The Boeing 737-8 Max will not be used for commercial operations in Singapore until the authorities are satisfied that all safety concerns about the aircraft have been addressed.
The Civil Aviation Authority of Singapore (CAAS) on Thursday said it has given SilkAir - the regional arm of Singapore Airlines (SIA) Group - a permit to fly the plane back to Singapore for retrofitting and upgrading.
But this does not constitute approval for a return to service, it said.
It issued the statement a day after the first of six SilkAir Boeing 737-8 Max planes returned from the Alice Springs aircraft storage facility in Australia.
The planes had been grounded since March 2019, following two fatal accidents involving the aircraft in less than five months. They were subsequently flown to the Alice Springs facility.
CAAS deputy director-general Tay Tiang Guan said the authority is currently reviewing the aircraft's airworthiness.
"As part of this review, CAAS will consider the United States Federal Aviation Administration's requirements and will determine if there is a need to impose additional requirements before we lift the suspension on Boeing 737 Max operations."
The US Federal Aviation Administration had last November ended a 20-month flight ban on the aircraft. The 737 Max was grounded by aviation authorities worldwide after two crashes in Indonesia and Ethiopia killed 346 people within five months - from October 2018 to March 2019.
Following investigations, a faulty flight handling system known as the Manoeuvring Characteristics Augmentation System was identified as a principal cause in both crashes.
An SIA spokesman said on Wednesday that the safety of its customers and staff is the airline group's top priority.
She added: "We will continue to work with and be guided by our regulators on Boeing 737-8 Max operations."
Brazilian carrier Gol, the biggest domestic airline in Brazil, became the first carrier to resume commercial flights with the aircraft on Dec 9. American Airlines subsequently restarted 737 Max flights on Tuesday.
Toh Ting Wei