MUMBAI: The Delhi HC has issued a notice to the Centrein a writ petition filed by a pilot seeking flight data recorder information of the Air India Express aircraft that hit the Trichy airport’s perimeter wall during takeoff in 2018. This is probably the first time in India that a HC has been approached with a plea to release flight data pertaining to an accident.The Central government standing counsel has sought time to file a reply.
The petitioner’s contention is that the Aircraft Accident Investigation Bureau (AAIB) skipped or ignored a crucial angle in its final report released in 2021. “Was the AIX Boeing 737 aircraft actually heavier than the weight recorded in the document given to the pilots by the ground crew?” said Capt Amit Singh, the petitioner. Singh, an airline pilot with over 17,000 hours’ experience, is the founder of the NGO Safety Matters Foundation. He is also a fellow of the Royal Aeronautical Society, UK. On October 11, the AIX plane sped into the unpaved area. It suffered a tail strike, hit a piece of equipment and the top of the perimeter wall before it could climb out.
The impact lacerated a portion of its underbelly, but did not hit flight operations. The pilots continued the flight till the aircraft was over the Arabian Sea, when the airline instructed the pilots to divert to Mumbai, where it landed safely.
The AAIB report said the probable cause of the accident was “delayed take-off due to reduction of takeoff thrust from 98% to 77% before reaching the decision speed-the speed beyond which take-off should be continued. The AAIB report cited “inability of both the crew members to monitor the thrust parameters and to take timely corrective action”. “But even if only one of the two engines were working (50% thrust only), the Boeing 737 is certified to clear all obstacles under the take-off path and climb out safely,” said Capt Singh.
The petition drew comparison with similar occurrences of reduced thrust involving Boeing 737 aircraft. For instance: at Kuusamo airport, Finland, on December 1, 2021, the thrust setting of a Boeing 737 was at 70% from initiation of take-off roll and yet about 1,300 feet before the runway end, the aircraft lifted off ground, the petition said, adding that there have been many such instances, but none led to an accident.
The weight of an aircraft after passengers, crew, bags, cargo and fuel are loaded is an important measure based on which pilots calculate various speeds, including the speed (Vr) at which the aircraft would get airborne during the take-off roll. Heavier the aircraft, higher is the Vr speed. “The AIX aircraft could not lift off at Vr speed. When landing into Mumbai, the aircraft’s approach speed was higher than usual, again indicating it was heavier than stated in the document,” said Capt Singh.
The flight data recorder (FDR) is one of the two black boxes and it records parameters of flight operation such as aircraft speed, altitude, flight path, and engine power. Using the FDR data, the real weight of the AIX Boeing 737 during take-off from Trichy could be computed, he said. “The public has the right to the FDR information,” said Capt Singh, adding, countries such as the US, for instance, release FDR data to the public. The petitioner moved court after an RTI application filed in May 2022, followed by appeals seeking that release of the said FDR data were rejected by the chief information commissioner citing section 8(1)h of the RTI Act. It states: “There shall be no obligation to give any citizen information which would impede the process of investigation or apprehension or prosecution of offenders.” But the investigation is over.
The petitioner’s contention is that the Aircraft Accident Investigation Bureau (AAIB) skipped or ignored a crucial angle in its final report released in 2021. “Was the AIX Boeing 737 aircraft actually heavier than the weight recorded in the document given to the pilots by the ground crew?” said Capt Amit Singh, the petitioner. Singh, an airline pilot with over 17,000 hours’ experience, is the founder of the NGO Safety Matters Foundation. He is also a fellow of the Royal Aeronautical Society, UK. On October 11, the AIX plane sped into the unpaved area. It suffered a tail strike, hit a piece of equipment and the top of the perimeter wall before it could climb out.
The impact lacerated a portion of its underbelly, but did not hit flight operations. The pilots continued the flight till the aircraft was over the Arabian Sea, when the airline instructed the pilots to divert to Mumbai, where it landed safely.
The AAIB report said the probable cause of the accident was “delayed take-off due to reduction of takeoff thrust from 98% to 77% before reaching the decision speed-the speed beyond which take-off should be continued. The AAIB report cited “inability of both the crew members to monitor the thrust parameters and to take timely corrective action”. “But even if only one of the two engines were working (50% thrust only), the Boeing 737 is certified to clear all obstacles under the take-off path and climb out safely,” said Capt Singh.
The petition drew comparison with similar occurrences of reduced thrust involving Boeing 737 aircraft. For instance: at Kuusamo airport, Finland, on December 1, 2021, the thrust setting of a Boeing 737 was at 70% from initiation of take-off roll and yet about 1,300 feet before the runway end, the aircraft lifted off ground, the petition said, adding that there have been many such instances, but none led to an accident.
The weight of an aircraft after passengers, crew, bags, cargo and fuel are loaded is an important measure based on which pilots calculate various speeds, including the speed (Vr) at which the aircraft would get airborne during the take-off roll. Heavier the aircraft, higher is the Vr speed. “The AIX aircraft could not lift off at Vr speed. When landing into Mumbai, the aircraft’s approach speed was higher than usual, again indicating it was heavier than stated in the document,” said Capt Singh.
The flight data recorder (FDR) is one of the two black boxes and it records parameters of flight operation such as aircraft speed, altitude, flight path, and engine power. Using the FDR data, the real weight of the AIX Boeing 737 during take-off from Trichy could be computed, he said. “The public has the right to the FDR information,” said Capt Singh, adding, countries such as the US, for instance, release FDR data to the public. The petitioner moved court after an RTI application filed in May 2022, followed by appeals seeking that release of the said FDR data were rejected by the chief information commissioner citing section 8(1)h of the RTI Act. It states: “There shall be no obligation to give any citizen information which would impede the process of investigation or apprehension or prosecution of offenders.” But the investigation is over.