Toks Desalu wrote:

Anybody know why they use this procedure. I thought this procedure
is banned due to ground deaths.

This is a common practice at a number of airports. It is called a
powerback. It is only performed on aircraft with fuselage-mounted
engines, since wing-mounted engines kick up too much junk from the
ground, and are susceptible to FOD.

The normal procedure is to power forward slightly to release the brakes,
then use the thrust reversers to power back. There is a limit to the
amount of reverse thrust they can use to avoid tipping the aircraft
around the main gear.

The advantage of powerbacks is economic: they reduce the need for tugs,
and ground crew.