of the runway center line. It then yawed back to the left and entered an out-of-phase oscillation called a “Dutch roll.” The decision height to initiate a “go-around” was 150 feet (45.7 meters) above the surface of the lake bed. Fitz Fulton thought he had enough time to get NASA 833 back on the center line and committed to the test landing. However, the Dutch roll resulted in the airliner’s left wing impacting the ground with the inboard engine on the left wing (Number Two) just to the right of the center line.

NASA 833 slews left as it approaches the test apparatus. The Boeing 720 has reached the intended touchdown point but is out of position, still to the right of center line and misaligned. (NASA)
NASA 833 slews left as it approaches the test apparatus. The Boeing 720 has reached the intended touchdown point but is out of position, still to the right of center line and misaligned. (NASA)

According to the test plan, all four of the airliner’s engines should have been brought to idle, but they remained at full throttle. The left wing’s impact yawed the airliner to the left and, rather than the fuselage passing through the rhino barriers undamaged, the passenger compartment was torn open. Another rhino sliced into the Number Three engine (inboard, right wing), opening its combustion chamber. With the fuel tanks in the wings ruptured, raw fuel was sprayed into the engine’s open combustion chamber which was still at full throttle.

 As the airliner slides through the "rhino" barriers, they rip open the fuel tanks, the Number Three engine and the passenger compartment. The raw fuel immediately ignited. (NASA)
As the airliner slides through the “rhino” barriers, they rip open the fuel tanks, the Number Three engine and the passenger compartment. The raw fuel immediately ignited. (NASA)

The raw fuel ignited and exploded into a fireball. Flames immediately entered the passenger compartment. As the 720 slid on the runway it continued to rotate left and the right wing broke off though the fuselage remained upright.

NASA 833's right wing breaks off, rupturing the fuel tanks. Nearly 8,000 gallons (30,000 liters) of jet fuel pours out into the fireball. (NASA)
NASA 833’s right wing breaks off, rupturing the fuel tanks. Nearly 8,000 gallons (30,000 liters) of jet fuel pours out into the fireball. (NASA)

As the right wing came off the ruptured fuel tanks emptied most of the raw fuel directly into the fireball.

The flaming wreckage of NASA 833 slides to a stop on Rogers Dry Lake. Fire fighters needed more than one hour to extinguish the fire. (NASA)
The flaming wreckage of NASA 833 slides to a stop on Rogers Dry Lake. Fire fighters needed more than one hour to extinguish the fire. (NASA)

Over an hour was required to extinguish the flames. The test of the flame-reducing fuel additive was a complete failure. Test engineers estimated that 25% of the occupants might have survived the crash, however, it was “highly speculative” that any could have escaped from the burning, smoke-filled passenger compartment.

Fithugh L. "Fitz" Fulton, Jr. (NASA)
Fitzhugh Lee “Fitz” Fulton, Jr., with NASA 905, a Shuttle Carrier Aircraft, and Enterprise (OV-101). (NASA)
Fitz Fulton, 1942 (The Cohiscan)

Fitzhugh Lee Fulton, Jr., was born at Blakely, Georgia, 6 June 1925, the first of two sons of Fitzhugh Lee Fulton, a merchant seaman, and Manila Fulton. He attended Columbus High School, Columbus Georgia, graduating in 1942. He entered College at Alabama Polytechnic Institute (now known as Auburn University) and the University of Oklahoma. He was awarded a bachelor of arts degree from Golden Gate University, San Francisco, California.

Fulton entered the U.S. Army Air Corps in 1943, and was trained as a pilot. He married Miss Erma I. Beck at Tucson, Arizona, 16 December 1945. They would have three children.

Following World War II, participated in Operation Crossroads, the atomic bomb tests at Bikini Atoll, July 1946. Lieutenant Fulton flew the Douglas C-54 Skymaster four-engine transport during the Berlin Airlift, making 225 sorties, and then the Douglas B-26 Invader light attack bomber during the Korean War.

Captain Fitz Fulton, U.S. Air Force, in teh cockpit of a Douglas B-26 Invader, circa 1952. (Air & Space Magazine)
Captain Fitz Fulton, U.S. Air Force, in the cockpit of a Douglas B-26 Invader, circa 1952. (Air & Space Magazine)

Fulton graduated from the Air Force Test Pilot School in 1952. He served as project test pilot for the Convair B-58 Hustler supersonic bomber and flew the B-58 to a World Record Altitude of 26,017.93 meters (85,360.66 feet) on 14 September 1962.¹

Major Fitz Fulton in the cockpit of a Convair B-58. (Jet Pilot Overseas)
Major Fitz Fulton in the cockpit of a Convair B-58. (Jet Pilot Overseas)

At Edwards Air Force Base, he flew the B-52 “mother ships” for the X-15 Program. He flew the North American XB-70A Valkyrie faster than Mach 3. When Fulton retired from the Air Force in 1966, he was a lieutenant colonel assigned as Chief of Bomber and Transport Test Operations.

Fitz Fulton continued as a research test pilot for NASA, flying as project pilot for the YF-12A and YF-12C research program. He flew all the early test flights of the NASA/Boeing 747 Shuttle Carrier Aircraft and carried the space shuttle prototype, Enterprise. By the time he had retired from NASA, Fulton had flown more than 16,000 hours in 235 aircraft types.

Fitzhugh L. Fulton, Jr., died at Thousand Oaks, California, 4 February 2015, at the age of 89 years..

Lieutenant Colonel Fitzhugh Lee Fulton, Jr., with a North American Aviation XB-70A Valkyrie.
Colonel Joseph Frederick Cotton and Lieutenant Colonel Fitzhugh Lee Fulton, Jr., with a North American Aviation XB-70A Valkyrie.

NASA 833 (c/n 18066) was ordered by Braniff Airways, Inc., as N7078, but the sale was not completed. The airplane first flew 5 May 1961 and it was delivered to the Federal Aviation Administration as a test aircraft one week later, 12 May 1961, registered N113. A few years later the identification was changed to N23, then back to N113, and then once again to N23. In 1982, the Boeing 720 was transferred to NASA to be used in the Controlled Impact Demonstration. At this time it was registered as N2697V. A final registration change was made to N833NA.

NASA 833 at Edwards Air Force Base, prior to the Controlled Impact Demonstration. (Paul)

The Boeing 720 was a variant of the Model 707, intended for short to medium range flights. It had 100 inches (2.54 meters) removed from the fuselage length and improvements were made to the wing, decreasing aerodynamic drag, though it retained the span of the 707.

The Boeing 720 was powered by four Pratt & Whitney Turbo Wasp JT3C-7 turbojet engines, a civil variant of the military J57 series. The 720B was equipped with the more efficient P&W JT3D-1 turbofan engines. The JT3C-7 was a “two-spool” axial-flow engine with a 16-stage compressor (9 low- and 7 high-pressure stages), 8 combustion tubes, and a 3-stage turbine (1 high- and 2 low-pressure stages). It was rated at 12,030 pounds of thrust (53.512 kilonewtons) for takeoff. The JT3D-1 was a dual axial-flow turbofan engine, with a 2-stage fan section 13-stage compressor (6 low- and 7 high pressure stages), 8 combustion chambers and a 4-stage turbine (1 high- and 3 low-pressure stages). This engine was rated at 14,500 pounds of static thrust (64.499 kilonewtons) at Sea Level, and 17,000 pounds (75.620 kilonewtons), with water injection, for takeoff (2½ minute limit). Almost half of the engine’s thrust was produced by the fans. Maximum engine speed was 6,800 r.p.m. (N1) and 10,200 r.p.m. (N2). It was 11 feet, 4.64 inches (3.471 meters) long, 4 feet, 5.00 inches (1.346 meters) wide and 4 feet, 10.00 inches (1.422 meters) high. It weighed 4,165 pounds (1,889 kilograms). The JT3C could be converted to the JT3D configuration during overhaul.

The maximum cruise speed of the Boeing 720 was 611 miles per hour (983 kilometers per hour) and maximum speed was 620 miles per hour (1,009 kilometers per hour). The range at at maximum payload was 4,370 miles (7,033 kilometers).

Boeing built 154 720 and 720B airliners from 1959 to 1967.

The Federal Aviation Administration's Boeing 720-027 N113. (FAA)
The Federal Aviation Administration’s Boeing 720-027 N113. (FAA)

¹ FAI Record File Numbers 14652 and 14656

© 2018, Bryan R. Swopes

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23 November 1959

Boeing 720-022 c/n 17907, N7201U. (Boeing)
Boeing 720-022 c/n 17907, N7201U, parked on the taxiway at the south shore of Lake Washington. (Boeing)

23 November 1959: The first Boeing 720 airliner, a 720-022, registered as N7201U, made its first flight at Renton, Washington. The 720 was a development of the 707 and no prototype was built. N7201U was used by Boeing for flight testing and was then delivered to United Airlines, 1 October 1960. The airline named the new 720 Jet Mainliner Capt. F. M. Crismore. Over the next two years, United acquired 29 Boeing 720s.

N7201U was sold to Contemporary Entertainment, owned by singer Bobby Sherman and his manager, Ward Sylvester, in January 1973. It was repainted in a gold and black livery and christened The Starship. As a VIP transport, it was used by such rock bands as Led Zeppelin, Deep Purple, The Rolling Stones, Alice Cooper and Elton John. It was last chartered by Peter Frampton.

N7201U was withdrawn from service in 1977 and after being stored for several years, was broken up at Luton Airport near London, England, in 1982.

The Boeing 720 was a variant of the Model 707, intended for short to medium range flights. It had 100 inches (2.54 meters) removed from the fuselage length and improvements to the wing, decreasing aerodynamic drag.

Boeing built 154 720 and 720B airliners from 1959 to 1967.

The Boeing 720 was operated by a flight crew of four and could carry up to 149 passengers. It was 136 feet, 2 inches (41.25 meters) long with a wingspan of 130 feet, 10 inches (39.90 meters) and overall height of 41 feet, 7 inches (12.65 meters). The airplane had an empty weight of 103,145 pounds (46,785 kilograms) and Maximum Takeoff Weight of 220,000 pounds (100,800 kilograms).

The Boeing 720 was powered by four Pratt & Whitney Turbo Wasp JT3C-7 turbojet engines, a civil variant of the military J57 series. The 720B was equipped with the more efficient P&W JT3D-1 turbofan engines. The JT3C-7 was a “two-spool” axial-flow engine with a 16-stage compressor (9 low- and 7 high-pressure stages), 8 combustion tubes, and a 3-stage turbine (1 high- and 2 low-pressure stages). It was rated at 12,030 pounds of thrust (53.512 kilonewtons) for takeoff.

The JT3D-1 was a dual axial-flow turbofan engine, with a 2-stage fan section 13-stage compressor (6 low- and 7 high pressure stages), 8 combustion chambers and a 4-stage turbine (1 high- and 3 low-pressure stages). This engine was rated at 14,500 pounds of static thrust (64.499 kilonewtons) at Sea Level, and 17,000 pounds (75.620 kilonewtons), with water injection, for takeoff (2½ minute limit). Almost half of the engine’s thrust was produced by the fans. Maximum engine speed was 6,800 r.p.m. (N1) and 10,200 r.p.m. (N2). It was 11 feet, 4.64 inches (3.471 meters) long, 4 feet, 5.00 inches (1.346 meters) wide and 4 feet, 10.00 inches (1.422 meters) high. It weighed 4,165 pounds (1,889 kilograms). The JT3C could be converted to the JT3D configuration during overhaul.

The maximum cruise speed was 611 miles per hour (983 kilometers per hour) and maximum speed was 620 miles per hour (1,009 kilometers per hour). Range at at maximum payload was 4,370 miles (7,033 kilometers).

The last flight of a Boeing 720 was on 9 May 2012, when a 720B aircraft used by Pratt and Whitney Canada as a test aircraft was placed in the National Air Force Museum of Canada at Trenton, Ontario.

United Airlines' Boeing 720-022, N7201U. (Unattributed)
United Airlines’ Boeing 720-022, N7201U. The airliner’s name, “Jet Mainliner Capt. F. M. Crismore,” is visible under the cockpit windows. (Bill Larkins via Wikipedia)

© 2018, Bryan R. Swopes

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15 July 1954

Boeing test pilot Alvin M. “Tex” Johnston in the cockpit of of the 367–80. (LIFE Magazine via Jet Pilot Overseas)

15 July 1954: At 2:14 p.m., Boeing test pilots Alvin M. “Tex” Johnston and Richard L. “Dix” Loesch lifted off from Renton Field, south of Seattle, Washington, on the first flight of the Boeing 367–80, FAA registration N70700, a prototype military air tanker and commercial airliner. For the next 2 hours, 24 minutes they performed high- and low-speed handling tests before landing at Boeing Field, Seattle. When Johnston was asked how the “Dash 80” flew, he replied, “She flew like a bird, only faster.”

The prototype Boeing 367-80, N70700, takes off from Boeing Field, Seattle, Washington,15 July 1954. (Boeing)
The prototype Boeing 367-80, N70700, takes off from Renton Field, Seattle, Washington, 15 July 1954. (Boeing)

Boeing had risked $16,000,000 in a private venture to build the Dash 80 in order to demonstrate its capabilities to potential civilian and military customers, while rivals Douglas and Lockheed were marketing their own un-built jet airliners. Put into production as the U.S. Air Force KC-135 Stratotanker air refueling tanker and C-135 Stratolifter transport, a civil variant was also produced as the Boeing 707 Stratoliner, the first successful jet airliner. Though they look very similar, the 707 is structurally different than the KC-135 and has a wider fuselage.

The Boeing 707-320B Stratoliner airframe was used for the military E-3A Sentry AWACS command-and-control aircraft, the E-6 Mercury airborne command post, and other versions for reconnaissance, weather, and communications.

820 of the C-135 series and 1,010 Model 707 aircraft were built from 1957–1979.

Boeing 367-80 N70700. (San Diego Air and Space Museum Archive)
Boeing 367-80 N70700, the “Dash 80”. (San Diego Air and Space Museum Archive)

The prototype Boeing Model 367-80 was operated by a pilot, co-pilot and flight engineer. The airplane’s wing was mounted low on the fuselage and the engine nacelles were mounted on pylons under the wing, as they were on Boeing’s B-47 Stratojet and B-52 Stratofortress. The wings and tail surfaces were swept to 35°. The Dash 80 was 127 feet 10 inches (38.964 meters) long with a wingspan of 129 feet, 8 inches (39.522 meters) and overall height of 38 feet (11.582 meters). Its empty weight was 92,100 pounds (41,775.9 kilograms) and loaded weight was 190,000 pounds (86,182.6 kilograms).

In tanker configuration, the Boeing 367-80 refuels a Boeing B-52 Stratofortress. The chase plane is a Lockheed T-33A Shooting Star. (U.S. Air Force)
In tanker configuration, the Boeing 367-80 refuels a Boeing B-52 Stratofortress. The chase plane is a Lockheed T-33A Shooting Star. (U.S. Air Force)
A Boeing KC-135A Stratotanker refuels a Boeing B-52E Stratofortress. (U.S. Air Force)
A Boeing KC-135A Stratotanker refuels a Boeing B-52E Stratofortress. (U.S. Air Force)

N70700 was powered by four Pratt & Whitney Turbo Wasp JT3C engines. This engine is a civil variant of the military J57 series. It is a two-spool, axial-flow turbojet engine with a 16-stage compressor and 2-stage turbine. The JT3C-6 (used in the first production 707s) was rated at 11,200 pounds of thrust (49.82 kilonewtons), and 13,500 pounds (60.05 kilonewtons) with water/methanol injection). The JT3C is 11 feet, 6.6 inches (3.520 meters) long, 3 feet, 2.9 inches (0.988 meters) in diameter, and weighs 4,235 pounds (1,921 kilograms).

These gave the 367-80 a cruise speed of 550 miles per hour (885 kilometers per hour) and a maximum speed of 0.84 Mach (582 miles per hour, 937 kilometers per hour) at 25,000 feet (7,620 meters). The service ceiling was 43,000 feet (13,106 meters). Its range was 3,530 miles (5,681 kilometers).

American Airlines Boeing 707-123 Astrojet, N7501A, Flagship Michigan. (American Airlines)
American Airlines’ Boeing 707-123 Astrojet N7501A, Flagship Michigan. (American Airlines)

Boeing continued to use the 367–80 for testing, finally retiring it 22 January 1970. At that time, its logbook showed 2,346 hours, 46 minutes of flight time (TTAF). It was flown to Davis-Monthan Air Force Base, Tucson, Arizona, and placed in storage. In 1990, Boeing returned it to flyable condition and flew it back it to Renton where a total restoration was completed. Many of those who had worked on the Dash 80, Including Tex Johnston, were aboard.

The Dash 80 sat in the Arizona desert for twenty years. (Goleta Air and Space Museum)
The Dash 80 sat in the Arizona desert for twenty years. (Goleta Air and Space Museum)

The pioneering airplane was presented to the Smithsonian Institution and is on display at the National Air and Space Museum, Steven V. Udvar-Hazy Center. The Boeing 367-80 was designated an International Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers.

820 of the C-135 series and 1,010 Model 707 aircraft were built from 1957–1979.

(The Boeing Model 367-80 is on display at the Steven F. Udvar-Hazy center, Smithsonian Institution National Air and Space Museum. (Photo by Dane Penland, National Air and Space Museum, Smithsonian Institution)
The Boeing Model 367-80 is on display at the Steven F. Udvar-Hazy Center, Chantilly, Virginia. (Photo by Dane Penland, National Air and Space Museum, Smithsonian Institution) 
Boeing 367–80 N70700 in flight. (Boeing)

© 2017, Bryan R. Swopes

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