European aviation giant Airbus was sending experts to New Delhi on Tuesday to assist domestic investigators probing an Air India flight that plunged dramatically, injuring 17 in a terrifying mid-air ordeal, the company said.

The probe into the flight comes as "confirmatory" psychoactive drug test results are awaited for the chief pilot.

The Airbus A320, carrying 137 passengers and eight crew, lost around 300 feet (91 meters) on Aug. 4 while flying from Phuket in Thailand to New Delhi, before stabilizing and landing safely.

Air India, in a statement after the plane landed, said it had "experienced a sudden loss of altitude," adding that it was "fully cooperating with the investigation, and the aircraft manufacturer has also been notified."

India's civil aviation ministry said that the "occurrence has been classified as a Serious Incident and is under investigation by the Aircraft Accident Investigation Bureau (AAIB)."

An Airbus spokesperson said that the jet manufacturer was providing "technical assistance" to the Indian investigating authorities.

Indian newspapers have widely reported that the flight experienced several technical snags just before it experienced a sudden loss in altitude, but neither the carrier, Indian authorities, or Airbus have provided official confirmation.

"A team of specialists is being dispatched to assist with the investigation," an Airbus spokesperson said on Monday.

"Airbus is providing technical assistance to the relevant investigating authorities. We are actively supporting the airline and will provide further information as it becomes available," they added.

Air India has said it "cannot comment on any findings or observations related to the investigation."

Reuters reported on Tuesday that India's civil ​aviation minister has summoned Air ​India CEO ⁠Campbell Wilson after ⁠the airline's Phuket-Delhi flight incident, a ​source ⁠with direct knowledge of the matter said.