The service from Bengaluru to Delhi, operated by Indian airline Go First, was due to depart at 6.20am on 9 January.
But passengers reported on social media that, despite arriving on time for flight G8 116, they were left behind.
Twitter user Shreya Sinha posted: “Most horrifying experience with @GoFirstairways.
“5.35am Boarded the bus for aircraft.
“6.30am, Still in bus stuffed with over 50 passengers, driver stopped the bus after being forced.
“Flight G8 116 takes off, leaving 50+ passengers. Heights of negligence!”
Satish Kumar posted an image of their boarding pass to show the flight details, including the assigned seat.
He tweeted: “Flight G8 116 (BLR - DEL) flew leaving passengers on ground! More than 50 passengers on one bus was left on ground and flight took off with just passengers of one bus on boarded.
“Is @GoFirstairways ... operating in sleep? No basic checks.”
Another passenger, Raktim Banik, tweeted: “Flight took off from Bengaluru as 54 passengers wait in bus! Is this a joke!”
A Go First representative responded: “We sincerely apologise for the inconvenience caused”.
A spokesperson reportedly said: “We have sought a report from the airline and appropriate action shall be taken afterwards.”
A Go First spokesperson told The Independent that affected passengers were accommodated on alternate airlines to Delhi and onward to other destinations.
They said: “We sincerely apologize for the inconvenience caused to the passengers due to an inadvertent oversight in the reconciliation of flight G8 116, from Bengaluru to Delhi.
“We deeply appreciate and value your patience for bearing with us. In line with our philosophy of customer centricity, the airline has decided to offer all affected passengers one free ticket for travel on any domestic sector in the next 12 months.
“The airline has initiated an inquiry into the incident and the matter is being investigated.
“All concerned staff off the roaster till the inquiry is going on.”
It’s not the first time travellers have been abandoned on the tarmac.
In April 2022 a group of Ryanair passengers were in disbelief after the airline appeared to forget about them, leaving them behind at the airport.
The mistake occurred when airport ground crew put passengers on airport shuttles to reach the aircraft, reports Balearic Islands newspaper Ultima Hora.
There was no room on the final bus, so the last group of travellers was told to wait for another shuttle.
However, the bus never returned – and in the meantime, the passengers were horrorstruck to realise the plane had taken off without them.