The CFM56 engine offered
significant improvements
over the original JT8D,
but had a far larger diam-
eter, so it could not be
conventionally mounted to
the aircraft without exten-
sive modifications to the
wing and undercarriage.
AIRTEAMIMAGES.COM/
JORGEN SYVERSENABOVE LEFT • Many Classics
have been given a new
lease of life as freighters.
This ASL Airlines Belgium
example, OE-IAG (c/n 25168),
was delivered new to
Dan-Air in 1992.
AIRTEAMIMAGES.COM/
RUDI BOIGELOTThe -400 series was
intended to plug the gap
between the existing 737-
300 and the 240-seat 757.
AIRTEAMIMAGES.COM/
DANIJEL JOVANOVIC34 AIRLINER WORLD JUNE 2018Milestone Jets
Variant Customer Delivered
First airline delivery 737-100 Lufthansa December 28, 1967
1,000 737-200 Delta Air Lines December 22, 1983
2,000 737-500 Lufthansa February 25, 1991
3,000 737-400 Alaska Airlines February 27, 1998
4,000 737-800 Air Algérie June 19, 2001
5,000 737-700 Southwest Airlines February 13, 2006
6,000 737-800 Norwegian April 16, 2009
7,000 737-800 flydubai December 16, 2011
8,000 737-900ER United Airlines February 16, 2014
9,000 737-800 China United Airlines April 21, 2016
10,000 737 MAX 8 Southwest Airlines March 30, 2018applications had been restricted to
widebody aircraft. It was not until 1974
that CFM International – a joint venture
between General Electric and
France’s Société Nationale d’Etudes et
Construction de Moteurs d’Aviation
(SNECMA) – pooled its parents’
research into small-fan, high-bypass
engines. The resulting CFM56 ran for
the first time on June 20, 1974 and won
its first application in United’s DC-8-60
re-engine programme.
With the new turbofan proving itself
in service, Boeing began design work
on a CFM56-powered 737-upgrade –
the -300 series. Using a tried and tested
concept, the latest variant would be
a linear evolution of its predecessors,
sharing a 70% commonality with the
earlier -200 but incorporating extended
wing tips and an 8ft 8in (2.68m) fuse-
lage stretch, providing space for up to
14 9 passengers.
The 737-300 was given the official
go-ahead in March 1981, following a
ten-aircraft, plus options, launch order
from USAir and Southwest.
The cornerstone of this upgraded
design was the CFM56, but the change
of powerplant brought mixed blessings.
It offered significant improvements
over the original JT8D, but had a far
larger diameter, so it could not be
conventionally mounted to the aircraft
without extensive modifications to the
wing and undercarriage.
Keen to avoid a costly redesign,
Boeing worked with CFM and devised
an unusual solution – the intake fan
diameter was reduced, while several
components were relocated from
beneath the engine to the sides,
giving the nacelle a unique, flattened
appearance.
Furthermore, the 20,100lb-rated
CFM56-3B1 was positioned in front of
the wing rather than underneath it and
this, along with a slightly lengthened
nose wheel, provided the necessary
ground clearance.Second Generation
Takes Flight
The prototype 737-300, c/n 22950, was
rolled out at Boeing’s Renton plant on
January 17, 1984 and made its maiden
flight under the command of Jim
McRoberts on February 24. The jet was
the 1,001st 737 to be built and carried the
same registration as the first -100 series,
N73700, a theme that would continue
across all the ‘new generation’ models.
It was joined by a further two examples
for the nine-month certification
programme.
USAir took the first customer aircraft
on November 28, 1984, two weeks
after FAA certification was granted.
Southwest received its initial aircraft
two days later and deliveries continued
rapidly– with orders flooding in. In
Europe, British leisure carrier Orion
Airways became the first export
customer for the type when it took
delivery of its maiden example on
January 29, 1985.