THE captain of the doomed Air India flight at the centre of a mental health probe was nicknamed “Sad Sack” in flight school, pals have revealed.

The latest analysis of the cockpit voice recording indicates it was Captain Sumeet Sabharwal who may have cut off the fuel supply to the engines of the Boeing 787 Dreamliner – causing a catastrophic loss of thrust.

With over 15,000 flying hours — more than 8,000 on the Dreamliner — Captain Sabharwal had long been considered steady and reliable.

His pals described him as soft-spoken and precise – and said he eventually earned the nickname of “Sad Sack” because of his serious demeanour.

The senior pilot is said to have lived a simple life with minimal belongings.

“He was a very reserved guy right from the beginning,” said fellow pilot Kapil Kohal.

“He was a middle-class boy looking at the sky and saying, ‘I want to be there,’” Kohal said.

He was driven by a sheer love of flying, Kohal said, and showed a flair for mentoring younger students.

But in recent years, Sabharwal is said to have faced personal struggles.

He was reportedly just months from retirement, grieving his mother’s death and caring for his elderly father.

The pilot had been considering leaving the airlines early to look after his elderly father, The Telegraph revealed.

Savitri Budhania, a neighbour of Captain Sabharwal, said the pilot told her: “Just one or two more flights… then I’m going to just be with Papa.”

Ms Budhania told the Times of India that Captain Sabharwal was a gentleman who would often take his father out for evening walks.

She added: “Whenever he wasn’t flying, you’d find him walking hand in hand with his father in the evening.”

Investigators are now said to be probing his medical records.

Sources familiar with the US officials’ assessment of the crash evidence told the Wall Street Journal that Captain Sabharwal reached out for the fuel cut switch.

A black-box recording of dialogue between him and first officer Clive Kunder revealed the junior pilot – who is thought to be in control of the flight at that stage – asked the more-experienced captain why he moved the switches to the “cutoff”.

The analysis also indicated that the first officer expressed surprise and then panicked.

While the captain of the flight – who was monitoring the operations and likely had his hands free – remained calm.

Early findings in a 15-page crash report released by the Indian authorities indicate switches to the engines’ fuel supplies were moved from the “RUN” position to “CUTOFF”.

It revealed the exchange between both pilots, but did not identify which comments were made by the flight’s captain and which were made by the first officer.

It said that it does not “identify the cause – whether it was crew error, mechanical malfunction, or electronic failure.”

Flipping the switches to cut off almost immediately cuts the fuel supply to the engines.

It is most often used to turn engines off once a plane has arrived at its airport gate and in certain emergency situations, such as an engine fire.

But the inconclusive report, which came after 30 days of the crash, does not indicate that the flight encountered any such emergency situation.

It is almost impossible to turn the switches off accidentally – they must be pulled up and locked before flipping – a safety design feature that was introduced decades ago.

Protective guards are further installed to minimise the risks – raising further questions as to why the fuel switches in the Air India flight were turned off.

Key findings of the initial crash report:

• Dual engine shutdown – fuel cutoff switches moved from ‘RUN’ to ‘CUTOFF’
• Confusion between pilots – cockpit audio confirms one pilot asked ‘why did you cutoff’, the other replied ‘I didn’t’
• RAT deployed – as seen in CCTV footage before the crash
• Engine relight attempted – fuel switches were found returned to the “RUN” at crash site
• 32 seconds – the time the aircraft was airborne before it crashed
• Thrust levers mismatch – Thrust levers found at idle but black box data shows takeoff thrust was still engaged
• Fuel test pass – fuel was clean without any contamination
• Normal take-off set-up – Flaps and landing gear correctly configured
• No bird activity – clear skies, good visibility, light winds
• Pilot credentials clear – both medically fit and rested
• No sabotage detected – although FAA alerted over a known fuel switch vulnerability not checked by Air India
• Aircraft loading – the flight was within weight and balance limits

It is worth noting that the initial crash report points out that the US Federal Aviation Administration (FAA) in 2018 issued a Special Airworthiness Information Bulletin (SAIB) – highlighting that a few Boeing 737 fuel control switches were installed with the locking feature disengaged.

But it was not deemed unsafe, and no Airworthiness Directive (AD) – a legally enforceable regulation to correct unsafe conditions in a product – was issued.

A similar switch design is used in Boeing 787-8 aircraft, including Air India’s VT-ANB Dreamliner in question.

The FAA and Boeing have now privately issued notifications that the fuel switch locks on Boeing planes are safe, according to four sources and a document seen by Reuters.

The report said Air India had said it had not carried out the FAA’s suggested inspections, as the FAA 2018 advisory was not a legal mandate.

But it also said maintenance records showed that the throttle control module, which includes the fuel switches, was replaced in 2019 and 2023 on the plane involved in the crash.

The Boeing 787 Dreamliner with 242 passengers on board – including 53 Brits – smashed into a doctors’ hostel in Ahmedabad in the west of India.

The plane was headed to London Gatwick when it crashed just seconds after take-off, killing all but one passenger.