An air traffic control officer in India has been suspended following an incident involving two airplanes' risky proximity to each other at the Chhatrapati Shivaji Maharaj International Airport in Mumbai on Jun. 8, 2024.

A video widely circulated online on Jun. 8 showed an Air India plane taking off, while an IndiGo plane landed closely behind, sparking safety concerns.

The officer was de-rostered by the Directorate General of Civil Aviation (DGCA) for negligence, reported India English-language newspaper Hindustan Times.

Airplanes were only 509m apart

A video of the incident shared on X showed the two planes' risky proximity when the IndiGo plane made its landing seconds before the Air India plane took off.

The Air India flight was taking off to Thiruvananthapuram, the state capital of Kerala, while the IndiGo plane had landed from Indore, a state within the Madhya Pradesh.

Woh, this looks real close.@IndiGo6E lands just when @AirIndia was taking-off at Mumbai Airport.@DGCAIndia @FAANews @CSMIA_Official @MoCA_GoI pic.twitter.com/wRtFiTLKHE

— Tarun Shukla (@shukla_tarun) June 9, 2024

The airplanes were 509m away from each other, according to flight tracking service Flightradar24 Jun. 9.

They reportedly experienced loss of separation while both planes were actually cleared for landing and take-off simultaneously, Flightradar24 wrote in an X post on Jun. 10.

Data also indicated that the two planes were 511m apart when the Air India plane started lifting off.

Yesterday in Mumbai, an Air India and IndiGo flight experienced a loss of separation when the Air India flight was cleared to depart and the IndiGo flight cleared to land. Here’s what the ADS-B data tells us about the proximity of the aircraft. https://t.co/ynhwr1pCLw pic.twitter.com/O1ccRpJn39

— Flightradar24 (@flightradar24) June 9, 2024

Staff suspended, authorities investigating

Following the incident, the DGCA has taken action against and de-rostered the air traffic control officer and staff for their negligence.

An investigation is also underway to understand the circumstances that resulted in the safety breach, reported Hindustan Times.

According to an Air India statement seen by The Times of India (TOI), the airline said its plane was cleared to enter the runway and to take off by the air controller.

An IndiGo spokesperson told India media that its pilot was also given clearance by the officer to land.

Air safety expert Amit Singh, who spoke to TOI, said a domino effect had been "triggered" by the Air India plane.

"The Air India aircraft was slow to take-off after it receive the line-up clearance, assuming they received immediate take-off clearance," he told TOI.

The pilot should have then informed the air traffic controller, who would be required to cancel the take-off clearance.

According to Mumbai airport Aeronautical Information Publication, controllers who observe delays in take-off as soon as clearance is given must cancel the take-off clearance and instruct the relevant airplane to vacate the runway immediately at the nearest taxiway for safety reasons.

Top screenshots via @shukla_tarun/X