Closer video analysis apparently reveals that the RAT had deployed during the initial climb of the Air India 787. Despite not having sat on a flight deck for seven years I was pleased to be able to recall that this occurs not only due double engine failure but due major electrical and hydraulic problems... although of course the first cause would lead to the second and third, which is what triggers deployment.
The BANG heard by the one survivor could it seems relate to an interruption to the flow of air through either engine, although again you could not rule out starvation of fuel to some extent leading to a mismanagement of that delicately-balanced airflow with that same result.
In the unlikely event of contamination the focus then shifts then to some extent to vaporisation of the fuel, and again history informs us... the most recent dual failure being attributable to ice clogging the fuel filters during the descent and approach of a British Airways Boeing 777 into Heathrow airport.
Jet fuel has an upper and lower operating limit, the former being circa 49C. Given the temperature was at least 43C at the airport on the day, superheated fuel that is more prone to 'boil' cannot therefore be discounted.
There was during my time flying a hullabaloo after the explosion in mid-flight of an airliner departing the US that was attributed to an electrical spark igniting the fuel vapour in a TWA 747.
Beside this there have been two instances of 737s exploding on the ground due an overheating of fuel in the tanks.
Key to all three incidents was high ambient temperature during a prolonged spell on the tarmac: which was undoubtedly the case in India. A feature of hot weather is that the air conditioning systems are working flat out during stop overs to keep you comfortable, though an undesirable by-product of that is the fact air-con units live close by the fuel-tanks.
Combine all of these sources of heat viz. solar radiation absorption, hot-air exhaust, thermal heating of apron and runway, collective body-heat and on and on... and the safe operating limit of 49C does not seem all that remote any more.
Like AI and its role in flight management, however, this could ultimately be a very modern problem: due human-induced climate change, hotter parts of the world are getting hotter.
