Petaling Jaya, Malaysia: The Learjet 60 and Gulfstream IV aircrafts belonging to businessman Datuk Seri Tiong King Sing are high-end private jets, aviation experts said.

They said the cost could vary depending on the whether it is was bought “off the rack” from manufacturers or were custom-made to include additional comfort fittings or avionics.

New planes, they said, would cost between US$15 million ($21 million) and US$40 million each.

If the aircraft were bought second-hand, the price would be lower. However, there is no fixed rate for them in the second-hand market.

They said both planes required qualified and specialised crew.

Each plane would require two pilots. The monthly salaries of pilots could be estimated to be RM20,000 ($8,190) each.

“Such pilots are usually expatriates,” one of them said. As for inflight crews, how many were employed would depend on the requirements of the owner.

As for maintenance, both planes required special expertise.

They said there were limited personnel in Malaysia to maintain the aircraft and they would most likely have to be serviced in Singapore.