T
he jet age began in earnest when
Britain’s four-engined de Havilland
Comet 4, followed by the Boeing
707, began ying across the Atlantic
in 1958. These aircraft shrank the world,
but it wasn’t just long-haul destinations that
would feel the bene t of the revolutionary
new powerplants.
The need for a short-haul ‘bus stop’ jet
to serve smaller airports was apparent from
the start of this new age, but at Boeing in the
mid-1950s, every engineer was working at
out to create the 707.
Once the big airliner was up and running
( rst ight on December 20, 1957, and in
service with Pan Am on October 26, 1958),
the company was able to create a short-haul
stopgap with the 720. This was a smaller,
lighter 707 optimised for short trips and
runways, which rst ew on November 23,
1959, and went into service on July 5, 1960.
Despite the 720’s interim nature, Boeing sold
154 examples, many of which remained in
service well into the 1980s, demonstrating
the size of the market for a local jet, and the
quality of Boeing’s products.A ‘bus stop’ jet needed to have structural
strength to sustain a high frequency of take-
offs and landings, and be capable of being
shoehorned into short runways, so a robust
airframe and excellent low-speed handling
was essential. The 720 was a reasonable
impersonator, but the market needed a
bespoke solution. By 1957, 40 engineers were
already hard at work on the machine that
would become the 727.DEMANDING SPECIFICATIONS
The initial objective was for a gross weight of
135,000lb (61,235kg) and the ability to take
off from a 5,000ft (1,524m) runway without
a weight penalty (which would be having to
leave payload behind). A small and lightweight
wing would not be able to deliver that kind
of performance, so that rst signi cant year
for the programme was spent on low-speed
aerodynamic research and development.
This was necessary to achieve the most
impressive lift coefficient with a minimum of
structural weight and mechanical complexity.
Likely customers were canvassed for their
preferences. United Airlines was keen on afour-engined machine to ensure performance
at its Mile High hub at Denver. Eastern Airlines
wanted at least three engines for its overwater
ights to the Caribbean islands, since twins
in those days were limited to routings that did
not venture more than 60 minutes from land.
And domestic-only American Airlines was
happy with a twin.
In Britain, de Havilland had settled on a
three-engined con guration with a high ‘T-tail’
at the end of the 1950s for its Trident jetliner.
Lord Douglas of Kirtleside, chairman of
British European Airways, the Trident’s main
customer, suggested Boeing and de Havilland
collaborate to create a single design.
This spurred the development of the 727
as the Trident proposal was ahead of the
pack (indeed, it beat the 727 into the air by
more than a year). Boeing was given access
to de Havilland’s technical data regarding the
placement of an engine in the tail, and the
structure and aerodynamics of a high ‘T-tail’.
With design studies affirmed by their
brush with the British, the 727 improved on its
competitor – bigger, heavier, more powerful,
with far more range and much better runway62 Aviation News incorporating Jets November 2018
BOEING 727The sleek and
distinctive 727
jetliner was at the
forefront of short-haul
aircraft design.
Charles Kennedy
reviews the type’s
development and
operational service.