SURABAYA (THE STAR/ASIA NEWS NETWORK) - Indonesia AirAsia is planning to retire its QZ8501 flight code following the disappearance of its aircraft en route to Surabaya to Singapore on Sunday.

Its chief executive Sunu Widyatmoko said, however, that the process may take time before it could take effect.

"We have forwarded our suggestion to the headquarters, but we are still waiting for the approval and coordination from the headquarters," he said.

Indonesia AirAsia Flight QZ8501, that took off from Surabaya's Juanda International Airport to Singapore's Changi Airport went off flight radar 42 minutes into its journey.

The Airbus A320-200 was flying in Indonesian airspace when it went missing, about 200 nautical miles south-east of the Singapore-Jakarta flight information region boundary.

One Malaysian was among 155 passengers confirmed, comprising 149 Indonesians, three South Koreans, and one each from Singapore and Britain.

Mr Sunu said although they were still "in shock", the budget carrier said they were supporting the affected families all they could.

"Our focus now from AirAsia is to support the next of kin to go through this very difficult time," he said.

Since the disappearance, Malaysia had deployed three vessels and three aircraft to assist in the search operations.

Surabaya-based Search and Rescue (SAR) head Hernanto said that the search would not be as extensive as the search for the missing Malaysia Airlines MH370, that was believed to have crashed into the southern Indian Ocean.

"Our search for the missing plane would not be as difficult as finding the Malaysia Airlines plane because we have the last coordinates of the contact," he said.

He also said that they were confident in finding the missing aircraft earlier than expected, now that the neighbouring countries have extended their assistance by deploying their assets.