"Weather along the way is quite swee, but to be safe, please kiap your seatbelt tight, hor."

Travellers returning to Singapore this National Day will hear this message telling them to buckle up or other announcements sprinkled with Singlish on selected Jetstar flights this National Day.

The budget airline will use Singlish - the national slang - to make in-flight service announcements on Aug 9 as part of the airline's National Day celebrations.

These include announcements on, say, duty-free sales: "Later we'll also be coming around for duty free. If you haven't buy from the airport yet, then you can buy from us lah. All same price, confirm plus chop".

Singlish lines will be provided to the crew, but they are free to add their own flair to the announcements, a Jetstar Asia spokesman told The Straits Times.

It is implementing this initiative following the success of an April Fools' video the airline posted online which showed Jetstar staff in classrooms learning how to make flight announcements in Singlish.

"Singlish is a part of Singapore's identity and heritage so we hope the public will see this as a fun celebration of local culture on National Day," the airline said.

But pre-flight safety demonstrations and announcements will still be made in standard English.

Associate Professor of English Literature at Singapore Management University Kirpal Singh said Singlish is a key component of the Singaporean identity.

"Whenever Singaporeans are abroad, one of the clearest markers of identity is, in fact, hearing somebody speak Singlish," he said.

He downplayed the possibility that delivering announcements in Singlish might give foreigners the impression that Singaporeans do not know how to speak accurate English.

"It doesn't really matter what others think because the majority of Singaporeans who use Singlish are actually very at home with good, proper, formal English as well," he said.