Limited ground clearance
on the 737 led Boeing and
CFM to come up with an
innovative solution to mount
the then new CFM56 engine.
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.
AIRTEAMIMAGES.COM/
MATTHIAS GEIGERABOVE RIGHT • The ‘office’
of a Next Generation 737,
showing the enlarged flat
panel displays that replaced
the CRTs employed on the
Classic series.
RENATO SERRA FONSECA36 AIRLINER WORLD JUNE 2018
BBJ Variants
The initial Boeing Business Jet (BBJ) was
launched in July 1997, combining the 737-700
fuselage with the wing and undercarriage of
the -800. Offering a standard range in the
region of 6,000nm (11,104km) and seating
up to 68 passengers, the type first flew on
September 4, 1998 and the first customer
airframe, for General Electric, was deliveredon November 23 that year. Subsequently, the
BBJ2 was created, based on the -800, and the
BBJ3 on the -900. Interior fit varies accord-
ing to customer, but all BBJs feature integral
airstairs, winglets and additional fuel capacity.
They are certificated for 180-minute ETOPS
as standard. (Photo Aviation Image Network/
Bravo November)The first -500 model completed its
maiden flight less than a year later
and deliveries to launch customer
Southwest Airlines started in February
- A year later, Lufthansa took the
2,000th 737 built, also a -500, while Aer
Lingus had become the first carrier with
-300, -400 and -500 models in service
simulta neously.
The Next Generation
The emergence of the A320 during
the early 1990s posed a serious threat to
Boeing’s market share. The European-
built Airbus, which pioneered the use of
digital fly-by-wire flight control systems
and side-stick controls, had landed
orders from previously loyal 737 cus-
tomers, such as Lufthansa and United
Airlines, leaving the US manufacturer
with little choice but to mount a
response. The company’s board of
directors acted swiftly and initiated a
design study into a new family of
aircraft in 1991, officially launching
the Next Generation (NG) programme
two years later.
Opting to do very little to the fuselage,
the manufacturer combined it with a
bigger, redesigned wing (with optional
winglets) offering greater aerodynamic
efficiency and increased fuel capacity.
For its part, CFM offered the upgraded
CFM56-7, equipped with full-authori-
ty digital engine control (FADEC) and
delivering a baseline thrust rating of
26,400lb (the new engine required
Boeing to enlarge the aircraft’s tailfin to
maintain directional stability).
Cruising at 41,000ft and just under
Mach 0.8, compared with typical
figures of 37,000ft and Mach 0.75 for
the -300/400/500 (since dubbed the
Classic series), the NG had a basic range
of 3,300nm (6,111km), around 800nm
(1,480km) further than its longest-
ranged predecessor. Passenger comfort,
on flights that were now increasingly
medium-haul in length, was improved
with a cabin based on the flex interior of
the Classic, but featuring improvements
adapted from the 777.
NG into Service
Southwest Airlines, already a major
737 operator, placed the NG launch
order on January 19, 1994, committing
to 63 -700s. Its maiden example arrived
in December 1997, barely 10 months
after the type’s first flight.
Next ‘out of the box’ was the -800,
which debuted with Hapag-Lloyd Flug
in April 1998 and has since gone on to
be the best-selling of all the 737 variants.
Conversely, the 110-seat -600 series
(the smallest of the NGs) achieved only
modest sales with production spanning
just 69 examples before Boeing officially
withdrew the variant from its catalogue
in 2012.
The success of the -800 persuaded
Boeing to pursue an even longer
stretch, rising to the challenge posed bythe A321. The 737-900 was launched
in late 1997 on the back of a ten-aircraft
order from Alaska Airlines. Remarkably,
the jet could carry up to 220 passengers,
placing it on a par with the popular but
ageing 757 in terms of capacity if not
range.
Evidently there was potential for a 737
that could replace the older 757
altogether and, buoyed by a 30-strong
order from Lion Air of Indonesia,
Boeing launched such an aircraft, the
-900ER (Extended Range) in 2005,
coinciding with the end of production
for the 757. Powered by the 28,400lb
CFM56-7BE, the -900ER also features
a reworked tailskid, modified leading
and trailing edge surfaces for improved
take-off and landing performance, and
a range of 3,235nm (5,990km).