SEOUL, Jan 3 (Reuters) - South Korea's transport

ministry has extended special inspections of all 101 of the

Boeing 737-800 jets run by the country's airlines by a week,

after the worst aviation disaster on the country's soil, a

ministry official said on Friday.

The ministry launched the inspections following Sunday's

crash of a Boeing 737-800 operated by Jeju Air that

killed 179 people. The inspections were supposed to be completed

on Friday but were extended to Jan. 10, the official told

Reuters, without elaborating on the reason.

The Jeju Air flight from Bangkok to Muan county in

southwestern South Korea belly-landed and overshot the regional

airport's runway, exploding into flames after hitting an

embankment.

The ministry has said it would look at engines, maintenance

records and landing gear on all 737-800s, and an airline's

operations could be suspended for serious violations.

The transport ministry also held an emergency meeting with

chief executives of 11 airlines, including top-ranked Korean Air

Lines and Asiana Airlines, to discuss

measures to enhance aviation safety, the ministry official said.

South Korea's investigation team said on Friday two of its

members would leave for the United States next week to analyse

the flight data recorder of the crash in cooperation with the

U.S. National Transportation Safety Board (NTSB).

The team is also studying the plane wreckage and

interviewing airport control tower officials.

Investigators will analyse data on 107 mobile phones

recovered from the crash site, including text messages, for

clues on what happened leading up to the crash, Yonhap News

said.

South Korean acting President Choi Sang-mok on Friday urged

investigators to work swiftly to collect evidence from the crash

scene and analyse a voice recorder.

Unanswered questions include 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.

Police said on Thursday they were searching Jeju Air and the

operator of Muan International Airport and banned Jeju Air chief

executive Kim E-bae and another unidentified official from

leaving the country.