Like clockwork, every 18 months to two years, a passenger airliner goes down in Indonesia. Investigators determine the cause, level blame at various people and entities, and issue recommendations meant to ensure that it never happens again. And yet, inevitably, it does.
On January 9 this year, people around the world awoke to the news that yet another Indonesian Airliner had crashed with no survivors. Preliminary data showed the crew of Sriwijaya Air flight 182 lost control of their plane while dealing with what should have been a minor malfunction – the same basic cause behind many of Indonesia’s worst air disasters in recent years. Why is it that Indonesia, more so than almost any other country, is unable to apply the lessons of the past to prevent future tragedies? And will anything ever change?
Perhaps the most illustrative answers to these questions lie in the story of Adam Air flight 574, another Boeing 737 with a troubled Indonesian budget airline, that disappeared on New Year’s Day 2007 during a storm over the Makassar Strait. Experts would find that as the pilots tried desperately to fix a malfunctioning navigation system, they let their plane turn over into a terrifying dive that ripped the 737 apart in midair.
But from the founding of the airline to the maintenance of the crashed plane to the search for the wreckage, the real causes revealed themselves to be rampant corruption, disregard for regulations and outright criminal activity. These were all products of a culture of unfettered profiteering and lax government oversight that has caused an epidemic of air crashes in Indonesia, and will continue to do so if it is not brought under control.
The early 2000s saw exponential growth in Indonesia’s airline industry. In seven years, passenger numbers quintupled, driving a frenetic expansion in the size and number of low-cost carriers. Among these was Adam Air, a budget airline founded in 2002 by wealthy businesswoman Sandra Ang and Agung Loksano, the speaker of Indonesia’s House of Representatives.
The airline was named for Ang’s son Adam Suherman, who at the age of just 26 was appointed CEO. Adam Air was a family-run operation: In addition to Suherman, two of his brothers and Loksano’s son also held top management positions.
Catering to the explosion in demand, Adam Air grew rapidly, expanding its market share at a rate that bordered on alarming. By the end of 2006, it had built up a fleet of 25 Boeing 737s and was the fastest-growing airline in Indonesia. In the process, Adam Air was often accused of false advertising, such as describing its 15-year-old 737–400 planes as “new” and other questionable assertions. Its logo, which appeared to feature a silhouette of Icarus, the man who flew too close to the sun, also did not inspire confidence.
Among Adam Air’s fleet was an 18-year-old Boeing 737–400 registered as PK-KKW. One of several trips in this airplane’s schedule on New Year’s Day 2007 was flight 574, a routine journey between the cities of Surabaya in eastern Java and Manado on the island of Sulawesi. In command was Captain Refri Widodo, an experienced pilot with over 13,000 flight hours. His copilot was First Officer Yoga Susanto, who had a fairly respectable 4,200 hours of his own. Joining them were four flight attendants and 96 passengers, totaling 102 people on board.
Widodo and Susanto were probably aware that PK-KKW had a history of problems with its inertial reference system (IRS), a network of sensors and computers that measure the position of the airplane in three-dimensional space. The IRS contains two subsystems, one for each pilot, each of which features an inertial reference unit (IRU) consisting of three gyroscopes that provide data to the pilots’ instruments and computerised displays. For months, pilots had been reporting that the two IRUs disagreed about the lateral position of the airplane. However, maintenance had been unable to fix the problem.
Adam Air flight 574 took off at 13:59 local time, heading northeast over the Makassar Strait to Manado. But within minutes, the position of the plane indicated on the pilots’ displays began to differ. One of the IRUs was producing invalid data, and the pilots needed to figure out which one.
By the time the cockpit voice recording began at 14:28, Captain Widodo and First Officer Susanto were already discussing the problem.
“Twenty-eight is the difference,” Widodo reported, confirming a 28-nautical-mile discrepancy in the location of the plane on the two displays. In fact the autopilot had been following the wrong one for some time, because the plane was off course, drifting north of its assigned route. Controllers in Makassar began to grow concerned. Amid conversations recorded in the control tower, one of them exclaimed: “Where’s Adam direct to? My god, he’s flying north!”
In the cockpit, the pilots joked about the situation, even as they strayed further from the proper track and approached a powerful thunderstorm. Turbulence battered the plane as they entered the storm, and the pilots turned on the fasten seatbelt signs.
As the pilots struggled with the malfunctioning system, their conversations became increasingly agitated:
“Verify position, we can get lost if it is like this!”
“Crazy, it’s crazy!”
“We can’t just turn off one of the IRS!”
“Now the left one is good, the right one is different, you’re kidding!”
“Whoa, something is disengaged!”
“This is messed up!”
“It’s starting to fly like a bamboo ship!”
“The FMS is confusing itself, that’s crazy!”
At 14:47, they finally decided to check for an official procedure to troubleshoot the IRS.
“Have a look at the QRH,” Captain Widodo suggested, referring to the Quick Reference Handbook of abnormal procedures. “If the IRS number two is switched off, see what happens.”
“IRS,” said Susanto, flipping through the booklet. After a few moments he found it. “IRS Fault,” he said, presumably looking at the IRS Fault procedure in the QRH.
But the IRS fault light had not illuminated. Was this the right procedure? The pilots proceeded to argue about it for the next several minutes.
At 14:55 the controller informed the crew of their position and told them which way to fly. Blindly following the instructions, they began to turn to the east. The pilots could have used this information to determine which IRS was correct, but it seems that they did not.
Instead, the pilots decided to try a troubleshooting method suggested in the QRH. The procedure called for them to turn off the navigation functions of the IRS while keeping the other functions, which were working correctly. To accomplish this they would need to move the mode selector switch of the faulty system from “NAV” (navigation mode) to “ATT” (attitude mode). The procedure advised that after flipping the switch, the pilots would need to hold the plane straight and level for 30 seconds while the system reboots.
This process would require the pilots to pay careful attention. As the IRS reboots, it goes through an alignment process in order to determine the orientation of the plane in space. The autopilot will disconnect and the instruments on the affected side will go blank, displaying no pitch or roll information. After 30 seconds of stable, level flight, the gyros will align and these systems will come back. Thereafter, the pilots would need to navigate manually.
At 14:56, Widodo ordered Susanto to move the IRS mode selector to attitude mode. Susanto still didn’t understand which IRS was faulty: was it the left one? Widodo told him it was the right one. Susanto then switched his own (right-hand) inertial reference system to attitude mode. All his screens went blank and the autopilot disconnected, triggering a loud alarm. Someone reached over and shut it off.
The chilling clackclackclack of the overspeed warning filled the cockpit as they approached the speed of sound
But the faulty navigation system wasn’t the only thing wrong with this plane. PK-KKW also tended to pull to the right due to a slight mistrimming of the ailerons, which control roll, requiring constant correction in order to maintain straight and level flight. Until now the autopilot had been doing this, but when the autopilot disconnected, Captain Widodo needed to take manual control to level the plane. But he must have thought the autopilot was still flying the airplane, because he took no action. Imperceptibly at first but gaining speed, the plane started to roll to the right all by itself.
Plowing onward through the storm, surrounded by howling wind and driving rain, the pilots continued to fight with the IRS. Captain Widodo intervened twice to level the plane but failed to hold it steady. Susanto’s IRS failed to align because they were turning, and his instruments didn’t return after 30 seconds. They were starting to lose the plot.
At 14:58 the bank angle increased through 35 degrees, causing an automated voice to call out, “BANK ANGLE! BANK ANGLE!”
“Put it back on NAV again!” Captain Widodo exclaimed. The effects of switching the IRS mode had spooked him, but instead of following the airman’s proverb – “just fly the airplane” – he tried to undo the input that had gotten them into the situation.
The plane was now banking so far that the wings began to lose lift, causing the nose to drop. A chime sounded to inform the pilots that they were leaving their assigned altitude of 35,000 feet.
“Don’t turn it! This is our heading!” Captain Widodo shouted. They were banking past fifty degrees. What was he thinking?
Flight 574 kept rolling until it was upside down, reaching a bank angle of 100 degrees. Losing lift, the plane pitched steeply downward and entered a rapid descent. Suddenly realising that they were in danger, Widodo grabbed the controls and pulled back sharply. But because the plane was inverted, pulling up caused them to dive straight at the ground instead.
Massive G-forces smashed the passengers and crew into their seats as the plane hurtled into a terrifying spiral dive, accelerating downward at incredible speed. The chilling clackclackclack of the overspeed warning filled the cockpit as they approached the speed of sound.
“Pull up! Pull up!” screamed First Officer Susanto.
But there was nothing they could do. The plane was experiencing extreme G-forces at an airspeed of 900km/h, far beyond its design limits. Two loud thunks reverberated through the plane as the incredible aerodynamic forces ripped off part of the tail. The rate of descent reached 53,000 feet per minute. The plane began to disintegrate; in the cockpit, the only sound was the deafening roar of the wind. Finally, at a height of 9,000 feet, both black boxes stopped. What happened after that is a secret that the 102 passengers and crew took with them to their watery graves.
At the control centre in Makassar, ten minutes passed before controllers realised that flight 574 had disappeared from radar. For two hours, they called other pilots and airports to ask if anyone had seen the 737, but it seemed to have vanished without a trace. Finally, at 17:24, the control centre activated the “aircraft in distress” protocol and a search and rescue mission launched into action.
The search for the plane had little to go on. Based on its last recorded radar position, it wasn’t even clear whether the plane had crashed on land or at sea. Military personnel scoured the jungle-covered mountains of southwestern Sulawesi on foot, while boats crisscrossed the Makassar Straight in search of floating debris. Days passed, but nothing was found.
Then on January 11, fishermen off the coast of Sulawesi began to find floating debris, including battered flight controls, a few mangled cabin furnishings, and several personal effects. Some of these had likely been ejected from the plane in flight.
Two weeks later, a US vessel carrying specialised equipment detected the “pingers” from the two black boxes, which appeared to be lying on the ocean floor around 1.4 kilometres apart amid the widely scattered remains of the airplane. There was just one problem: The recorders lay more than 2,000 metres below the surface, and no country in Southeast Asia had a submersible that could recover them from this depth.
The Indonesian government expected Adam Air to pay to hire a foreign salvage company to retrieve them. But Adam Air refused to pay a single penny: company executives didn’t seem to think that finding the cause of the crash was important, and that if the government wanted to know, they ought to pay for it themselves. The cost could run to tens of millions of dollars, and the cash-strapped government was not keen on paying it either. With neither side willing to budge, negotiations stalled. For seven months, family members and aviation experts waited and waited, increasingly concerned that the crash of Adam Air flight 574 might forever remain a mystery.
Finally, in July 2007, Adam Air agreed to pay half the cost of one week of searching. Faced with this stingy offer or no offer at all, the Indonesian government agreed. By mid-August, a Phoenix International salvage ship equipped for deep-water recovery missions was on its way from the US.
Armed with the known positions of the black boxes, Phoenix International located both recorders within five days; both were found a few metres from where the coordinates said they would be. The data they contained would be all investigators would get: there wasn’t enough time or money to retrieve anything else. Nor did the search find any bodies; in fact, the crash was so violent that the 102 passengers and crew would have been all but vaporised on impact.
The flight data recorder and cockpit voice recorder revealed a bewildering series of events. First, one of the inertial reference units malfunctioned, sending incorrect commands to the autopilot that slowly steered them off course. After about 20 minutes the discrepancy probably became large enough to trigger a warning, after which it occupied the majority of the pilots’ attention for the rest of the flight.
Although investigators could not determine the cause of the glitch without examining the IRUs, the source of the problem didn’t really matter. An issue with the inertial reference system should not cause a dramatic plunge into the sea; rather, the answer had to do with the way the pilots reacted.
According to proper principles of airmanship, the captain should have designated one pilot to take charge of troubleshooting while the other flew the airplane. But in the event, both pilots became occupied with troubleshooting the IRS for nearly 30 minutes without paying attention to what their airplane was doing. Throughout this period they continued to diverge from the designated airway and flew into a severe thunderstorm, but they failed to make use of information that could have helped them get back on course.
When they finally decided to reset the malfunctioning IRS, they badly botched the procedure. Although the checklist clearly stated that they would need to keep the plane straight and level for 30 seconds while Susanto’s IRS rebooted, they did not appear to understand this, nor did they realise that moving the switch would disconnect the autopilot. Despite the fact that someone actively disabled the autopilot disconnect alarm, neither pilot acknowledged that it was no longer engaged. Their action was automatic – they silenced the alarm without ever processing its importance, because their minds were fixated on the navigation system.
From there, events escalated rapidly. Assuming that the autopilot was still holding them level, the captain failed to steady the airplane, and the mistrimmed ailerons caused a right roll to develop at a rate of one degree per second. Consequently the IRS alignment process failed, leaving the first officer without his instruments for the rest of the flight. Still, both pilots kept trying to solve the problem even as the plane turned ever more steeply. Few attempts were made to stop the roll until it reached 100 degrees, despite numerous warnings. At this point Captain Widodo sealed their fate by pulling up before rolling wings-level, when he should have done it the other way around. Pulling up while upside down put them into such an extreme dive that within seconds the aircraft became unrecoverable.
To better understand the accident, Indonesia’s National Transportation Safety Committee, or KNKT, examined Adam Air’s pilot training and maintenance programmes. Immediately they noticed that Adam Air had given its pilots copies of the operations manual downloaded from myboeingfleet.com, which were explicitly marked as ‘not for operational use.’
Furthermore, Adam Air had not trained its pilots to respond to failures of the IRS, or any other automated system. They weren’t trained how to react to an unexpected autopilot disconnect warning. And they hadn’t received upset recovery training, a standard module at Western airlines, which among other techniques teaches pilots to roll wings-level before pulling up while in an inverted position.
In all respects, the pilots were unprepared for the situation they encountered. Without the requisite training, they bungled their way through the IRS troubleshooting process, making a series of ill-informed decisions, then lost control of a perfectly controllable airplane because they weren’t paying attention. It was a shocking indictment of the pilot training at Adam Air, but that was just the tip of the iceberg.
The KNKT soon discovered that Adam Air’s maintenance programme also left much to be desired. Records showed that one of the inertial reference units on PK-KKW had been written up more than 100 times in the last three months, usually because it was drifting abnormally, just like on flight 574. But Adam Air didn’t have a replacement available – ordering a new one would take six months – so every time a fault arose, mechanics simply removed the unit, cleaned the connections, re-racked it, or swapped it with the other IRU.
It was obvious that none of these measures were fixing the problem. According to proper procedure, they should have inspected the wiring, and failing that, the system should have been replaced. But poorly trained mechanics and a lack of spare parts – caused by management underestimating how many they would need – led to a culture where aircraft faults were usually “fixed” through the maintenance equivalent of turning it off and back on again. Although Adam Air supposedly had a quality control programme approved by the government, the KNKT concluded that it only existed on paper.
Every time you flew, you had to fight with the ground staff and the management about all the regulations you had to violate
Following the crash, former Adam Air pilots claimed that management forced them to fly unairworthy airplanes and sign off on maintenance logs that hadn’t been examined by engineers. Others revealed that Adam Air evaded repair deadlines by swapping faulty parts to another aircraft to reset the repair period, then bribed regulators to look the other way. Yet another pilot said that after he refused an order to exceed his legal duty limit, the airline retaliated by grounding him for a week.
“Every time you flew, you had to fight with the ground staff and the management about all the regulations you had to violate,” he told the Associated Press.
The crash of Adam Air flight 574 was not the first eyebrow-raising incident at the airline, nor was it the last. In February 2006, an Adam Air Boeing 737 with a faulty IRS flew off course into a radar dead zone over the ocean, causing the crew to get lost circling for more than three hours. Eventually they spotted the rural island of Sumba, where they landed safely despite having no idea where they were.
Adam Air claimed that nothing was wrong with the plane and had the pilots arrested by local authorities on charges of “endangering public safety”. Indonesia’s Directorate General of Civil Aviation (DGCA) was not convinced, and the agency ordered Adam Air to repair the navigation system and conduct a series of tests to ensure it was working correctly. But, according to the Asia Times, an Adam Air plane which was supposed to take KNKT investigators to the site of the incident “accidentally” left without them, and then the airline explained that their mechanics had apparently fixed the issue and there was no need for further investigation.
Then, in February 2007, an Adam Air flight was landing in Surabaya when it touched down so hard that the fuselage broke, causing the tail section to collapse. Five Adam Air 737s were grounded for structural inspections, despite Adam Air’s complaints that this “punishment” was too “harsh”.
Finally, in March 2008, another Adam Air flight skidded off the runway while landing in Batam, damaging the right wing. After the crash the crew mishandled the evacuation by failing to deploy any emergency slides. By this point it was clear that if left unchecked Adam Air would inevitably have another fatal accident.
Days after the crash in Batam, a group of investors dumped their 50% stake in the airline, causing Adam Air to miss lease payments, which forced their lessors to repossess half the fleet. Two days later, the DGCA suspended their Air Operator Certificate, and revoked it completely in June. At last, Indonesia’s sketchiest airline was dead.
Indonesians felt it was scandalous that Adam Air had continued flying for more than a year after the crash of flight 574, despite its complete disregard for safety. Many believed that Adam Air got away with its blatant regulatory violations because its co-founder was also the Speaker of Indonesia’s House of Representatives. Indonesian newspapers alleged that Loksano didn’t make an initial investment when the airline was founded, because his role was actually to ‘smooth out’ Adam Air’s relationship with regulators by using his position to twist arms and dispense bribes.
Then in August 2008 came another bombshell: Adam Air founder Sandra Ang was arrested by Indonesian police and charged with embezzling over $200 million from her own airline. Whether she was convicted remains unclear, but if true, the massive embezzlement would suggest that Adam Air was always a criminal enterprise designed to enrich its owners.
Following the crash and the grounding of Adam Air, Indonesian regulators drafted a series of tough new rules for every airline in the country. But DGCA officials acknowledged that writing rules wasn’t the hard part: the hard part was finding inspectors who couldn’t be bribed. According to then-Transport Minister Hatta Radjasa, corrupt officials presented a major barrier to implementing new safety measures. He followed up his complaints with an announcement of new inspections, but it was later reported that these measures never took effect.
These problems were symptomatic of a civil service culture which lacked respect for the rule of law. In fact, officials were accused of being more sensitive about the perception of Indonesia’s aviation industry than about the fact that it was unsafe. Critics pointed to a high-profile televised ramp inspection that grounded five aircraft but was widely dismissed as a publicity stunt. For the DGCA, which lacks the funds to enforce its own rules and train experienced inspectors, genuine enforcement measures are prohibitively expensive.
Furthermore, inspectors who don’t understand their responsibilities and receive low salaries are more likely to take bribes. In fact, for this reason AeroTime Aviation News has described the DGCA itself as the biggest threat to air safety in Indonesia. After another crash in March 2007, the European Union added all Indonesian Airlines to its safety ‘blacklist;’ some of them are still on it today. Likewise, the US Federal Aviation Administration for a number of years included Indonesia in its list of countries that lacked the capability to enforce international safety standards.
By 2016, Indonesia still ranked among the worst in Southeast Asia in its implementation of safety legislation, organisation, licensing, and operations (only Thailand scored lower). Analysts believe that investment in the civil aviation sector by the government of Indonesia is the only way to turn things around, but the funds have not been forthcoming.
Indeed, the data show that aviation safety in Indonesia is improving unacceptably slowly, and it will be decades before it reaches the world average. As if to demonstrate how little progress had been made, in December 2014 an Indonesia AirAsia passenger jet crashed, killing all 162 people on board, after the pilots lost control of their plane. Once again, the pilots of AirAsia flight 8501 accidentally disconnected the autopilot while troubleshooting a minor malfunction that hadn’t been fixed, then panicked and put the plane into a dive.
In its final report on the crash of Adam Air flight 574, and again after AirAsia flight 8501, the KNKT made numerous safety recommendations, many of which eventually found their way into the rulebooks. And again, officials vowed that things would change. But they didn’t. In fact, Indonesia’s aviation industry does not appear to work any differently today than it did in 2007, or in 2014.
Indeed, when Sriwijaya Air flight 182 crashed near Jakarta in January 2021, the black boxes revealed yet another an eerily similar sequence of events. On that flight, a malfunctioning automated system caused one engine to stick at high power, resulting in a roll to the left. It should have been trivial to recover, but the pilots didn’t react until it was too late, by which time the plane had rolled upside down; it then dived 10,000 feet in 20 seconds before slamming into the ocean, killing all 62 people on board.
Fourteen years after the Adam Air disaster, seven years after AirAsia, it has happened again. And again people will ask: how was Sriwijaya Air maintaining its planes? Why wasn’t the throttle problem fixed? Why weren’t the pilots trained to recover? And where was the DGCA?
In light of this disaster, we must also ask: was anything learned from the crash of Adam Air flight 574? If an almost identical accident can happen in 2021, we must conclude that the answer is no.
Kylan Dempsey is an American graduate student who writes articles breaking down plane crashes for both professional and lay audiences. You can find a body of his work on his Reddit and Medium pages.