Taipei, Taiwan – As the investigation into the fatal crash of Jeju Airlines Flight 2216 continues into its third day, aviation experts are raising questions about what role the concrete structure at the end of the runway at Muan International Airport in South Korea may have played in the accident, among other things. factors.

The Boeing 737-800 crashed into a concrete dam and burst into flames after being forced to make an emergency landing on Sunday morning, killing 179 of the 181 people on board in the worst plane crash ever on South Korean soil.

The pilot had informed air traffic control of a bird strike moments before the plane crashed on the runway after failing to deploy the landing gear and exceed the landing zone.

South Korean authorities said the concrete dam, which houses a local antenna to help pilots maintain the correct approach path, was built in accordance with regulations and was similar to other structures at airports around the world.

However, some aviation experts have questioned the choice and location of the structure, suggesting that the disaster might have been avoided through better airport design.

Najm al-Din Mishkati, a professor of civil engineering at the University of Southern California, said the use of concrete instead of metal towers or the installation of columns was “unusual” and may have contributed to the high death toll.

“This steel structure proved disastrous when the glider hit,” Mishkati told Al Jazeera.

“There is no doubt that if the aircraft had faced the airport wall, which would have provided less resistance, the survival rate would have been higher.”

Hassan Shahidi, president and CEO of the Aviation Safety Foundation, said that while he would not speculate on whether the dam was poorly designed or placed, structures at the end of runways must be built so that they break easily in the event of a collision under international civil aviation. . Organization guidelines.

“The standards also specify how close these structures are near the ends of the runway. Investigators will examine the concrete structure at the end of the runway to determine if it conforms to these standards, including its placement and proximity to the end of the runway,” Shahidi told Al Jazeera.

South Korean officials said the structure was 250 meters from the end of the runway, closer than the standard best practice of 300 metres, according to John Cox, a former 737 pilot who runs aviation consulting firm Safety Operating Systems.

Experts also questioned whether the runway had a suitable overtaking area or, as is the case at other airports with limited space, should have implemented an “engineered material prevention system” – also known as “EMAS” – capable of slowing or stopping the aircraft with momentum. Excessive.

Some advanced airports have areas after the runway that use sand, gravel or other aircraft-slowing material to reduce the plane’s speed and avoid a hard collision, said Dane Williams, director of aviation safety consulting firm Asia.

“In more developed countries, this mitigation is being put in place at the end of runways where possible, where appropriate, where economically viable,” Williams told Al Jazeera.

“It is also understood that if there is a large lake, river or other geophysical location such as a valley at the end of the runway, a physical concrete barrier may be suitable.”

Other airport design features have also come under scrutiny.

Marco Chan, a pilot and senior lecturer in flight operations at Buckinghamshire New University, said choosing a runway with a -0.2% descent slope raised “more questions about its suitability for emergency landings”.

“Investigators will explore whether this decision took into account the weather conditions, which were calm… or whether other operational considerations influenced it,” Chan told Al Jazeera.

South Korean investigators, with the help of officials from the US National Transportation Safety Board, are examining a range of possible scenarios, including bird strikes and aircraft systems failure.

Initial findings on the cause of the disaster are unlikely to be published for weeks. The investigation likely will not confirm some or all of the theories raised by officials and analysts.

“When you’re investigating, you’re not just looking at the plane,” Anthony Brickhouse, a veteran US-based aviation safety expert, told Al Jazeera: “You’re looking at the human element, meaning you’re looking at the pilots, you’re looking at air traffic control, you’re looking at maintenance, and then You look at the machine.”

“What happened to that plane that prevented them from lowering the landing gear?”

While bird strikes have been blamed for contributing to a number of aviation accidents, including the fatal 2019 crash of Ethiopian Airlines Flight 302, a collision with a bird is unlikely by itself to bring down a modern aircraft, according to aviation experts.

More than 13,000 bird strikes are reported to ICAO each year, and only a small fraction of these result in aircraft damage or flight interruptions.

In the case of Flight 2216, investigators will examine whether the bird could have damaged critical systems, such as engines and hydraulics, leading to “cascading failures, including hydraulic problems or an inability to deploy the landing gear,” Chan said. “.

Analysts were particularly puzzled by the speed at which the plane descended and its failure to deploy its landing gear.

Video footage of the disaster also showed that the nose of the plane never fell completely before the plane went out of frame and exploded.

“Video footage indicates that the aircraft was approaching at a relatively high speed, raising questions about whether the aircraft was properly prepared for landing or whether system malfunctions were preventing key deceleration mechanisms from operating,” Chan said.

It was also notable from footage of the incident that the plane touched down on the runway, Brickhouse said.

“In a landing, friction will be your friend to slow you down. Unfortunately, it doesn’t appear that the plane was on the runway long enough to slow down,” Brickhouse said.

South Korea’s Ministry of Transport said on Tuesday that the “black box” flight recorder had been recovered from the crash site with key pieces missing and that authorities were reviewing how to extract the data.

The National Police Agency said it is deploying more personnel and using rapid DNA analysis to speed up the identification of accident victims while gathering family members at the airport to demand more information about their loved ones.

Acting South Korean President Choe Sang-mok has ordered an emergency safety inspection of the country’s entire aviation operations, while authorities separately conduct inspections of all Boeing 737-800 aircraft operating in the country.