The first Boeing 737 took to the skies in April 1967. The twin-engine airliner with its two rows of three-abreast seating was an immediate commercial hit. Passengers loved it and so did the airlines.
By Paul Ash.
Images: Boeing Media
Lion Air Flight 610 from Jakarta to Pangkal Pinang should have been as routine as they come, an hour-long hop over the Java Sea on a route the carrier flew every day.
Yet just 13 minutes after getting airborne from Jakarta’s Soekarno-Hatta International Airport at 6.20am on 29 October 2018, the Boeing 737 MAX 8, delivered new to the airline just two months earlier, plunged out of control into the Java Sea. All 189 people aboard – 181 passengers and eight crew – were killed.
Workers on a nearby oil rig saw the aircraft hit the sea in a steep, nose-down attitude. The speed of the impact was so great that the aircraft was obliterated. The aircraft’s flight data recorder (FDR) was recovered by divers at a depth of 32m on 1 November but it took recovery teams almost another two months to locate the cockpit voice recorder (CVR) which was found buried in the mud 30m below the surface on 14 January 2019.
The recording has never been officially released although parts of it have been leaked. From parts of the transcript that were leaked, it is clear the pilots were struggling to control the aircraft almost from the moment they were airborne.
According to a Reuters report at the time, the Boeing’s angle-of-attack sensors kept indicating that the plane was in a stall even as the crew struggled to maintain the climb. The flight control system kept pushing the nose down.
Near the end of the flight, the captain handed over the controls to the first officer while he frantically scoured the quick reference handbook for a solution. It would have been no help to them to know that the very same aircraft had arrived in Jakarta the previous night with terrified passengers and crew aboard after a traumatic flight in which faulty airspeed and other sensors had made the plane almost uncontrollable.
A second crash
Five months later, on 10 March 2019, a Boeing 737 MAX 8 operated by Ethiopian Airlines took off from Addis Ababa on a route flight to Nairobi. Just six minutes after take-off, Flight 302 plunged into the ground near the town of Bishoftu, killing all 159 people on board. Just one minute into the flight, first officer Ahmednur Mohammed reported a “flight control problem” to ATC.
For the rest of the flight, Captain Yared Getachew struggled to keep the aircraft under control as the flight control system kept lowering the plane’s nose. The crew disabled the flight control system and turned the Boeing back to Bole International Airport. However, they were unable to manually correct the nose-down trim, partly because the engines were still at climb power. The aircraft hit the ground at 610 knots (1,100km/h). There were no survivors.
It was at this point that the Federal Aviation Administration (FAA) issued a global order grounding all 737 MAX aircraft until the cause of the two fatal crashes was identified. The directive affected dozens of airlines that operated the new 737, including local carrier Comair.
Grounding the aircraft cost Comair an estimated R200m, adding to the company’s financial woes, which accelerated during the pandemic and eventually led to the airline’s demise.
With dozens of aircraft now unable to fly, airlines began calling their MAX 8 and 9 orders. This, and the effects of the pandemic, cost Boeing about USD20bn and 30,000 jobs.
It was also around this time that the words Maneuvering Characteristics Augmentation System (MCAS) became something of a buzzword to journalists and also to an increasingly nervous flying public.
A feature or a bug?
How, then, did the world’s most successful short-haul commercial airliner tumble from grace like this?
The first Boeing 737 took to the skies in April 1967. The twin-engine airliner with its two rows of three-abreast seating was an immediate commercial hit. Passengers loved it and so did the airlines. More than 11,000 have been built to date in a slew of variants, starting with the 737 “Original”, all the way up to the current 737 MAX. It would be fair to say that the airliner helped boost confidence among the flying public while also helping airlines operate profitably.
The airline business, however, flies on notoriously thin margins. Where fuel once accounted for roughly a third of a carrier’s operating cost, it is now around 50%. That steady increase, in turn, has pushed aircraft designers to seek the most efficient mix of power and airframe they can find.
No-one today would design a 100-seat airliner powered by thirsty JT8D turbojets and expect the airlines to queue up to buy it.
Instead, the Boeing 737 has stretched to carry more passengers and that, in turn, has meant using different engines. It is with the engines that the first inklings a problem arose with the 737 MAX.
The Max is powered by LEAP-1B engines which are significantly larger than the engines that powered the original 737. Accommodating these new engines meant placing them forward of the wing and slightly higher. This in turn altered the aircraft’s handling characteristics, most notably causing the nose to pitch up at a high angle of attack (AOA) at high airspeed.
Boeing’s solution to the problem was the MCAS, which is essentially software that used data from a single sensor to adjust the aircraft’s control surfaces in flight.
On paper – and, in fact, in service with many airlines – the MCAS worked well, and many experienced 737 pilots praised the MAX for its handling qualities. Just two faulty sensors, however – one of each of the accident aeroplanes – were enough to tarnish the Boeing story, probably forever.
The blame game
Six years after Lion Air 610 fell into the Java Sea, the 737 MAX is making the news once more – and not in a good way. In January, a door plug departed an Alaskan Airlines 737 MAX at 32,000ft because critical bolts holding the plug in place had not been refitted by technicians, causing an explosive decompression of the cabin.
In February, Boeing announced it would have to inspect as many as 50 new 737 MAX fuselages currently being built after incorrectly drilled holes were discovered on a pressure bulkhead. Many have ascribed these problems to an alleged poor safety culture at Boeing as the company pursues profits.
Yet in the wake of the two fatal crashes many observers were quick to blame the respective crews, noting that the first officers on both flights were relatively inexperienced. There is also speculation over how much the crews knew about the MCAS and how it worked.
The sequence of events that ultimately led to both crashes is more prosaic, starting with a change of leadership at the US plane manufacturer. In 1997, Boeing bought out McDonnell Douglas Corporation in a deal that saw the president of the smaller company, Harry Stonecipher, take the hot seat at Boeing. Stonecipher would later say in an interview with the Chicago Tribune that his intention at Boeing was to ensure it was “run like a business rather than a great engineering firm”.
Fifteen years later, long after Boeing’s dominance in the US commercial passenger jet market had been shredded by Airbus, the US jet maker learned that American Airlines – the uber customer for airliners – was considering a mass order of the A320 Neo. There was no time for Boeing to design and build a new aircraft from scratch. To compete with the Europeans meant a redesign of its bread-and-butter product – the venerable 737.
Cynics will tell you that 20/20 hindsight is an exact science. In Boeing’s rush to bring a new aircraft to the world in the form of the 737 MAX, with its many compromises and flaws, they may have a point.
737-7 | 737-8 | 737-9 | 737-10 | |
Seats (2-class) | 138-153 | 162-178 | 178-193 | 188-204 |
Maximum seats | 172 | 210 | 220 | 230 |
Range nm (km) | 3,800 (7,040) | 3,500 (6,480) | 3,300 (6,110) | 3,100 (5,740) |
Length | 35.56m (116ft 8in) | 39.52m (129ft 8in) | 42.16m (138ft 4in) | 43.8m (143ft 8in) |
Wingspan | 35.9m (117ft 10in) | 35.9m (117ft 10in) | 35.9m (117ft 10in) | 35.9m (117ft 10in) |
Engine | LEAP-1B from CFM International | LEAP-1B from CFM International | LEAP-1B from CFM International | LEAP-1B from CFM International |