Police investigators look into the scene of a deadly crash of a Jeju Air passenger jet at Muan International Airport, South Jeolla Province, Monday. Yonhap

A fatal crash of a Jeju Air passenger jet has sparked controversy over whether greater responsibility lies with the low-cost carrier (LCC) or Boeing, the manufacturer of the ill-fated 737-800 aircraft.

The jetliner, carrying 181 passengers and crew, crashed into a concrete wall on Sunday morning while making an emergency landing at Muan International Airport in South Jeolla Province due to a landing gear malfunction. The deadly incident claimed 179 lives, leaving only two survivors — both crew members.

Even though an investigation is still underway to determine the exact cause of the accident, all eyes are focused on assigning accountability for what is now the deadliest aviation disaster in Korea's history.

Adding to the controversy, just one day after the tragedy, another Boeing 737-800 operated by Jeju Air, which had departed from Gimpo International Airport, was forced to return due to the same landing gear issue. This incident has intensified speculation that the airline's poor maintenance may have played a role in the earlier accident.

However, Jeju Air rejected the allegations of inadequate aircraft maintenance, insisting that it places the utmost priority on ensuring the safety of its aircraft.

"We cannot agree with any argument that our maintenance environment remains poor," Song Kyung-hoon, head of the airline's management support office, told reporters on Sunday afternoon.

"Jeju Air has never skipped any procedures on maintenance, nor did we make light of safety."

Addressing the Monday incident, Song stated, "We identified the landing gear malfunction after takeoff, but the plane returned to normal operation shortly thereafter. However, the captain decided to return to ensure safety."

In 2022, a Jeju Air aircraft, which departed from Kansai International Airport in Japan, had to return shortly after takeoff due to an engine failure caused by a bird strike. However, a post on Blind, an anonymous community app for office workers in Korea, written by someone claiming to be a Jeju Air employee, sparked controversy by alleging that the carrier had covered up the engine failure as a bird strike.

However, Jeju Air CEO Kim E-bae said the two aircraft malfunctions were not related.

A firefighter checks carriers and bags of passengers from a Jeju Air passenger jet that burst into flames during landing, Sunday, at Muan International Airport, South Jeolla Province, Monday. Yonhap

On the other hand, some argue that Boeing is to blame for the latest incident, pointing to repeated reports of malfunctions involving the aircraft model around the world.

Another Boeing 737-800 passenger jet, operated by KLM, made an emergency landing after experiencing a hydraulic failure on its flight from Oslo, Norway to Amsterdam, the Netherlands, Sunday (local time).

The 737-800 has also faced similar landing gear issues in India and the United Kingdom.

The aircraft is one of the best-selling models for Boeing. Most LCCs here, such as Jeju Air, T'way Air, Jin Air and Eastar Air, operate the aircraft.

There are a total of 101 737-800s in operation in Korea: 39 by Jeju Air, 27 by T'way Air, 19 by Jin Air, 10 by Eastar Jet, four by Air Incheon, and two by Korean Air.

In response to the concerns, Korean authorities initiated a special inspection of local carriers to determine whether they are adhering to maintenance regulations for the 737-800 model.

"We will conduct comprehensive safety inspections on the model's maintenance reports and scrutinize whether each carrier complies with aviation maintenance regulations," an official from the transport ministry said.

Hit by the involvement in the deadly crash, Jeju Air suffered a steep fall in its stock value. Shares of the LCC plummeted more than 15 percent on Monday morning.