Perturbed with the preliminary findings of the AAIB inquiry into the Ahmedabad plane crash, Pushkaraj Sabharwal, father of Captain Sumeet Sabharwal who was one of the pilots of the Air India Dreamliner, has demanded a 'formal investigation' by the central government.

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In one of the worst aircraft accidents in India, a total of 260 people, including 241 passengers, died after Air India's Boeing 787-8 aircraft operating flight AI171 to London Gatwick crashed soon after take off from Ahmedabad on June 12.

In a letter to the civil aviation secretary and AAIB Director General, 91-year-old Pushkaraj said that selective leaks about the accident have led to speculation that Sumeet (56) was under tremendous psychological pressure and therefore was contemplating death.

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"These innuendos have very adversely affected my health and mental setup and the reputation of Captain Sumeet Sabharwal. They tarnish Captain Sabharwal's reputation, which is a fundamental right guaranteed to a citizen of India under Article 21 of the Constitution of India," the letter, dated August 29, said.

Pushkaraj has demanded that the central government order a formal enquiry into the accident under Rule 12 of the Aircraft (Investigation of Accidents and Incidents) Rules, 2017.

Under Rule 12, the central government can institute a formal investigation into circumstances of any accident of an Indian registered aircraft if it appears that it is expedient to hold such a probe.

There were no immediate comments from the Civil Aviation Ministry and the Aircraft Accident Investigation Bureau (AAIB) on the letter.

Amid speculations about the cause of the fatal crash after the release of its preliminary probe report on July 12, AAIB had asserted that it was too early to draw any "definite conclusions" on what led to the accident as the investigation was still on and that the final report will come out with the root causes. The probe agency had also urged everyone to refrain from spreading premature narratives.

"The preliminary report on the contrary does not allude to the 'what' happened or the bare facts of the crash, instead resorting to insinuations on the one hand and offering copious clean chits to the manufacturer/s on the other. The report in its present form is deficient, diversionary & discrepant," the letter said.

It also claimed that selective information of the preliminary investigation has been put out in the public domain and the material gathered during such investigation has been released which include the contents of the cockpit voice recorder.

Pushkaraj also refuted speculations about the mental health of his son.

Citing reports, he said it was suggested that Sumeet was divorced and that caused him anxiety and depression.

"It even ignores the fact that Captain Sabharwal was divorced about 15 years ago. The other speculation relating to the cause for Captain Sabharwal being desirous of committing suicide has been his mother's death. His mother died more than three years ago. After that, Captain Sabharwal had operated more than 100 flights without any incident or accident.

"It is most pertinent to note that in over 25 years of flying, Captain Sabharwal had not had a single incident or accident-causing fatalities or otherwise," the letter said.

He had almost 15,638.22 hours of flying experience out of which 8,596 hours were on the 787-8 aircraft. He was also designated as a Pilot Trainer i.e a Line Training Captain and had the DGCA licence for the purpose.

Pushkaraj also said that the absence of a formal enquiry conducted in accordance with Rule 12 coupled with the selective information being provided to the media is very disturbing/detrimental to him and affects his fundamental rights, including the right to reputation of his deceased son.

Under Rule 12 of the Aircraft (Investigation of Accidents and Incidents) Rules, 2017, the central government can institute a formal investigation into circumstances of any accident of an Indian registered aircraft if it appears that it is expedient to hold such a probe. This will be in addition to the AAIB probe.

In the preliminary report, AAIB had said the fuel supply to both engines of the plane was cut off within a gap of one second, causing confusion in the cockpit soon after takeoff. "In the cockpit voice recording, one of the pilots is heard asking the other why did he cut off. The other pilot responded that he did not do so," it had said.

Air India Ahmedabad plane crash: Pilot's father seeks another probe saying AAIB findings tarnished his son's image