SEOUL, May 24 (Reuters) - Singapore Airlines

has tweaked its in-flight seatbelt sign policies and altered at

least one flight route after a turbulence incident this week

killed one person and left dozens critically injured, according

to the airline and flight data.

The airline is adopting a more cautious approach to

turbulence, including not serving hot drinks or meals when the

seatbelt sign is on, it said in a statement to Singapore

broadcaster Channel News Asia.

"SIA will continue to review our processes, as the safety of

our passengers and crew is of utmost importance," it said.

The airline did not respond to a Reuters request for

comment.

The SQ321 London-Singapore flight on a Boeing

777-300ER plane carrying 211 passengers and 18 crew diverted to

Bangkok for an emergency landing on Tuesday after the plane was

buffeted by turbulence that flung passengers and crew around the

cabin, slamming some into the ceiling.

The daily London to Singapore route SQ321 has completed two

flights since the incident and not flown over the part of

Myanmar where the sudden turbulence occurred about 3 hours

before scheduled landing. The flight time is about the same,

tracking data show.

They flew instead over the Bay of Bengal and Andaman Sea,

route data from flight tracker FlightRadar 24 shows.

Singapore Airlines has said the plane on Tuesday encountered

sudden extreme turbulence. A 73-year-old British passenger died

of a suspected heart attack.

Photographs from inside the plane showed gashes in the

overhead cabin panels, oxygen masks and panels hanging from the

ceiling and luggage strewn around. A passenger said some

people's heads had slammed into the lights above the seats and

broken the panels.

As of late Thursday, 48 passengers and two crew members

were hospitalised in Bangkok; 19 others were still in Bangkok,

the airline said.

Twenty of the 48 remained in intensive care, an official at

Bangkok's Samitivej Srinakarin Hospital said on Thursday, adding

that the injured had a mix of spinal cord, brain and skull

injuries.

Singapore Airlines, which is widely recognised as one of the

world's leading airlines and is seen as a benchmark for much of

the industry, has not had any major incidents in recent years.

TURBULENCE

A spate of turbulence reports has triggered a

debate

over whether climate change may be causing an uptick. A

report from the University of Reading last year suggested

turbulence could worsen with climate change.

Professor Paul Williams, one of the authors, has said

more research is needed to understand the impact of climate

change on air turbulence.

Technological advances have helped limit the number of

turbulence-related fatalities, which have significantly

decreased in the past 20 years.

Airlineratings.com Editor-in-Chief Geoffrey Thomas said

some airlines may change their

policy

on wearing seatbelts as a result of the incident.

Airlines are required by law to switch on the seatbelt

sign during takeoff and landing, but carriers have their own

procedures to deal with midair turbulence.

"I think this incident will prompt airlines, whether

it's an official mandate or not. But airlines saying 'we

recommend you keep your seatbelt fastened while seated', should

be saying it is mandatory to keep your seatbelt done up," Thomas

said.