*

Police hunt for aircraft operation, maintenance data at

Muan

airport, Jeju Air office

*

Cockpit voice recorder data conversion to audio files

expected

to be completed on Friday

*

Rigid structure near end of runway "concerning",

engineering

professor says

(Rewrites throughout with police search)

By Hyunjoo Jin and Jihoon Lee

SEOUL, Jan 2 (Reuters) - South Korean police said on

Thursday they had raided Jeju Air and the operator

of Muan International Airport as part of their investigation

into Sunday's crash that killed 179 people in the worst aviation

disaster on the country's soil.

Jeju Air 7C2216, which departed the Thai capital of Bangkok

for Muan in southwestern South Korea, belly-landed and overshot

the regional airport's runway, exploding into flames after

hitting an embankment.

Two crew members, who were sitting in the tail end of the

Boeing 737-800, were pulled alive by rescuers but injured.

Police investigators are searching the offices of the

airport operator and the transportation ministry aviation

authority in the southwestern city of Muan, as the well as

office of Jeju Air in Seoul, the South Jeolla provincial police

said in a media statement.

Investigators plan to seize documents and materials

related to the operation and maintenance of the aircraft as well

as the operation of airport facilities, a police official told

Reuters.

A Jeju Air spokesperson said the airline is checking the

situation. The airport operator company was not immediately

available for comment.

Questions by air safety experts on what led to the

deadly explosion have focused on the embankment designed to prop

up navigation equipment that they said are too rigid and too

close to the end of the runway.

"This rigid structure proved catastrophic when the skidding

aircraft made impact," said Najmedin Meshkati, an engineering

professor at the University of Southern California, adding it

was concerning that the navigation antenna was mounted on "such

a formidable concrete structure, rather than the standard metal

tower/pylon installation".

A probe into the Jeju Air flight is also under way involving

South Korean officials and the U.S. National Transportation

Safety Board (NTSB), Federal Aviation Administration (FAA) and

the aircraft's maker, Boeing ( BA ).

It remains unanswered why the aircraft did not deploy its

landing gear and what led the pilot to apparently rush into a

second attempt at landing after telling air traffic control the

plane had suffered a bird strike and declaring an emergency.

The aircraft's flight data recorder, which sustained some

damage, is being taken to the United States for analysis in

cooperation with the NTSB.

The conversion of data from the cockpit voice recorder

to audio file should be completed by Friday, acting President

Choi Sang-mok said, which could provide critical information on

the final minutes of the doomed flight.

A transport ministry official said on Wednesday it may be

difficult to release the audio files to the public as they will

be critical to the ongoing investigation.

Choi said in a disaster management meeting immediate

action must be taken if a special inspection of all Boeing

737-800 aircraft operated in the country finds any issues.

"As there's great public concern about the same aircraft

model involved in the accident, the transport ministry and

relevant organisations must conduct a thorough inspection of

operation maintenance, education, and training," Choi said.

Choi's comments at the start of the meeting were provided by

his office.

Investigators from the NTSB, FAA and Boeing ( BA ) are in South

Korea to help the probe.

Choi asked that no effort be spared in helping the

families of the victims as the remains of those killed are

handed over them. He also asked the police to take action

against anyone posting "malicious" messages and fake news on

social media related to the disaster.