Lost Classics - Boeing 2707-200 SST
commercial jet transports began to enter service after World War 2, aiming for
a supersonic airliner was a remote dream, until Convair developed their Mach 2
B-58 bomber. The dreams revived. Some studies proposed a B-28-like aircraft with
a detachable passenger pod slung below it. Britain set up the Supersonic Transport
Aircraft Committee in 1956, and in 1959 they favoured two main types of SST (supersonic
transport). One was a radical Mach 1.2 transport with a double-kinked M-shaped
wing plan, and the other was a longer range, larger Mach 1.8 aircraft, a slender
These designs were considered to be about as far as such an aircraft could go
with a traditional aluminium-alloy airframe. In the USA, steel sandwich structures
were already being used. The XB-70 Valkyrie would
use stainless steel, and the A-12 Blackbird
When it became clear, from 1962, that the Anglo-French SST, to be named Concorde,
would actually go ahead, other nations began to work on designs of their own.
In the USSR, the Tupolev design bureau began working on their Tu-144. America
could hardly stand by, and in 1962 NASA began the SCAT (Supersonic Commercial
Air Transport) program.
The SST program gained impetus when, in a speech delivered on 5th June, 1963,
President John F. Kennedy announced that such a program was authorised. The Federal
Aviation Authority issued a Request for Proposals for an SST design to three airframe
and three engine manufacturers - Boeing, Lockheed, North American, Curtiss Wright,
General Electric and Pratt & Whitney. The designs were submitted to the FAA
on January 15th, 1964.
Unlike everyone else, the Americans would aim for a Mach 3 (2,000 mph) airframe
of steel or titanium.
had quietly worked on a concept for an SST aircraft since 1952, as part of the
project work which goes with corporate forward-thinking. In 1958 they had set
up a small group to concentrate entirely on developing an SST design, and by 1960
were spending over $1m annually on it. Using Boeing Model no. 733, they came up
with a few alternative proposals.
Most of their options involved delta-wing designs. The work of another Boeing
team on a design for a TFX tactical fighter with variable sweep wings (later to
be shelved in favour of the the General Dynamics F-111) drew their attention to
the benefits of a variable geometry.
During 1960 a "competition" was held within the Boeing SST group between
the delta and variable-sweep configurations, looking to a 150-seat aircraft capable
of non-stop flight between Western Europe and the Eastern US. The variable sweep
option emerged substantially ahead.
This was the design which Boeing submitted to the FAA for evaluation against the
delta design of Lockheed's L-2000. A tentative Model 2707 was used to designate
the design, but mostly Boeing simply called it their "1966 model". It
was submitted to the FAA in early 1964 as the Model 733-197. The FAA initiated
further studies of proposals submitted by Boeing, Lockheed, GE and P&W, the
results of which were submitted that November. By now Boeing's design had become
the Model 733-290, with 250 seats.
Final design submissions were next sought by the FAA, and Boeing produced the
733-390, with a capacity for up to 300 passengers. By the final phase, in September
1966, Boeing was working with an even larger design, for up to 300 passengers.
They had built a mock-up of the aircraft by now. It was the last day of 1966 when
the final design was chosen. It was the Boeing design.
The mock-up of the variable-geometry aircraft was 306 feet long (91.8 m.). It
showed both Pratt & Whitney JTF17A and General Electric GE4/J5 engine pods,
with the latter being selected by the FAA for development along with the Boeing
The wings on the mock-up could be moved, manually from fully aft, with a 72°
;eading edge sweep, to fully extended, with a 30° sweep. A design modification
brought the forward sweep forward to 20° for better take-off and landing performance.
A benefit of variable geometry was, of course, the ability to take off and land
at lower speeds and in less distance than would a comparable fixed wing aircraft.
was to be seven abreast, two seats each side with three in the centre, and two
aisles. The mock-up was fitted with 277 seats (30 first-class and 247 tourist).
The impression on entering the cabin was that the so-called "narrow"
part of the fuselage was noticably wider (about 4 ft or 1.22 m) than any contemporary
jet transport. The cabin length was interrupted by two galley/toilet areas. Wardrobe
racks, galley tray containers and bar units could be removed from stowed positions
and wheeled up and down aisles. Overhead luggage racks included restrainers, and
were capable of housing items which usually had to be stowed under passengers'
Boeing mocked up two possible forms of inflight entertainment; retractable TV
screens in the overhead luggage racks at every sixth row, or small permanent screens
in consoles between the paired first-class seats. Windows had an external diameter
of only 6 inches, but the 12 inch internal diameter gave an illusion of size.
Rather than sun blinds, Boeing proposed a rotatable inner panel of polarised glass.
Seats were the company's own design, and claimed to adjust to adults up to 6 ft.
7 in. (2.0 m) tall. In addition to underfloor holds, there was a large baggage
compartment to the rear of each cabin.
the Concorde the SST had a variable nose geometry to improve flight deck
forward views on approach. Boeing used a double-hinge, with the section forward
of the cockpit angling down but the nose cone maintaining a similar axis to that
of the fuselage. With the nose raised, minimum ground clearance was 8 ft. 9 in
(2.67 m), reducing to only 4 feet (1.22 m) with it lowered.
Boeing predicted that if design and construction of prototypes began in early
1967, the first flight could be made in early 1970. Design and fabrication of
production aircraft could begin in early 1969 with the flight testing in late
1972. The first aircraft could then be certified and introduced to airline service
in mid-1974. By 1980 the company estimated there would be a market for a larger
Model 390-475 SST, with between 700 and 1,000 aircraft being required.
The Boeing variable-geometry SST dream was never realised. The variable-sweep
idea was abandoned in October 1968, and the 2707-300 was cut to 234 seats, with
a fixed gull wing mounted ahead of a horizontal tail. It used essentially the
same fuselage and engines as the preceding version.
prototypes were begun in September 1969 but, amid a general US protest against
Concorde, the US Senate closed down the SST program completely on 24th
March, 1971, possibly the first time the US had backed away from a potentially
The Russian Tu-144 entered cargo service in 1975, despite the crash of the second
pre-production aircraft in Paris in 1973. After another accident production ceased
in June 1978. The Concorde first flew on 2nd March, 1969. It entered service
between London, Paris, Bahrain, and Rio/Dakar. The obvious destination, New York,
refused to admit the foreign SST until 24th May, 1976.
|Boeing SST data:
Four General Electric GE4/J5P turbojets,
each of 63,200 lb. st (28677
EMPTY OPERATING WEIGHT
287,500 lb (130308 kg)
MAX. RAMP WEIGHT:
675,000 lb (306175 kg)
MAX. LANDING WEIGHT:
430,000 lb (195045 kg)
75,000 lb (34020 kg)
NORMAL CRUISING SPEED:
Mach 2.7 1,800 mph (2900 km/h)
at 64,000 ft / 21000m
4,250 mls (6840 km)
with 277 passengers
5,700 ft (1870 m)
6,500 ft (2133 m)
180 ft 4 in (54.97 m) spread,
105 ft 9 in (32.23 m) swept.
306 ft 0 in (93.27 m)
46 ft 3 in (14.1 m)
FUSELAGE MAX. EXTERNAL DIMENSIONS:
Width 16 ft 8 in (5.08 m),
depth 15 ft 7 in