The plane that Sriwijaya Air was flying is a 737-500 model that’s much older than the 737 Max aircraft.
Weather has been a contributing factor in several of the past crashes. On Saturday, heavy rain in Jakarta delayed the takeoff for the 90-minute SJ182 flight to Pontianak on the island of Borneo.
It finally took off at 2:36 p.m. local time, reaching 1,700 feet a minute later, where it was cleared by Jakarta air traffic controllers to ascend to 29,000 feet, according to Transportation Minister Budi Karya Sumadi. Four minutes after takeoff, controllers noticed the aircraft was not on its assigned track. It radioed the crew, and within seconds, the aircraft disappeared from radar, he said.
Flightradar24’s tracking data showed the plane leveling off at an altitude of about 10,000 to 11,000 feet 3 minutes after taking off, before a rapid descent to the water in just 14 seconds. That meant it was dropping at more than 40,000 feet per minute, a rate far above routine operations.
Preliminary readings from flight data transmitted by the aircraft via the Automatic Dependent Surveillance–Broadcast system appeared to show “possible disorientation” by the pilots, said aviation analyst Gerry Soejatman.
“While we have to wait for the final report of the investigation to know the true cause of the incident, but the preliminary data appears pointing to possible disorientation in the cockpit, to which the bad weather is a factor here,” he said.
Without access yet to the plane’s black-box flight recorders, it’s impossible to say what may have triggered the sudden dive, said Jeffrey Guzzetti, the former head of accident investigations at the U.S. Federal Aviation Administration. “Right now, given the amount of sparse information, that flight track could fit many scenarios, such as flight crew confusion, instrumentation problems, catastrophic mechanical failures or even an intentional act,” he said.
deployed divers, warships, vessels with sonar and airplanes on Sunday. Of the 62 people, 50 were passengers, including seven children and three infants, and there were two pilots, four cabin crew and six off-duty crew, local media reported. There were no foreign nationals on board.
Boeing is “closely monitoring the situation,” spokeswoman Zoe Leong said in a statement. “We are working to gather more information.” Sriwijaya Air said it will work with relevant authorities in evacuation and investigation efforts.
The 737-500 model first flew in 1989 and, according to tracking website Planespotters.net, this particular plane first flew in May 1994.
“This is not even the model before the Max, it has been in service for 30 years so it’s unlikely to be a design fault,” said Richard Aboulafia, an aviation analyst at Teal Group Corp. “Thousands of these planes have been built and production ended over 20 years ago, so something would have been discovered by now.”
The crash comes as the aviation industry is reeling from the effects of the coronavirus pandemic, which brought air travel to its knees. Covid-19 tore through in a tumultuous, unprecedented way -- leaving carriers in a deep hole, along with a constellation of aerospace manufacturers, airports and leasing firms. The International
Air Transport Association said last week that global passenger demand dropped significantly during November, down 70% versus the same period of 2019 when measured in revenue passenger kilometers.
“While we don’t know anything else about the cause of this crash, the biggest thing concerning me is serious concerns about Indonesian air safety standards that were identified by the European Union Aviation Safety Agency and others
years ago,” Aboulafia said. “I am not completely certain that the proper procedures have been put in place.”
The U.S. National Transportation Safety Board has appointed a senior investigator to assist in the probe, but is awaiting more information before determining whether it will send a team, it said in an emailed statement. Under a United Nations treaty, the NTSB along with technical experts from Boeing and possibly the manufacturers of other components would participate in the probe because the jet was built in the U.S.
Indonesia’s transportation safety committee has started its probe, including by retrieving air traffic communication and radar information as well as by interviewing officials who were on duty, according to lead investigator Nurcahyo Utomo. The committee is working with the government to let foreign investigators enter the country despite the current travel ban, he said.
Indonesia, which had one of the fastest-growing airline industries in the world prior to Covid, has a patchy safety record when it comes to air accidents. Its poor aviation history saw carriers from the nation banned from the European Union in 2007 and it was only in June 2018 that the full ban was lifted. In 1997, Garuda Indonesia
Flight 152 crashed approaching an airport in Medan in North Sumatra, killing 234. The AirAsia Flight 8501 that crashed in late 2014 was en route to Singapore from Surabaya.
On Oct. 29, 2018, the Boeing 737 Max flown by Lion Air plunged into the Java Sea 13 minutes after takeoff, killing all 189 passengers and crew. That was Indonesia’s second-deadliest aircraft accident.
The coronavirus pandemic has complicated aviation insomuch as pilots aren’t getting enough opportunities to fly because airlines
have grounded planes and scaled back operations due to a slump in demand. On Sept. 15, an Indonesian flight carrying 307 passengers and 11 crew to the northern city of Medan momentarily veered off the runway after landing, sparking an investigation by the transport safety regulator. It found the pilot had flown less than three hours in the previous 90 days. The first officer hadn’t flown at all since Feb. 1.
“This concern about lack of flying hours among pilots might have materialized here,” Soejatman said. “The Indonesian airlines
domestic market is rebounding from the Covid hiatus and this might have put significant strain on the crew. Compound that with all the personal conditions that these people might have from the reduced pay and everything, this is a challenging time for the industry.”
Saturday’s accident also follows a tumultuous period for Boeing, which only in November had its 737 Max cleared to fly again by the U.S. Federal Aviation Administration, ending the longest grounding of a jetliner in U.S. history. Brazil’s Gol Linhas Aereas Inteligentes SA was the first airline to resume regular flights
using the jet, beginning Dec. 9 on domestic routes from Sao Paulo. American Airlines
Group Inc. has since also reintroduced the Max on Miami-New York flights.
Earlier this month, Boeing reached a $2.5 billion agreement with the Justice Department to settle a criminal charge that it defrauded the U.S. government by concealing information about the 737 Max, capping a two-year investigation that devastated the company’s reputation for engineering prowess.
Sriwijaya Air was established in November 2003. Its fleet is comprised of the Boeing 737 family of jets and ATR 72-600 turboprops. While the company primarily serves domestic routes, it flies internationally to Penang, Malaysia and Dili, Timor Leste. Flag carrier PT Garuda Indonesia briefly took over the operation of Sriwijaya and its unit NAM Air in 2018 to expedite Sriwijaya’s debt restructuring, including clearance of dues to Garuda’s unit.
The Boeing jet in question had been operated by Sriwijaya Air since 2012, according to fleet data on Planespotters.net, and was previously used by Continental Air Lines and United Airlines Holdings Inc.