The 737 has been a great success story for Boeing as its best selling line of
commercial jets to date. In production for over 50 years,
it has been continuously modified and updated through many variants. Let’s examine the main
differences through the four 737 families – the Original, Classic, Next Generation, and MAX.
The “Original” Boeing 737 was introduced in 1967.
Only 60 737-100 aircraft were sold, and it was soon improved with the 737-200.
This offered an extended fuselage, requested initially by United Airlines,
and proved much popular (with 1,095 sales). There was also a 737-200 Advanced version,
with improved aerodynamics, more powerful engines, and higher fuel capacity and range.
Other modifications were made to suit airline demand, including a Combi version
for partial freight use, and the provision of an ‘Unpaved Strip Kit’ to land on gravel runways.
Moving on, production of the ‘Classic’ series started with the -300 in 1984. The aim was a
transformation focussed on increased capacity and better fuel efficiency. The family would
be modified but keep commonality with earlier models, in both design and flight operation.
The main difference was new engines, employing CFM56 turbofan engines,
increasing thrust. However, a larger engine diameter, and low ground clearance meant
engines were placed ahead of the wing rather than directly under. The bottom of the engine housing
was also flattened for sufficient clearance. The -300’s extended fuselage offered a small
increase in capacity -up to a maximum of 149 compared to -200’s 136. The classic series
also featured an increased wingspan, tailfin redesign, and severa cabin improvements.
The 737-400 continued the stretching,
growing the -300 around three meters, increasing the capacity to 188.
The -500 was actually a smaller model, going back to the size and capacity of the 737-200.
The Next Generation (NG) series was launched in 1993 and first flew in 1997. This came
about mainly to address rising fuel prices and growing competition from the Airbus A320 family.
The series offered several improvements including better fuel efficiency,
extended range, and larger capacity variants (up to 215 passengers).
This was achieved with newer engines and a redesigned wing and cockpit.
Here are the capacities and ranges of each Next Generation variant:
As it stands, the -800 has become Boeing’s best-selling 737 model,
offering an excellent balance of range and capacity.
The fourth generation of the 737 family was launched in 2011 as the MAX series,
meant to compete with the Airbus A320neo family. Offering new CFM International LEAP engines
and distinctive winglets, the MAX would offer more gains in range and efficiency.
Let’s look at the various models and their capacities and range:
It should be noted that for the MAX 8 to carry as many as 200 passengers would require
modification to a special sub-variant, which includes an additional exit door.
The 737 MAX, of course, has suffered from its grounding in 2019 following two crashes.
There have been several cancellations over the last year, but with recertification granted in
several key markets in recent months, the 737 should regain some of its popularity.
Do you have a favorite 737 model? Let us know which one, and why by leaving a comment?