Following the incident, the aircraft was taken out of service and is undergoing detailed maintenance inspections. IndiGo said the aircraft will return to service only after the necessary inspections and clearances have been completed. India's aviation regulator, the Directorate General of Civil Aviation (DGCA), has also begun investigating the incident.
So, what is a tail strike?
A tail strike occurs when the rear underside of an aircraft makes contact with the runway during take-off or landing. Although aircraft are designed to withstand certain levels of contact, a tail strike can potentially cause structural damage to the aircraft's rear fuselage or other components. For that reason, an aircraft involved in a suspected tail strike is normally removed from service and thoroughly inspected before flying again.
The Airbus A321, being the longest member of the A320 family, has a relatively small margin between its normal landing attitude and the angle at which the rear fuselage can contact the runway. Tail strikes can also occur during a go-around, when an aircraft rapidly changes its attitude and begins climbing after the crew has decided that a landing cannot safely be completed.
Airbus has previously highlighted the increased risk of a tail strike when a go-around is initiated close to the ground. The Bengaluru occurrence also comes after another IndiGo A321 was involved in a tail-strike incident at Gorakhpur approximately only a month earlier. That aircraft had conducted a go-around during its approach before landing safely. Subsequent inspection reportedly found minor damage around the tail area.
Another reminder that even a routine landing can involve a highly demanding sequence of decisions and actions by an airline's flight crew.