This post isn’t so much of a trip report as it is a commentary. The Boeing B 737 is the most successful jet airliner in aviation history, with a total of more than 10’500 aircraft of the type built. It is currently in its fourth generation with the ill-fated B737 Max, the future of which does not look too bright in the wake of the two fatal accidents more than two years ago.
The B 737 was originally built to operate from small airports with limited infrastructure. This meant that the aircraft’s layout required it not to be too high off the ground for better access for the service vehicles and for the possibility to incorporate a set of retractable passenger stairs.
The result was an aircraft with a short, stuby appearance. It is most easily recognisable by the fact that the engines had to be mounted directly under the wing in order to maintain enough clearance to the ground and thus to avoid them becoming contaminated by ingesting debris lying on the ground.
Over the years, the B 737’s fuselage has been stretched a number of times. The wing has also been modified, together with new avionics and more powerful engines. The original B 737-100 was only 29 metres long. Today, the longest version of the type is the B 737-900 at 42 metres.
The B 737-600 is a bit of a squirt, at just 31 metres length. It is also the least successful model of the B 737 series, with only 69 aircraft ever built. Of those 69 aircraft, only about half remain in active service in 2020. Part of the -600’s problem was that it was simply too heavy for the number of passengers it was able to carry, which might also explain why it is the only version of the B 737 for which the manufacturer did not offer the option to have winglets, which would only serve to make the aircraft even more overweight.
SAS was the first and, at one time, the largest operator of the B 737-600, with a fleet of 30 units that were ordered mainly for domestic operations in Sweden. Their intention had been to replace part of their fleet of old DC-9s and MD-80s with the -600. The Scandinavian airline decommissioned its last B 737-600 in 2019.
For the passenger though, the -600 had a lot to offer in terms of comfort, because the cabin of the B 737 in general is much wider than that of other hundred seaters currently in the market, such as the Embraer 195 or the A 220. At least on the -600 there were hardly ever any issues finding a place to store your hand luggage in the overhead bin. As such, it made for a rather pleasant ride on the sector such as Stockholm to Zürich, which has a flight time of slightly more than two hours.
On the face of it, the benefits of having a standard model aircraft for a specific type of mission and then offering it in different models in varying sizes makes a lot of senses, especially in terms of crew training, planning flexibility and maintenance. And for the larger of the B 737 types, that obviously seems to have worked rather well. But the -600 also shows that at the bottom end of the scale, there comes a point where the benefits from having cockpit commonality and sharing parts with other types can no longer make up for the fact that you are, at the end of the day, carrying around with you a lot of dead weight that directly translates in the amount of kerosene you have to upload. That was pretty much the also experience Airbus made with its mini Airbus A 318, of which only 80 were built.