The 737 was designed
around the same, six-
abreast cabin and forward
fuselage of the 727, which
itself was similar to the
four-engined 707. Seating
capacity was, however,
quickly increased from the
original 50-60 to 100 for the
-100 series, and 112 for the
stretched 737-200.
KEY COLLECTION/BOEINGhttp://www.airlinerworld.com 31Two’s Company, Three’s a Crowd
Sales of the original 737 series were
relatively slow, particularly in the US.
This was due in part to design decisions
that led to considerable controversy
between the pilots, the airlines,
and the FAA who would be certifying
the aircraft.
At the time the twinjet was launched,
legislation dictated that only aircraft
with a maximum take-off weight of
80,000lb (36,287kg) could be oper-
ated by a two-man crew. It was these
rules that dictated the size of the
first Douglas DC-9s, while the BAC
One-Elevens acquired by Braniff and
American Airlines also met this crite-
rion. So too did the 737 in its original
guise, but with potential customers
demanding a bigger aircraft, its weight
crept up from the initial 79,000lb(35,834kg) to 93,000lb (42,184kg). As
a result, the jet – designed for just two
pilots and lacking a flight engineer’s
station – legally required a third crew
member, making it a decidedly expen-
sive proposition.
In April 1965, the FAA moved to abolish
the weight limit criteria, but two years
of deliberation and consultations
followed between pilots’ unions, airline
managers and airframe manufacturers.
The authority eventually launched a
series of trials in 1967, flying the 737
on airline-style services on the busy
Boston-New York-Washington corridor
with a two-man crew. As a result of
these tests, the FAA declared: “The far-
reaching evaluation of the Boeing 737
was started in September 1965, with
the evaluation of the cockpit mock-up.Continuous evaluations over the past
two years included regular operations
of the aircraft in a high-density air traf-
fic environment to determine workload,
complexity, and safety of operations in
a fail-safe concept. These flights were
part of a very extensive flight-testing
programme accomplished by the FAA
and Boeing personnel. The technical
findings coming out of these evalua-
tions are that the aircraft can be safely
flown with a minimum of two pilots.”
The 737 was subsequently certified
in December 1967, though several
operators – including Western Airlines,
Frontier, Wien Air Alaska and United –
were bound by labour agreements with
the unions to fly with a crew of three.
The latter did not revert to two-pilot
737 operations until 1981.airline threatened to walk away unless
the manufacturer made a firm com-
mitment to build the type it was on the
back of this, and a 21-aircraft launch
order, that the programme was officially
launched on February 15, 1965.
Though significant, Lufthansa’s order
was not particularly large despite the
aircraft having been designed to the
airline’s exacting specifications. In par-
ticular, it had been given seating capac-
ity for 100 passengers, as opposed to the
50 -60 seats that formed the basis of the
original design. Despite the increased
size, neither Eastern nor United felt the
737 met their future capacity require-
ments. Boeing immediately offered
the -200 series, a stretched variant that
incorporated a 193cm (76in) fuselage
extension and increased seating to 112
- sufficient to attract a 40-aircraft order
from United.
Airborne
Design and production of the first six
prototypes began in earnest during the
spring of 1965. Of immediate concern
to Boeing was the simultaneous devel-
opment of both the -100 and -200
series, particularly given the low
number of orders at that time. Savings
were gained in tooling, design, man-
hours and workforce training by
building the 737 around the same, six-
abreast fuselage and nose design of the
727, which itself was similar to the 707.
With the manufacturer’s facility at
Renton, Washington already busy with
the 707 and 727, the 737 was initially
assembled at nearby Boeing Field/King
County (the production line was moved
to Renton in 1970, after 271 airframes
were completed).
It was here that prototype N73700
(c/n 19437) was officially rolled out in
December 1966. Adorned with Boeing’s
distinctive yellow and brown house
livery, the jet departed from Boeing Field
on its maiden flight on April 9, 1967 in
the hands of test pilots Brian Wygle and
Len Lewick. The successful two-and-a-
half-hour sortie ended at another of
the company’s facilities, nearby Paine
Field, Everett, marking the start of a
1,300-hour, six-aircraft certification
programme.Testing Times
By the time the prototype had taken
flight, the first production example
for launch customer Lufthansa was
nearing completion, leading Boeing
to believe it would meet its optimistic
deadline of putting the aircraft into
service by the end of the year.
However, early testing identified a
problem that was significant enough for
the manufacturer to announce a three-
month delay on deliveries. Boeing
found the airframe produced excess
drag at high cruise speeds, putting the
new, lower-weight wing spars at risk
of buckling at a loading of just 34%