NEW DELHI: Air India is under regulatory scanner for deploying a “wrong” Boeing 777 with less than the required amount of emergency-use oxygen to operate a Delhi-US nonstop recently. The pilot refused to operate this aircraft on this route after detecting the same and now the Directorate General of Civil Aviation (DGCA) has sought information from the airline on this serious oversight.The pilot has since left the airline.
Most aircraft have cylinders to supply oxygen to overhead masks that deploy in case of cabin de-pressurisation for 12-15 minutes per passenger. This time is enough for planes for descend to 10,000 feet after which they are in an ambient environment safe for humans. At that altitude air is fed from the engine for cooling the aircraft and breathing.
However, aircraft overflying high mountains can descend to 10,000 feet only after clearing the range. Which means they need to fly for much longer at higher altitude, and that requires extra cylinders on aircraft to supply oxygen to overhead passenger masks for 25-30 minutes.
AI nonstops between Delhi and Europe and most North American cities overfly the mighty Hindu Kush range to bypass Afghan airspace ever since the same was closed for civilian traffic over two years back. The airline’s old Boeing 777s have an extra oxygen cylinder and regularly take this route. Recently AI took more B777s that do not have the extra cylinder and are okay to fly between west and south India and North America as those flights do not overfly the Hindu Kush.
“AI’s nonstops between Delhi and North America are almost entirely (barring one or two exceptions) on old B777s that have extra oxygen cylinder. That day somehow an ex Delta new Boeing 777, which does not have extra cylinder, was deployed to operate a nonstop from Delhi to the US. The pilot detected the lapse, pointed out the same to AI and refused to operate the flight,” say sources.
An AI spokesperson said: “The matter in question is multi-dimensional and has already been examined by Air India and external experts. We will restrain from offering any comment on this specific case but we wish to reiterate that the safety of our passengers and crew is our foremost priority and there is no compromise on the same.”
The airline also perhaps realised its error and then this aircraft took a longer route to the US which did not require overflying the Hindu Kush, say sources. “The peaks in Hindu Kush ranges are 19,000-26,000 feet high. In case of cabin de-pressurisation while overflying them, aircraft need to fly for 22-30 minutes before they can descend to 10,000 feet and head to a safe alternate airport like Tashkent. This protocol was devised by AI about two years back when the Afghan airspace was closed for civilian overflying. Deploying an aircraft to overfly the Hindu Kush that does not have the mandatory extra oxygen supply is a serious oversight,” said people in the know.
Aircraft flying to Leh also have extra oxygen cylinder.
For the high terrain Hindukush route, AI had in 2021 carried out preparations through extra simulator drills, trial runs and special precautions to be taken. “This is the first time we will be taking the Hindu Kush route (technically called P500 and G500). The Afghan airspace closure would have been a cost escalation nightmare due to rising fuel prices. When we sat down together how to beat this latest emerging crisis, the Hindu Kush presented itself as the answer,” a senior AI official had told this reporter at that time.

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