A frightening sensor malfunction on a Toronto-bound Air Canada flight in August instructed pilots to "pull up" in order to avoid a terrain despite cruising at an altitude of approximately 30,000 feet. 

On the night of Aug. 27, Air Canada Flight 43 departed from Indira Gandhi International Airport in Delhi, and was due to arrive at Toronto Pearson International Airport around 14.5 hours later. 

Following a brief delay on the ground, the Boeing 777-200 took off from Delhi with 316 passengers on board.

However, about an hour into the journey, the flight crew received "Terrain! Terrain! Pull up!" ground proximity warning system (GPWS) warnings despite cruising at an altitude of 30,000 feet — indicating a sensor malfunction. 

Pilots on board went through all the safety protocols and related checklists, but ultimately decided to cut the trip short and return back to the Delhi airport. 

Although the situation could've turned out differently had the warning been given at a lower altitude, the aircraft landed safely back in Delhi about two-and-a-half hours after departure. 

According to the Aviation Herald, the Transportation Safety Board of Canada (TSB) reported that emergency services met the aircraft on the runway, examined it, and it was eventually taxied to the apron. 

This isn't the first time an Air Canada flight has made headlines in the past few weeks. The airline recently sparked outrage and widespread criticism after two passengers were escorted off a Montreal-bound flight on Aug. 26 after objecting to sit in vomit-smeared seats. 

Last week, the airline apologized to the passengers and the Public Health Agency of Canada has since launched a probe into the incident.