IndiGo has derostered two pilots and four cabin crew members of the Delhi-Varanasi flight that saw 176 passengers being evacuated after a bomb threat earlier this week, according to sources.

On May 28, following the bomb threat, which later turned out to be hoax, all the passengers were evacuated through emergency slides from the aircraft at the Delhi airport.

In a video clip of the evacuation that went viral on social media, a pilot was seen coming out of the aircraft through the emergency slide with a baggage. Under international norms, passengers and crew are not permitted to take their baggage at the time of evacuation as that will increase the time for evacuation.

The wet-leased aircraft was to operate the flight from the national capital to Varanasi on the morning of Tuesday (May 28).

One of the sources said the two pilots, who were from the lessor company, four IndiGo cabin crew members have been derostered.

Generally, under the wet lease arrangement, crew, insurance and other things related to the aircraft are taken care of by the lessor.

A source at the Directorate General of Civil Aviation (DGCA) confirmed that the crew have been derostered.

Specific details regarding the derostering could not be immediately ascertained.

"Safety is our prime concern and our crew acted accordingly in the best interest of our customers safety. As with all safety & security events our flight safety team will be reviewing this as well," an IndiGo spokesperson said in a statement.

The review pertains to multiple things that are being investigated by the flight safety team.

A senior commander, who has flown wide-body planes for many years, told PTI that during an emergency evacuation, passengers are not allowed to take their baggage and also footwear with heals should be avoided as they can puncture the emergency slides that are inflated.

Also, carrying the baggage will increase the time for evacuation. Under the international norms, a flight evacuation has to be completed in 90 seconds using the emergency exits.

A senior cabin crew of another carrier who was part of an emergency evacuation earlier told PTI that the basic instruction to passengers during the emergency evacuation is to leave everything behind.

Carrying baggage will not only delay the evacuation but could also puncture the inflated emergency slides. Crew members of the flight are also not permitted to carry their baggage, he said.

As per information available on website SKYbrary, aircraft manufacturers are required to demonstrate that an aircraft, in maximum density configuration, can be completely evacuated within 90 seconds using only half of the total number of emergency exits.

"Ninety seconds has been established as the maximum evacuation time because tests have shown that, in a post crash fire, conditions conducive to flashover are unlikely to occur within that time span.

"However, the experience of actual evacuations, especially unexpected ones from full aircraft where the abnormal situation occurs suddenly at or soon after landing, indicates that evacuation times usually exceed durations demonstrated for certification purposes," it said.

SKYbrary is an electronic repository of information related to flight operations, air traffic management and aviation safety in general.

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