*

Identification of crash victims expedited by South Korean

police

*

U.S. NTSB joins investigation into Jeju Air crash

*

Runway design criticized for contributing to crash

severity

(Recasts throughout, adds quotes and details, bullet points)

SEOUL, Dec 31 (Reuters) -

Questions grew on Tuesday over the crash of a Jeju Air

jetliner as police rushed to identify victims and as families of

those killed in the

deadliest plane crash

on South Korean soil pressed authorities for more

information.

The National Police Agency said it is making all-out efforts

by adding personnel and rapid DNA analysers to shorten the

identification period. Five bodies remained unidentified as of

Tuesday.

Family members gathered at the country's Muan International

Airport, where the crash occurred, have pushed for faster

identification and more information from authorities.

All 175 passengers and four of the six crew were killed when

a Jeju Air Boeing 737-800 belly-landed and

skidded off the end of the runway, erupting in a fireball as it

slammed into a wall. Two crew members were pulled out alive.

South Korea's acting President Choi Sang-mok on Monday

ordered an emergency safety inspection of the country's entire

airline operation as investigators sought to find out what

caused the deadliest air disaster on South Korean soil.

The Transportation Ministry said representatives from the

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

Aviation Administration, and aircraft manufacturer Boeing ( BA ) have

joined the investigative body and plan to meet in Muan on

Tuesday to discuss future schedule.

The U.S. team led by the NTSB is on the ground in South

Korea providing assistance, board chair Jennifer Homendy said in

an interview. The NTSB said in a statement it sent three

investigators including people with specialties in operational

factors and airworthiness to South Korea to assist the

investigation.

"If we need more specialists we will send them," Homendy

said.

Investigators are examining bird strikes, whether any of the

aircraft's control systems were disabled, and the apparent rush

by the pilots to attempt a landing soon after declaring an

emergency as possible factors in the crash, fire and

transportation officials have said.

Officials have also faced pointed questions about design

features at the airport, particularly a large dirt-and-concrete

embankment near the end of the runway used to support navigation

equipment.

The plane slammed into the embankment at high speed and

erupted into a fireball. Bodies and body parts were thrown into

surrounding fields and most of the aircraft disintegrated in

flames.

South Korean officials say the embankment was built

according to standards, and that there are similar features at

other airports including in the United States and Europe.

But many experts said its proximity to the end of the runway

defied best practices and likely made the crash far more deadly

than it may have been otherwise.

The runway design "absolutely (did) not" meet industry best

practices, which preclude any hard structure like a berm within

at least 300 metres (330 yards) of the runway's end, said John

Cox, CEO of Safety Operating Systems and former 737 pilot.

The airport's concrete berm appears to be less than half

that distance from the end of the pavement, according to

Reuters' analysis of satellite images.

South Korean officials have said it is about 250 metres from

the end of the runway itself, though a paved apron extends past

that.

The plane appeared in video footage to be slowing down and

in control when it went off the runway, Cox said. "When it hits

that berm is when it turns into tragedy."

(Reporting by Hyonhee Shin, Jihoon Lee, Joyce Lee and Hyunsu

Yim in Seoul, Dan Catchpole in Seattle, David Shepardson in

Washington; Writing by Josh Smith; Editing by Tom Hogue and

Lincoln Feast.)