Built to do battle with the Airbus A321, the 737-900 is the longest 737 ever created and was the final model for the company’s 737 Next Generation Range of the 1990’s. However, despite all this effort, the ambiguous -900 was, at first, a sales calamity, thanks in no small part to some questionable engineering choices by Boeing itself.
The 737-900 is essentially a complete step-up from the preceding 737-800, sharing a majority of its features; including engines, electronics and configuration. However, the main change involved with this aircraft is the lengthening of the fuselage by 7ft 10 inches, giving it an overall length of 138ft 3 inches. This makes it 40cm longer than the smallest version of the Boeing 707; the 707-120. As a result, the -900 has 9% more cabin floor space and 18% more cargo space than the -800.
However, its commonality with the 737-800 has been something of an Achilles Heel to this otherwise promising aircraft. Because the 737-900 is fitted with the same layout of over-wing emergency exits and 4 main exit doors as the 737-800, the configuration requires a restriction of 189 passengers in order to allow proper access to the exits in the event of an emergency. This means that overall space, which could seat in excess of 190 passengers, is not fully utilised.
There are more problems too. While the aircraft is longer than the -800 and shares the same take-off weight and fuel capacity, the increased size and overall weight means its range is only increased over the -800 by about 30nmi.
The project was officially launched in April 1997, with Alaska Airlines being the launch customer. The first -900’s made their test flights in late 2000, with delivery finally being made to Alaska Airlines in May 2001. However, very quickly, it became apparent that the 737-900 wasn’t exactly ringing everyone’s bells. While the Airbus A321 was selling strong with airlines both inside and outside the United States, the 737-900 had only a handful of committed orders; eventually reaching only 52. The problem was, as outlined earlier, the mixture of restricted range and capacity. The Airbus A321 can fly a distance of 3,200nmi with an average payload, while the 737-900 could only do 2,950nmi; which made it difficult to sell for longer range markets. The only Boeing product that could adequately take on the A321 was the 20 year old Boeing 757; which, by this point, had been slated for discontinuation.
Boeing had to do something to improve the breed, and thus came up with the 737-900ER (originally designated the -900X). The design called for an increased range of up to 3,200nmi, putting it directly in competition with the A321, while also matching capacity; essentially making it the replacement of the Boeing 757.
Other modifications included a reorganisation of the exit layout to try and capitalise on the aircraft’s huge amount of space. An extra pair of exit doors and a flat rear pressure bulkhead increased seating capacity to 180 passengers in a 2-class configuration or 220 passengers in a single-class layout; though some airlines seal the additional exit.
Production started on the 737-900ER in 2006, with the first flight being carried out on September 1st the same year. The aircraft gained its FAA Certification on April 26th, 2007, followed by the delivery of the first aircraft to launch customer Lion Air the very next day. The delivery aircraft was outshopped in a hybrid livery of Lion Air’s own colours on the vertical stabiliser and the Boeing Dreamliner House Colours on the fuselage. Lion Air has since remained faithful to the -900ER, with 63 aircraft on their books; though older examples are being withdrawn following the arrival of the Boeing 737 MAX series.
Plans were also made for a Boeing 737-900F, a cargo version that was marketed primarily towards Fedex to replace their ageing Boeing 727’s. The aircraft was quoted to carry up to 11 standard cargo pallets, only three less than the Boeing 757, and would be loaded by way of a side cargo door. However, Fedex instead found it cheaper and easier to buy and convert redundant passenger 757’s for the task, and thus, without any other demand, the project was scrapped.
At the time of writing (11/2018), the 737-900 has suffered no accidents or incidents, and has managed to worm its way into the hearts of many larger airlines. While the original 737-900 has faded largely into obscurity, the -900ER can now be found in the fleets of Delta Airlines, KLM and American Airlines, as well as with original launch customers Alaska Airlines and Lion Air. Today, hundreds of these aircraft are known to have been built, including 52 -900’s, 918 -900ER’s, and 7 of the tailor made but extremely expensive 737-900 Boeing Business Jets; with 152 orders yet to be filled.
So, was the 737-900 a success or a mistake?
Well, in truth, it started as a mistake, seemingly inviting with its longer fuselage for extra space, but ultimately useless in terms of when it came to fitting capacity or having it fly over long distances. It’s attempts to take on the A321 were initially all for nought, but Boeing managed to reverse their fortunes by giving it the range and the capacity it truly deserved, thereby making it both a comparable aircraft against the Airbus, but also helping to do some internal housecleaning of the product list. Overall, the 737-900 may have got off to a patchy start, but it has since been moulded and reborn to become a true airliner.