3 hours to pack and go: Singapore’s transport accident investigators race to piece together what happened

SINGAPORE – Three hours. This brief pocket of time is enough for a small team of aviation investigators from a Ministry of Transport (MOT) department to get ready to jet out, if an incident involving a Singapore-registered aircraft has occurred overseas.

When Singapore Airlines flight SQ321 was hit by turbulence on May 21, resulting in a death and multiple injuries, investigators from the Transport Safety Investigation Bureau (TSIB) hopped onto a flight chartered for the airline’s employees to Bangkok’s Suvarnabhumi Airport.

They were on the ground by 10.45pm Singapore time, just six hours after the turbulence-stricken SIA flight made an emergency landing in the Thai capital.

The bureau is now in the spotlight with its investigations of SQ321, and before that, of the Singapore-flagged ship involved in a collision with a Baltimore bridge in March that killed six in the resulting bridge collapse.

The investigators declined to go into details of the ongoing investigations.

The TSIB does not just probe air, marine and rail incidents that occur in Singapore, but also those overseas involving Singapore-registered or operated aircraft and ships.

It looks into rail incidents that involve fatalities or serious injuries from train operations, derailment, collision, breakaway rail vehicles and rail explosions.

When they get the call that there has been an incident overseas, TSIB aviation investigators will first meet at their office at Changi Airport Terminal 2 before deciding on the team of two to three investigators who will run the probe.

In an interview with The Straits Times on June 10, Mr David Lim, principal investigator and head of the training section at TSIB, who specialises in aviation investigations, said the three-hour countdown begins when the team has been decided on.

The 59-year-old, who has 17 years of experience as a safety investigator, has become used to being activated at any time, and has a “go-bag” of necessary equipment on standby in the office.

A go-bag – an emergency kit – usually includes personal protective equipment such as a hazmat suit, yellow evidence markers, camera, and a GPS tracking device, among other things.

On top of that, the investigators know they have to throw together personal belongings if they have to get on a plane.

“My wife knows what I need,” he said. “So when I’m deployed, I have someone at home to pack my socks, underwear, jeans, T-shirts, toiletries… (She’ll) just throw them all in, and I’ll go home to pick it up and ‘zao liao’ (leave).”

The real action begins when the team arrives at the accident site.

Wearing personal protective equipment to shield themselves against possibly contaminated body fluids, the investigators photograph different parts of the scene that they organise with numbered evidence markers.

By the time they get there, any human remains would have usually been removed, said Mr Lim.

The team uses a GPS tracking device with centimetre-level accuracy and a 3D laser scanner to accurately document the site, allowing the investigators to superimpose the location data on Google Maps and revisit the 3D model of the scene later.

A marine safety investigator is recording how the scene looks like in the engine room on board a ship with a 3D scanning device. PHOTO: TRANSPORT SAFETY INVESTIGATION BUREAU (TSIB)

Drones are sometimes used to photograph an aerial view of the site if there are skid marks or debris scattered over a runway.

TSIB aviation safety investigators practise the use of a tethered drone to collect evidence in a training exercise. PHOTO: TRANSPORT SAFETY INVESTIGATION BUREAU (TSIB)

If the aircraft is underwater, they may use an underwater locator beacon detector, which can pick up signals down to 1,000m, to locate the memory module of an aircraft’s flight recorder.

Underwater location beacon detectors are used by TSIB aviation safety investigators to find the aircraft’s “black box”, which contains the flight data recorder and cockpit voice recorder. PHOTO: TRANSPORT SAFETY INVESTIGATION BUREAU (TSIB)

There are also interviews to be conducted with flight crew, passengers and eyewitnesses.

The time taken to finish documenting the site varies for different cases, noted Mr Lim, depending on the scale of the incident and the size of the site. In the case of SQ321, TSIB said the investigators returned from Bangkok to Singapore on May 23 after collecting evidence, and investigations are under way.

The crux of the investigation lies in what is commonly known as an aircraft’s “black box” that the team retrieves from the site, containing the flight data recorder and cockpit voice recorder.

The flight data recorder provides investigators with information such as the wind speed, altitude, flight direction and aircraft position. The cockpit voice recorder allows them to listen to the pilots’ conversations, their communication with air traffic controllers, as well as noise from outside the aircraft.

External noise is one of the many clues the team looks out for, as it could indicate if an engine failure or explosion, or heavy rain, may have contributed to an incident.

Back at the TSIB office, the investigators try to piece together what went wrong. They will then construct a sequence of events for the final investigation report summarising their findings.

For Mr Lim, an investigation is about “closing doors” on possibilities as they are eliminated, and “walking through” the remaining open doors to get closer to the truth.

Sometimes, investigators may issue an interim update if there are urgent safety concerns to be addressed. For SQ321, for instance, the team put out a report about eight days after the incident, with a timeline of the occurrence.

Mr Lim is among 11 air safety investigators at TSIB – some of whom are former pilots and aircraft engineers – aged 36 to 71 years old.

In addition, there are three marine safety investigators aged 47 to 63 years old, who were previously master mariners with the Maritime and Port Authority of Singapore (MPA).

The rail safety investigation team of three, aged 35 to 37 years old, previously had rail-related engineering, safety and management experience with a rail regulator and rail operators.

Besides the 17 investigators, TSIB has three support staff and is in the process of recruiting two more marine investigators.

With 19 years of experience in aircraft engineering and maintenance, Mr Lim ventured into aviation investigation with TSIB in 2007 after deciding to widen his perspective – beyond “purely maintenance” – of the air industry.

With 19 years of experience in aircraft engineering and maintenance, principal investigator and head of training section David Lim, 59, has been involved in aviation safety investigations for the past 17 years. ST PHOTO: SHINTARO TAY

His most memorable investigation to date involved an aircraft less than a year old that crashed into the sea and had to be cut into four pieces to be lifted out of the water.

First named the Air Accident Investigation Bureau when it was set up in 2002, TSIB was restructured in 2016 to expand its investigative scope to the marine sector.

Its purview was further extended in 2020, after Parliament passed a law for it to also investigate rail and selected bus incidents. Mr Lim noted that investigators across different sectors can be “cross-deployed” to assist with probes beyond their respective specialities.

The Transport Safety Investigations Act, which aligns the laws for transport safety investigations across the different transport modes, officially kicked in on Jan 1, 2024.

Incidents at sea

The investigative process is different for incidents that happen out at sea, as it is often hard to reach the site quickly.

Mr Khalled Jalil, a marine safety investigator at TSIB for almost two years, told ST that shipboard incidents such as ship collisions or equipment failure may be reported only a day or more afterwards, after the crew has stabilised the ship.

Instead of heading to where the incident occurred, investigators often wait for the vessel to return to the nearest port. The 51-year-old former seafarer adds that most ships will call at Singapore’s port, as it is one of the world’s busiest.

As with air accidents, marine safety investigators rely on information collected from the vessel’s voyage data recorder and interviews with the ship’s crew.

When investigating incident sites, the marine team is equipped with personal gas detectors and intrinsically safe cameras or phones – devices that are safe for use in potentially explosive environments on gas carriers or tankers.

Mr Khalled added that it is useful to ask crew members for photographs or footage shot at the time of the incident, which can provide crucial additional information on the positioning or status of the equipment.

From fishing out dead bodies from the water during his time with the Singapore Police Coast Guard to conducting investigations for MPA, Mr Khalled, who has 34 years in the marine sector under his belt, brings knowledge from his experience operating various ships as a seafarer and understanding of maritime regulations.

Having worked in the maritime sector for more than 30 years, marine safety investigator Khalled Jalil, 51, has a deep understanding of maritime regulations and how to operate various ships. ST PHOTO: SHINTARO TAY

Joining the TSIB seemed like a “natural progression” from his time at MPA, he said, as he wanted to conduct investigations that will bring safety benefits to seafarers everywhere.

TSIB investigations differ from MPA’s, in that TSIB investigators try to piece together what happened without placing blame, whereas the MPA’s job is to determine if laws have been broken. Mr Khalled said he likes the neutrality of the TSIB, which is focused solely on safety.

Rail probes

This is also the case for TSIB investigations of incidents involving Singapore’s MRT system.

Having worked for 11 years under public transport operator SMRT, TSIB rail safety investigator Lim Renwei made the switch to focus solely on rail safety investigations.

Lim Renwei keeps a lookout for rail incidents involving systemic errors across the board, and studies overseas investigation reports to share relevant lessons learnt with local rail operators. ST PHOTO: SHINTARO TAY

While TSIB’s rail team has not published any investigation report on Singapore’s rail system, it is assigned to keep a lookout for rail incidents involving systemic errors across the board and anomalies that affect the safe operation of the rail system.

An example is when a train passes a signal at danger – the equivalent of a car running a red light – without authorisation from the operations control centre.

A regular day at work for Mr Lim Renwei, 37, involves studying overseas investigation reports, engaging with stakeholders and overseas transport investigation counterparts, and sharing relevant lessons learnt from overseas incidents with local rail operators.

What else investigators do

Investigating incidents is a fraction of the work TSIB investigators do.

Its aviation investigators undergo training in various areas, ranging from survival in Arctic conditions of minus 35 deg C to simulations of high-altitude threats that pilots face such as decompression and hypoxia, which refers to low oxygen levels in a person’s body tissues.

In Arctic survival training, investigators spend more than 20 hours in the cold in the Arctic to learn how to start fires, chop wood, build shelters and keep themselves warm.

As aircraft accidents can take place anywhere, Mr David Lim noted that Arctic survival training was necessary for the team to be operationally deployable to overseas locations in all environments, including extreme weather conditions.

As for high-altitude threats, the team experienced these in a decompression chamber to better understand how pilots respond in such situations.

As TSIB has agreements with various countries to collaborate on aviation investigations, the team also participates in or observes overseas investigations that do not involve Singapore-registered aircraft.

Similarly, TSIB’s marine team organises internal safety training among mariners, regular equipment checks, and updates to electronic charts.

Mr Chong Chow Wah, director of TSIB and part of the air safety investigation team, told ST that the bureau’s investigators are drawn from diverse backgrounds with suitable educational and professional qualifications, and related industrial or investigative experience.

As TSIB investigators are cross-trained in other modes of transport, he added, investigators from other modes could be deployed to assist and collect evidence for a team specialising in another transport mode.

“At present, the staff strength is sufficient,” said Mr Chong. “However, a review of staff strength will be carried out when necessary to determine if there is a need to increase the number of investigators.”

On what his job is about, Mr Khalled told ST: “It’s about always maintaining your curiosity. Keep asking questions, keep looking, and you might eventually find the answer.”