The Sriwijaya Air jet had been in storage for most of the duration of the pandemic.
The 737 that recently crashed in Indonesia was not one of the 737 MAX aircraft that is only now returning to the skies after a nearly two-year global grounding. It was a 737-500—a much older variant of the 737 family.
Sriwijaya Air Flight 182 crashed into the Java Sea four minutes after takeoff, plunging suddenly and uncontrollably into the water: 10,000 vertical feet in about 15 seconds, hitting the surface at almost 500 miles per hour. All 62 people on board were killed.
The sudden descent was reminiscent of the two deadly crashes of 737 MAX aircraft—Lion Air in October 2018 and Ethiopian Airlines in March 2019. Investigations found that a malfunction of the Maneuvering Characteristics Augmentation System (MCAS) on both aircraft led to the accidents. The planes were grounded worldwide following the second crash in March 2019 and a thorough review of the aircraft’s airworthiness—as well as Boeing’s business practices and the Federal Aviation Administration’s (FAA’s) certification processes—was conducted.
The loss of Flight 182 would have been particularly troubling in Indonesia considering that the Lion Air 737 MAX tragedy also happened in that country. However, the 737-500 variant that Sriwijaya Air was using for the flight doesn’t come equipped with the controversial MCAS, which Boeing had to significantly overhaul for the MAX to return to service.
The 737 made its debut 1967, and several variants have been introduced since then. The 737-500, part of the plane’s “Classic” series, entered service in 1989 and the MAX started commercial flights in 2017. Much of the 737’s design has stayed consistent throughout the decades, with each variant introducing technological advancements and efficiencies. But overall, the MAX is a significantly different plane than the 500.
The MAX is a larger plane, with a wider wingspan, more powerful engines and significantly increased passenger and cargo capacity:
|
Measurement |
737-500 |
737 MAX |
|
Length |
101 ft 8 in |
129 ft 8 in |
|
Wingspan |
94 ft 9 in |
117 ft 10 in |
|
Thrust per engine |
20,000 lb |
28,035 lb |
|
Total thrust |
40,000 lb |
56,070 lb |
|
MTOW |
132,000 lb |
181,000 lb |
|
Range |
2,400 nautical miles |
3,548 nautical miles |
|
Cruising speed |
Mach 0.73 |
Mach 0.79 |
|
Max. passenger capacity |
145 passengers |
210 passengers |
|
|
|
|
As you’d expect from a much newer plane, the MAX features aerodynamic modifications such as large “double” winglets, a tapered and elongated tail, and more powerful and efficient engines (in this case the CFM International LEAP engines).
While the 737-500 may be much older, it’s proven itself to be a reliable workhorse, although the plane is no longer in production and is slowly being phased out in favor of newer and more efficient models. Sriwijaya Air has also proven itself dependable with no previous casualties.
So what exactly did happen?
The speed of the descent likely means that the plane was intact, with its engines running, until impact. And the crew didn’t send out a distress call.
History of the 737.
Perhaps significantly, the plane had been parked in a hangar for the better part of a year due to the vastly reduced demand for air travel during the pandemic. Which raises the question of what potential safety hazards are there in having these aircraft sit idle for so long: parts may seize up or deteriorate, software may develop glitches, and maintenance and inspection work may not be conducted frequently enough. In addition, pilots who have been out of the cockpit for the duration of the pandemic would need to shake the rust off—likely through simulator training—before they should be cleared to fly again.
“There’s a major problem starting to raise its head in terms of restoring these aircraft because while out of service for nine or 10 months, they need to be kept operating, otherwise they deteriorate,” said Hugh Ritchie, CEO of Aviation Analysts International, an air safety consulting firm.
The black boxes of the Sriwijaya Air 737-500 have been found, and their data should help clarify why the aircraft suffered such a catastrophic failure—but the investigation could take months.
The latest variant of the 737 is the MAX 10. Read more about it at Boeing Quietly Unveils Its New 737 MAX 10.
