Tag Archives: Pratt & Whitney Turbo Wasp JT3C

11 March 1957

Aviation, , , , , , , , , , , , , ,
The Boeing 367-80, prototype of the Model 707 airliner, being brepared for taakeoff on teh morning of 11 March 1957, Boeing Field, Seattle, Washington. (Leonard Mccombe/LIFE Magazine)
The Boeing 367-80, N70700, prototype for the Model 707 airliner and KC-135 air tanker, being prepared for takeoff on the morning of 11 March 1957, Boeing Field, Seattle, Washington. (Leonard Mccombe/LIFE Magazine)
Pre-flight inspection at Boeing Field, Seattle, Washington. In the background are newly-built Boeing B-52 Stratofortress bombers. (Leonard Mccombe/LIFE Magazine)
Pre-flight inspection at Boeing Field, Seattle, Washington. In the background are newly-built Boeing B-52 Stratofortress bombers. (Leonard Mccombe/LIFE Magazine)
Tex Johnston checks that the ramp is clear for engine start. Ready to start number one. (Leonard Mccombe/LIFE Magazine)
Tex Johnston checks that the ramp is clear for engine start. Ready to start number one. (Leonard Mccombe/LIFE Magazine)

11 March 1957: The Boeing jet airliner prototype, the Model 367-80, N70700, made a transcontinental demonstration flight from Seattle’s Boeing Field (BFI) to Friendship National Airport (BWI), Baltimore, Maryland. The aircraft commander was Boeing’s Chief of Flight Test, Alvin Melvin (“Tex”) Johnston. Test pilots James Russell (“Jim”) Gannett and Samuel Lewis (“Lew”) Wallick, Jr., completed the flight crew. The flight covered 2,350 miles (3,782 kilometers) and took 3 hours, 48 minutes.

Cruising at 0.86 Mach. (Leonard Mccombe/LIFE Magazine)
Cruising at 0.86 Mach. The four Pratt & Whitney JT3C turbojet engines are turning 100% r.p.m. (Leonard Mccombe/LIFE Magazine)
The flight deck of the Boeing 367-80 during the transcontinental demonstration flight, 11 March 1957. (Leonard Mccombe, LIFE magazine)
The flight deck of the Boeing 367-80 during the transcontinental demonstration flight, 11 March 1957. The flight attendants are (left) Miss Shirlee Mae Adams of American Airlines, and Miss Jo Ann Reeber, Trans World Airways.(Leonard Mccombe/LIFE magazine)
Reporters balance a pen and a coin in the Dash 80's vibration-free cabin. (Leonard Mccombe/LIFE Magazine)
Reporters balance a pen and a coin in the Dash 80’s vibration-free cabin. (Leonard Mccombe/LIFE Magazine)
A news reporter types his story during the transcontinental flight. (Leonatd Mccombe/LIFE Magazine)
A news reporter types his story during the transcontinental flight. (Leonard Mccombe/LIFE Magazine)
Boeing test pilot S.L. "Lew" Wallick updates the chart with the Dash 80's present position. (Leonard Mccombe/LIFE Magazine)
Boeing test pilot Samuel Lewis (“Lew”) Wallick, Jr., updates the chart with the Dash 80’s present position. (Leonard Mccombe/LIFE Magazine)
Flight attendants from Pan American World Airways, American Airlines and Trans World Airlines made up the cabin crew. (Leonard Mccombe/LIFE Magazine)
Flight attendants from three customer airlines made up the cabin crew of the Boeing 367-80. Left to right, they are: Miss Shirlee Mae Adams, American Airlines; Miss Jackee Gibson, Braniff International Airways; and Miss Jo Ann Reeber, Trans World Airways. (Leonard Mccombe/LIFE Magazine)

Jet Airliner Crosses U.S. At Record Clip

Seattle-To-Baltimore Flight Made In 3 Hours, 48 Minutes

WASHINGTON, March 12 (AP) A Boeing 707 jet passenger plane set a new transcontinental speed record for commercial aircraft yesterday, flying the 2,325 miles from Seattle to Baltimore in 3 hours and 48 minutes.

At one point it attained a speed of 698 miles an hour.

A.M. (Tex) Johnston, Boeing chief of flight tests, said he would fly back to Seattle tomorrow with stops at Chicago’s O’Hare Airport and at Denver. He planned a series of local flights for congressmen, Pentagon officials and experts.

The big plane averaged 612 miles an hour for its Puget Sound-to-Chesapeake Bay flight, and sliced 10 minutes off the unofficial transport plane record it set between Seattle and Washington, D.C., in 1955.

There were 52 persons aboard, all but 20 of them newsmen.

‘Jet Stream’ Helps

The 707 left Boeing Field at 10:06 a.m., EST. East of Spokane at 31,000 feet, it hit the “jet stream,” a vast windstream with speeds of up to 125 miles an hour.

These winds enabled the plane to attain supersonic speeds in relation to the ground over northwestern Montana and northern Idaho. However, the plane was actually in subsonic flight and did not break the “sound barrier.”

While in the jet stream, the plane’s peak air speed was 596 miles an hour, but at one point the stream boosted this by 102 miles an hour, for a top speed of 698 in relation to the ground.

Fighter Holds Record

The official transcontinental speed record was set by a one-place F-84F jet fighter two years ago—652½ mph for the 2,446 miles from Los Angeles to New York City. [LCOL Robert R. Scott, USAF, 9 March 1955—TDiA]

The fastest unofficial transcontinental crossing listed by the Defense Department: 715 mph for the 2,700 miles from Riverside, Calif., to Boston last Jan. 25, by a Boeing B-47 bomber.

The 707 is to be delivered to its first airline buyers—Pan American and American—late next year and early in 1959.

The plane’s cost varies from 4½ to 5½ million dollars, depending on size and range, Various models will carry from 120 to 162 passengers.

—Toledo Blade, Tuesday, 12 March 1957, Page 2 at Columns 2–4

Boeing's Chief of Flight Test, Alvin M. "Tex" Johnston updates a memeber of teh cabin crew on the progress of the flight. (Leonard Mccombe/LIFE Magazine)
Boeing’s Chief of Flight Test, Alvin M. “Tex” Johnston, updates a member of the cabin crew, Miss Jackie Gibson of Braniff International Airways, on the progress of the Dash 80’s transcontinental flight. (Leonard Mccombe/LIFE Magazine)
Boeing's Chief of Flight Test guides the Dash 80 to a touchdown on Runway 10, Friendship National Airport, (Leonard Mccombe/LIFE Magazine)
Boeing’s Chief of Flight Test Alvin M. “Tex” Johnston guides the Dash 80 to touchdown on Runway 10, Friendship National Airport, 2:02 p.m., Eastern Standard Time, 11 March 1957. (Leonard Mccombe/LIFE Magazine)
Tex Johnston with flight attendants from Boeing's customers: Pan American World Airways, American Airlines and Trans World Airways. (Leonard Mccombe/LIFE Magazine)
Tex Johnston with three flight attendants from Boeing’s customers: Miss Jackie Gibson, Braniff International Airways; Miss Shirlee Mae Adams, American Airlines; and Miss Jo Ann Reeber, Trans World Airways. (Leonard Mccombe/LIFE Magazine)
Boeing 367-80 N70700 parked at teh international terminal, Friendship National Airport, Baltimore, Maryland. (Leonard Mccombe/LIFE Magazine)
Boeing 367-80 N70700 parked at the international terminal, Friendship National Airport, Baltimore, Maryland. (Leonard Mccombe/LIFE Magazine)
N70700's route of flight, 0706–1102, 11 March 1957. (Leonard Mccombe/LIFE Magazine)
N70700’s route of flight, 0706–1102, 11 March 1957. (Leonard Mccombe/LIFE Magazine)

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-135A 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 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° at 25% chord, and had 7° dihedral. 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). The tail span is 39 feet, 8 inches (12.090 meters). The empty weight of the 367-80 was 75,630 pounds (34,505 kilograms) and the gross weight, 190,000 pounds (86,183 kilograms).

Cutaway scale model of the Boeing 367-80 showing interior arrangement. (Boeing)

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).

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 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.

(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, Smithsonian Institution National Air and Space Museum. (Photo by Dane Penland, National Air and Space Museum, Smithsonian Institution)

Highly recommended: Tex Johnston, Jet-Age Test Pilot, by A.M. “Tex” Johnston with Charles Barton, Smithsonian Books, Washington, D.C., 1991

© 2019, Bryan R. Swopes

22 October 1955

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The first of two Republic YF-105A-1-RE Thunderchief prototypes, 54-098, on Rogers Dry Lake, Edwards Air Force Base, California, 1955. (U.S. Air Force)
Republic Aviation test pilot Russell M. "Rusty" Roth. (Jet Pilot Overseas)
Republic Aviation Corporation test pilot Russell M. “Rusty” Roth. (Jet Pilot Overseas)

22 October 1955: At Edwards Air Force Base, in the high desert of southern California, Republic Aviation Corporation test pilot Russell M. (“Rusty”) Roth took the first of two prototype YF-105A-1-REs, serial number 54-098, for its first flight.

Though equipped with an under-powered Pratt & Whitney J57-P-25 interim engine, the new airplane was able to reach Mach 1.2 in level flight.

Aerodynamic improvements to the engine intakes and redesign of the fuselage to incorporate the drag-reducing “area rule,” along with the more powerful J75-P-5 turbojet engine allowed the production model F-105B to reach Mach 2.15.

The Thunderchief is the largest single-place, single-engine aircraft ever built. It was a Mach 2 fighter-bomber, designed for NATO defensive tactical nuclear strikes with a nuclear bomb carried in an internal bomb bay. The YF-105A was 61 feet, 0 inches (18.593 meters) long, with a wing span of 34 feet, 11 inches (10.643 meters) and overall height of 17 feet, 6 inches (5.334 meters). Its empty weight was 20,454 pounds (9,277 kilograms) and the Maximum Takeoff Weight (MTOW) was 41,500 pounds (18,824 kilograms).

The Pratt & Whitney Turbo Wasp JT3C (J57-P-25) was a two-spool axial-flow turbojet engine with a 16-stage compressor section (9 low- and 7 high-pressure stages) and a 3-stage turbine (1 high- and 2 low-pressure stages). The J57-P-25 had a Normal Power rating of 8,700 pounds of thrust (38.700 kilonewtons), and at Military Power produced 10,200 pounds of thrust (45.372 kilonewtons) (30-minute limit). The Maximum Power rating was 16,000 pounds of thrust (71.172 kilonewtons) with afterburner (5-minute limit). The J57-P-25 was 22 feet, 3.1 inches (6.784 meters) long, 3 feet, 3.8 inches (1.011 meters) in diameter, and weighed 5,120 pounds (2,322 kilograms).

The YF-105A’s wings were swept 45° at 25% chord. The angle of incidence was 0° and there was no twist. The wings had 3° 30′ anhedral. The total wing area was 385 square feet (35.8 square meters).

During testing, the prototype’s maximum speed was 770 knots (886 miles per hour (1,426 kilometers per hour) at 35,000 feet (10,668 meters)—Mach 1.34—and 676 knots (778 miles per hour/1,252 kilometers per hour) at Sea Level—Mach 1.02. The YF-105A’s service ceiling was 52,050 feet (15,865 meters). It’s combat radius was 950 nautical miles (1,093 statute miles/1,759 kilometers), and the maximum ferry range was 2,321 nautical miles (2,671 statute miles/4,298 kilometers).

Repiblic YF-105A 54-098 landing at Edwards Air Force Base. (San Diego Air and Space Museum Archives)
Republic YF-105A 54-098 landing at Edwards Air Force Base. (Ray Wagner Collection, San Diego Air and Space Museum Archives)

The Thunderchief was armed with a General Electric T171E2 (M61) 20 mm six-barrel rotary cannon with 1,030 rounds of ammunition. 8,000 pounds (3,629 kilograms) of bombs could be carried in an internal bomb bay or on external hardpoints. A single free-fall B28IN variable-yield thermonuclear bomb could be carried in the bomb bay.

On 16 December 1955, YF-105A 54-098 made an emergency landing at Edwards AFB after one of its main landing gear assemblies was torn off when it failed to retract during a high speed flight. The pilot, Rusty Roth, was severely injured, but he survived. The prototype was shipped back to Republic for repair, but the cost was determined to be prohibitive.

Though designed for air-to-ground attack missions, F-105s are officially credited with 27.5 victories in air combat.

833 Thunderchiefs were built by Republic between 1955 and 1964. 334 of those were lost to enemy action during the Vietnam War. The F-105 remained in service with the United States Air Force until 1980, and with a few Air National Guard units until 1983.

Republic F-105D-5-RE Thunderchief 58-1173 carrying a bomb load of sixteen 750-pound M117 general purpose bombs. (U.S. Air Force)
Republic F-105D-5-RE Thunderchief 58-1173 carrying a bomb load of sixteen 750-pound M117 general purpose bombs. (U.S. Air Force)

© 2018, Bryan R. Swopes

15 July 1954

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

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.

At 130 miles per hour (209 kilometers per hour), the Boeing Model 367–80 (“Dash Eighty”) lifts off at Renton Municipal Airport on its first flight, 15 July 1954. (Boeing Images)

Tex Johnston wrote about the first flight of the “Dash Eighty” in his autobiography:

     We completed our before-takeoff checklist, Dix worked the tower, and we were cleared for takeoff. I called the theodolite station: “Dash 80, Johnston, stand by, brake release on the count of three.” At full throttle, the four Pratt and Whitney engines at 100-percent power, tail-pipe temperatures and oil pressure on the money, I said, “One, two, three,” and released the brakes. The airplane leaped forward and accelerated rapidly. We obviously would be airborne by midfield. As airspeed passed the calculated V1 speed, I applied back elevator. The nose lifted off. Dix called 130 mph, and we were airborne.

The Boeing Model 367–80 (“Dash Eighty”) takes of from Renton Field on its first flight, 15 July 1954. (Boeing Images)

     Eyeballing the airspeed, I continued to increase the climb angle to avoid exceeding the flap-down placard limit of 225 mph. We were at 1,200 feet as we climbed past end of the runway. Dix commented, “Is this thing going to climb straight up?” Over Lake Washington, I throttled back to climb power, sure that the spectators had never before witnessed takeoff performance and climb attitude like that. . . .

—Tex Johnston: Jet-Age Test Pilot, by A.M. “Tex” Johnston and Charles Barton. Smithsonian Books, Washington, D.C., Chapter 15, Pages 542–543.

The prototype Boeing 367-80, N70700, climbs out at Renton Field, 15 July 1954. (Boeing Images)

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.”

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, the first successful jet airliner. Though they look very similar, the 707 is structurally different than the KC-135 and has a wider fuselage.

Boeing Aircraft Co. President Bill Allen talks to test pilots Tex Johnston and Dix Loesch after first flight of the Model-367-80 prototype. (Seattle Post-Intelligencer)

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 Model 367-80 (“Dash Eighty”) in flight. (Joe Parke/Wikipedia)

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).

Boeing 367-80 N70700, photographed during its first flight, 15 July 1954. (The Boeing Company)
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)

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) 

© 2020, Bryan R. Swopes

14 May 1954

Aviation, , , , , , , , , , ,
Boeing 367-80 N70700 is rolled out of teh final assembly building at Boeing's facility at Renton Field, 14 may 1954. (Boeing)
Boeing 367-80 N70700 is rolled out of the final assembly building at Boeing’s facility at Renton Field, 14 May 1954. (Boeing)

14 May 1954: The Boeing Model 367-80 prototype, N70700, was rolled out at the Boeing plant at Renton Field, south of Seattle, Washington. Boeing’s founder, William Edward Boeing (1881–1956) was present. The prototype made its first flight 15 July 1954 with Boeing test pilots Alvin M. “Tex” Johnston and Richard L. “Dix” Loesch. It is painted yellow and brown.

Originally planned as a turbojet-powered development of the Boeing KC-97 Stratotanker, the Model 367, the 367-80 was the 80th major design revision. It is called the “Dash 80.”

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-135A 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.

Cutaway scale model of the Boeing 367-80 showing interior arrangement. The woman on the right is Gloria Durnell, a secretary at Boeing. (Boeing)

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° at 25% chord, and had 7° dihedral. 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). The tail span is 39 feet, 8 inches (12.090 meters). The empty weight of the 367-80 was 75,630 pounds (34,505 kilograms) and the gross weight, 190,000 pounds (86,183 kilograms).

Boeing 367-80 N70700. (San Diego Air & Space Museum Archives)

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).

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.

Boeing 367-80, N70700, in storage. (San Diego Air & 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, Smithsonian Institution National Air and Space Museum. (Photo by Dane Penland, National Air and Space Museum, Smithsonian Institution)

Highly recommended: Tex Johnston, Jet-Age Test Pilot, by A.M. “Tex” Johnston with Charles Barton, Smithsonian Books, Washington, D.C., 1991

© 2019, Bryan R. Swopes