Boeing continues to ramp up
production of the 737 family.
This year the Renton plant
is increasing output from 47
aircraft per month to 52, a
figure set to rise to a record
high of 57 in 2019.
BOEINGThe 110-seat 737-600 was
the smallest of the Next
Generation series and
achieved only modest
sales. Production spanned
just 69 examples before
Boeing officially withdrew
the variant from its
catalogue in 2012.
AVIATION IMAGE NETWORK /
BAILEYThe -800 entered service
in April 1998 and has since
gone on to be the most
popular of all the 737
variants, accounting for
almost half of the 10,000
examples produced to date.
AIRTEAMIMAGES.COM/
SIMONE CIARALLIhttp://www.airlinerworld.com 35A Long Stretch...
In its -300 application, the CFM56-
3B1 delivered 20,100lb of thrust, but the
basic engine was capable of consider-
ably higher ratings. Boeing took this
flexibility and combined it with various
fuselage lengths to produce 737
derivatives suitable for routes and
passenger loads never-before envisaged
for the type.
Developing an even longer airframe
was something of a gamble for Boeing.
The US manufacturer was eager to plug
the gap between the existing family
and the 240-seat 757, but such a move
would pitch it directly against the A320.
Undeterred, Boeing pressed ahead
with the series -400, incorporating
a 10ft (3m) fuselage extension and
pushing seating capacity up to 170 in
an Economy layout. Other changes
included strengthened wings and
undercarriage to cope with take-off
weights up to 150,000lb (68,039kg),
along with installation of a tail bumper,
considered necessary because of the
longer fuselage and the increased risk of
tail scrape on rotation.The most notable difference on the
latest variant was the now standard
glass cockpit, with Boeing having
bowed to increasing customer pressure
to offer the 737 with at least some com-
monality to its larger siblings. The first- 4 00 was officially unveiled on January
26, 1988 with McRoberts again com-
manding the first flight on February 19.
...and a Shrink
Sales of the new-generation models
were brisk, but for some existing 737-
200 operators looking to upgrade, the
stretched fuselage and additional
capacity was too much. Thus, the -500
series was born – Boeing’s newest
offering combined the best features
of the latest models with a 102ft (31m)
fuselage, just 1ft 7in (48cm) longer than
the -200 it was intended to replace and,
in an effort to attract repeat
business, customers were given the
option of keeping analogue gauges in
place of the new glass cockpit.
The now standard CFM56 engine was
retained, though there was a choice of
the -3B1 variant from the 737-300 or the
de-rated, 18,500lb -3B4 variant,
both of which were 25% more efficient
than the JT8D-9 turbofans they
replaced. By the time production of the
-200 series was concluded and the final
example, 737-25C, B-2524 (c/n 24236)
was delivered to Xiamen Airlines in
August 1988, its long-term successor
was poised to take over.The^
Sound of
Silence
The launch of the 737-300/-400/-500 models
by Boeing proved to be well timed. The
Aviation Noise and Capacity Enhancement
Act, imposed by the US Government in 1990,
had a significant impact on the original JT9D-
powered 737 when it set out to regulate
aircraft noise by mandating the introduction
of Stage 3 noise suppression technology on
all aircraft by 2000. Carriers were faced with
the choice of buying new, compliant aircraft
or reducing the noise of their existing fleets,
creating a large market for ‘hush kits’. The
equipment, which could be retrofitted to the
engines of ageing 737-100s and -200s, would
bring the aircraft within the Stage 3 require-
ments, but they were still significantly noisier
than the new-generation models. However,
with legislation becoming increasingly
stringent and the hush kit-equipped jets
consuming almost 50% more fuel than their
new-build counterparts during take-off alone,
the majority of early-model 737s were
effectively forced out of Europe and the US.