AP 118 · No. 11 Section II · Aircraft Plate 276 / 370

Plate 276 of 370 · Early jet age · Jet transport prototype

Boeing 367-80

367-80 ‘Dash 80’ N70700, painted as The Boeing 367-80 N70700, the ‘Dash 80’, the only one built: Boeing’s private-venture jet transport prototype, first flown from Renton on 15 July 1954, which led to both the KC-135 tanker and the 707 airliner, was barrel-rolled over Lake Washington by Tex Johnston in August 1955, and has been displayed since 2003 at the Smithsonian’s Steven F. Udvar-Hazy Center, Chantilly, Virginia: a four-engined jet transport with a slim circular-section fuselage narrower than the 707’s, a low wing swept at 35 degrees carrying four Pratt & Whitney JT3C turbojets in pods on forward-swept pylons, a swept fin and tailplane and a tricycle undercarriage with four-wheeled main bogies, shown standing level with the gear down: Boeing’s house colours, with a yellow crown, fin and rudder, a thin white stripe over a chocolate-brown cheat line carrying five round windows and running forward over the nose, a yellow tongue over the cockpit roof, a white lower fuselage, ‘BOEING’ on the crown and the cheat line, ‘BOEING 707’ and ‘N70700’ on the fin, brown engine cowls with Pratt & Whitney badges and natural-metal wings, tailplane and pylons, as photographed at Udvar-Hazy (no 367-80 is in a UK museum; no three-view of the Dash 80 was found, so the side view is fitted to a near side-on photograph of N70700 and the wing, tailplane and engine pods follow a KC-135A three-view, rescaled to the Dash 80’s published span and length; the intake covers it wore outdoors are left off).

3D model

Turn it over

A procedural model built in Blender from published dimensions, drawings and photographs, painted as The Boeing 367-80 N70700, the ‘Dash 80’, the only one built: Boeing’s private-venture jet transport prototype, first flown from Renton on 15 July 1954, which led to both the KC-135 tanker and the 707 airliner, was barrel-rolled over Lake Washington by Tex Johnston in August 1955, and has been displayed since 2003 at the Smithsonian’s Steven F. Udvar-Hazy Center, Chantilly, Virginia: a four-engined jet transport with a slim circular-section fuselage narrower than the 707’s, a low wing swept at 35 degrees carrying four Pratt & Whitney JT3C turbojets in pods on forward-swept pylons, a swept fin and tailplane and a tricycle undercarriage with four-wheeled main bogies, shown standing level with the gear down: Boeing’s house colours, with a yellow crown, fin and rudder, a thin white stripe over a chocolate-brown cheat line carrying five round windows and running forward over the nose, a yellow tongue over the cockpit roof, a white lower fuselage, ‘BOEING’ on the crown and the cheat line, ‘BOEING 707’ and ‘N70700’ on the fin, brown engine cowls with Pratt & Whitney badges and natural-metal wings, tailplane and pylons, as photographed at Udvar-Hazy (no 367-80 is in a UK museum; no three-view of the Dash 80 was found, so the side view is fitted to a near side-on photograph of N70700 and the wing, tailplane and engine pods follow a KC-135A three-view, rescaled to the Dash 80’s published span and length; the intake covers it wore outdoors are left off). Drag to orbit, scroll or pinch to zoom · download .glb (1.5 MB)

Data plate

Specification

First flight, number built and top speed are for the whole family (‘Dash 80’, prototype of the 707 and KC-135); engine, crew and dimensions are for the 367-80 ‘Dash 80’ N70700 modelled here.

History

The 367-80 ‘Dash 80’

In 1952 Boeing had built big jets for the US Air Force, the B-47 and the B-52, but no jet transport, and neither the airlines nor the Air Force had asked for one. De Havilland’s Comet was already flying passengers. Boeing’s president, Bill Allen, decided to gamble about $16 million of the company’s own money, much of its net worth, on a prototype that could be sold both as a jet tanker and as an airliner. To hide it from competitors it was given the number of an old piston-engined transport project, Model 367-80, and inside Boeing it was always the ‘Dash 80’.

It had a 35-degree swept wing like the bombers’, four Pratt & Whitney JT3 turbojets in pods slung on pylons ahead of the wing, and a fuselage 132 in wide. The Dash 80 was rolled out at Renton on 15 May 1954 and first flew on 15 July, with Tex Johnston and Dix Loesch at the controls. In August 1955, over Lake Washington during the Seattle Seafair hydroplane races, Johnston rolled it twice in front of a crowd that included airline chiefs, to show how strong and well-mannered it was. Allen was not amused, but the point was made.

The Air Force ordered a tanker version, the KC-135, in 1954, with a fuselage 12 in wider, and in October 1955 Pan American ordered the 707 airliner, widened again so that it could seat six abreast. The Dash 80 itself stayed with Boeing as a flying test-bed, trying out wing and flap designs, a fifth engine on the rear fuselage for the 727 and a host of other systems, until it was retired in January 1970. Boeing gave it to the Smithsonian in 1972, restored it in the 1990s, and in August 2003 it made its last flight, to Washington Dulles, for the Udvar-Hazy Center. It is the only one built, and it is not in a UK museum.

This airframe

367-80 N70700 ‘Dash 80’

N70700The airframe modelled

N70700 is the one and only 367-80, completed at Renton in 1954 and flown as Boeing’s prototype and test aircraft until January 1970. After years in store in the Arizona desert it went to the Smithsonian, came back to Boeing in 1990 for restoration and flew again, and on 27 August 2003 it made its last flight, from Seattle to Washington Dulles. It is displayed in the Boeing Aviation Hangar of the Smithsonian’s Steven F. Udvar-Hazy Center, Chantilly, Virginia. The model shows it as it stands there in Boeing’s house colours: a yellow crown, fin and rudder, a thin white stripe over a chocolate-brown cheat line that runs forward over the nose and carries five round windows, a yellow tongue over the cockpit roof, a white lower fuselage, ‘BOEING’ on the crown and the cheat line, ‘BOEING 707’ and ‘N70700’ on the fin, brown engine cowls with Pratt & Whitney badges, and natural-metal wings, tailplane and pylons. No three-view of the Dash 80 was found, so its side view is fitted to a near side-on photograph of N70700, and the wing, tailplane and engine pods follow a KC-135A three-view rescaled to the Dash 80’s published span and length; the intake covers it wore outdoors are left off.

Where to see one

Not on charge

The only one built, N70700, is at the Smithsonian’s Udvar-Hazy Center by Washington Dulles.

All 370 plates

Profiles and models are procedural interpretations built in Blender from published dimensions, three-view drawings and photographs of each airframe. Treat the museum aircraft as the reference.