South Korea launches safety inspection of all airline operations after Jeju Air crash

South Korea has launched an emergency safety inspection of the country’s entire airline operations, and a separate check of all Boeing 737-800s, after 179 people died in a Jeju Air crash involving the aircraft on Sunday.

As shocked citizens began a second day of official mourning and flags flew at half-mast, the government said it would carry out the audit of all 101 of the aircraft in domestic operation, with US investigators, possibly including Boeing, joining the inspection.

Choi Sang-mok, who was appointed South Korea’s president two days before the disaster, said an exhaustive inspection was essential to overhaul the aviation safety system and “move toward a safer Republic of Korea”.

He was speaking as reports emerged that another passenger jet belonging to Jeju Air was forced to return to Gimpo airport in Seoul shortly after taking off on Monday, following an unspecified problem with its landing gear.

Landing gear malfunction is among the issues being targeted by the investigation into Sunday’s crash, in which the plane skidded along the runway in what the aviation industry describes as a “belly landing”.

Officials said the crash could have also been caused by a bird strike and weather conditions – or a combination of those and other factors – but the exact cause was not yet known. It was the worst civil aviation disaster on South Korean soil.

With identification of the dead proceeding slowly, Park Han Shin, a representative of the bereaved families, said they were told that the bodies were so badly damaged that officials needed time before returning them to their families.

“I demand that the government mobilise more personnel to return our brothers and family members as intact as possible more swiftly,” he said.

Among questions that have emerged in the immediate aftermath of the accident is whether an almost 2-metre-high structure, a concrete wall located unusually close to the end of the runway, which the jet hit before exploding, exacerbated the catastrophe.

The wall, used to support a “localiser” antenna that provides landing alignment information to aircraft, is understood to be much taller than those used at other South Korean airports.

Transport ministry officials said on Monday they would look into whether the Muan airport’s localiser should have been made with lighter materials that would have broken up more easily.

Two flight attendants – a man and a woman – were rescued from the tail of the aircraft, which broke apart upon impact with the wall. They were being treated at a hospital in Seoul after being transferred from hospitals near the airport, the Yonhap news agency said.

The male survivor was being treated for fractures to his ribs, shoulder blade and upper spine, said Ju Woong, the director of the Ewha Womans University Seoul Hospital. Ju said the man, whose name has not been released, told doctors he “woke up to find (himself) rescued”. Details of the female survivor were not immediately available.

The Boeing 737-800 plane operated by South Korean budget airline Jeju Air aborted its first landing attempt and later smashed down on the runway at speed after issuing a distress call.

Video of the crash indicated that the pilots did not deploy flaps or slats on the wings to slow the aircraft, suggesting a possible hydraulic failure, and did not manage to manually lower the landing gear, possibly as they did not have time.

The plane’s flight data recorder and cockpit voice recorder have been retrieved from the wreckage, but media reports said it could take longer than usual to determine the cause as the flight data recorder had been damaged in the crash.

Establishing the cause of a major air disaster typically takes months, and damage to the recorder was expected to cause further delays, Yonhap said, citing a land ministry official.

Choi declared a seven-day mourning period starting Sunday, as he attempted to coordinate a response to a major disaster only days after he replaced his impeached predecessor, Han Duck-soo.

Han, too, had been made interim leader after the impeachment in mid-December of Yoon Suk Yeol over his disastrous, and short-lived, declaration of martial law earlier in the month.

The animosity of the past month appeared to have been put to one side as senior politicians from the ruling and opposition parties attempted to console a country in mourning.

While the accident investigation will focus on the model of aircraft, there will inevitably be questions for the flight’s operator, Jeju Air.

Related: US sends investigators to help establish cause of South Korea plane crash

The low-cost carrier said it would do all it could to support the families of the victims, including with financial aid.

Its chief executive, Kim E-bae, told a televised news conference he took “full responsibility” for the crash, irrespective of the cause, and bowed deeply in apology with other senior company officials.

He said the company had not identified any mechanical problems with the aircraft following regular checkups and that he would wait for the results of government investigations.