Hundreds attend memorials for 520 victims of Japan Airlines jumbo jet crash 30 years ago

 Relatives of victims of the Japan Airlines (JAL) Flight 123 crash offer prayers at a memorial for the 30th anniversary of the accident on Aug 12, 2015.
Relatives of victims of the Japan Airlines (JAL) Flight 123 crash offer prayers at a memorial for the 30th anniversary of the accident on Aug 12, 2015.PHOTO: AFP

TOKYO (AFP) - Hundreds of people attended ceremonies on Wednesday marking the 30th anniversary of a Japan Airlines (JAL) jumbo jet crash that killed 520 people on board, the deadliest single-aircraft disaster in history.

The doomed Boeing 747 had begun the hour-long flight from Japan's capital to Osaka when it crashed into a mountain about 120km north-west of Tokyo on Aug 12, 1985.

In all, 509 passengers, including a dozen infants, and 15 crew were killed in the accident. Just four passengers survived.

Bereaved relatives of victims make an annual pilgrimage to Osutaka Ridge, along with JAL president Yoshiharu Ueki who will walk the trail to a memorial service near the crash site.

Ahead of Wednesday's events, Mr Ueki told local media that "we would like to learn a lesson from this accident without forgetting the memory" of the lives lost.

Television footage showed some victims' relatives starting their climb up the steep mountain trail before dawn.

Some blew soap bubbles to pay tribute the children who died in the accident, their names included on a stone memorial listing the victims.

"When I come here I feel like I can see her directly - it's like she's in front of me," an 81-year-old man who lost his daughter told local media.

"Thirty years is a long time, but honestly I feel as if it happened yesterday, and the memories were stirred again this particular year."

Japan Airlines Flight 123 took off from Tokyo's Haneda Airport at 6.12 pm local time and quickly ran into trouble, with a loud noise heard about 10 minutes into the trip.

The crew quickly declared an emergency and fought to regain power over the aircraft which had become "uncontrollable".

It crashed into the mountain at 6.56 pm local time, about 45 minutes into the flight.

It was later determined that the bulkhead burst, rupturing hydraulic systems and leaving the plane uncontrollable.

A government-appointed investigation panel blamed the accident on improper repairs on the rear bulkhead seven years earlier.

In 1988, local police served papers on 20 people from JAL, the transport ministry and Boeing on suspicion of professional negligence resulting in death and injury.

But prosecutors decided not to indict anyone.

"It can never be forgotten," Mr Satoshi Iizuka, a former police officer who identified bodies at the site three decades ago, told broadcaster TV Asahi as he choked back tears.

"Today, people tend to prioritise speed over safety."

This year's anniversary comes several days after the hunt for more wreckage from missing Malaysia Airlines flight 370 resumed on France's Reunion island in the Indian Ocean after being suspended last week.

A wing part was found on the island in late July and confirmed by the Malaysian prime minister to be part of the Boeing 777 that disappeared on March 8, 2014 with 239 people onboard.