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Business Standard
2 days ago
- General
- Business Standard
Air India plane crash: Understanding the role of fuel control switches
The Air India AI171 crash highlights the critical role of fuel control switches, which caused a dual-engine failure just after takeoff, leading to the tragic loss of 260 lives Deepak Patel New Delhi What Are Fuel Control Switches? Fuel control switches on the Boeing 787 are critical cockpit levers that control whether fuel flows to the aircraft's engines. Each engine has its own switch, located at the base of the throttle levers on the central control pedestal. These switches can be set to two positions: RUN, which allows fuel to flow to the engine, and CUTOFF, which stops fuel supply and shuts down the engine. To prevent accidental activation, the switches are spring-loaded and require a two-step action: the pilot must pull the switch outward and then rotate it. This deliberate motion ensures that the switches cannot be bumped or moved unintentionally. Pilots typically operate the fuel control switches during two key phases: at engine start-up on the ground and during engine shutdown after landing. Outside of these routine phases, the switches are used only in very specific in-flight emergency situations—such as an engine fire, severe engine damage, or other serious malfunctions—when the crew needs to quickly cut off fuel to prevent further hazard. According to the preliminary crash report made public by the Aircraft Accident Investigation Bureau (AAIB) on Saturday, both fuel control switches on Air India flight AI171 moved from the RUN to the CUTOFF position three seconds after the aircraft became airborne from Ahmedabad on 12 June. This simultaneous transition led to the immediate loss of thrust in both engines. With no engine power and little altitude, the aircraft was unable to maintain lift and crashed within seconds into the BJ Medical College hostel compound, resulting in 260 fatalities. The report does not clarify whether the switches were physically moved by a pilot or changed state due to a mechanical or electrical issue. Regardless of the cause, the result was an uncommanded and complete engine failure at the most critical phase of flight—right after takeoff—when altitude and time were limited. What Pilots Are Trained to Do — and Why Time Ran Out In the event of an engine shutdown, pilots are trained to refer to the Quick Reference Handbook (QRH), a manual kept in the cockpit that outlines step-by-step procedures for handling emergencies. For dual engine failure, the QRH instructs the crew to stabilise the aircraft's glide path, confirm the failure, and attempt an engine restart. This includes checking switch positions, verifying fuel flow, and initiating relight procedures using both airspeed and electrical power. On the Boeing 787, the relight process also depends on minimum altitude and airspeed thresholds being met. In the case of AI171, the dual-engine power loss occurred just after takeoff—at extremely low altitude and within seconds of becoming airborne. According to the preliminary report, the pilots did attempt to restart the engines and were able to relight the left engine. However, by that time, the aircraft had already lost critical speed and altitude, leaving little margin for recovery. The plane did not gain enough thrust to climb or stabilise, and crashed into the BJ Medical College hostel compound seconds later. Although the crew followed emergency protocols under extreme time pressure, the conditions left no meaningful window to complete the full QRH checklist or regain control of the flight.
India Gazette
2 days ago
- Business
- India Gazette
"Not about witch hunt to blame pilots but ...": Aviation Safety consultant Mark D Martin slams AAIB report on Air India flight 171 crash
New Delhi [India], July 13 (ANI): Aviation safety consultant and founder and CEO of Martin Consulting, Mark D Martin, on Sunday called for a fair and 'unbiased' investigation into the recent Air India flight 171 crash, emphasising that the preliminary investigation report released by the Aircraft Accident Investigation Bureau (AAIB) tried to 'put the blame deliberately on the pilots and exonerate the OEM (Original Equipment Manufacturer).' During an interview with ANI, Martin criticised the report for its focus on pilot actions, particularly the movement of engine fuel cutoff switches from 'run' to 'cutoff' within seconds, despite initial indications of engine failure. 'World pilots are not stupid. World pilots know the truth. And a pilot who puts his life on the line for his family's livelihood will not fall for this report, even if they are aware.... It's time we take this investigation seriously. This is not about a witch hunt to blame the pilots. It's about a fair and just investigation,' he said. 'My point is very simple. When you don't have the engines in the first place, when the engines have failed, when fuel is not going to the engine, why does the point of fuel cut-off come up? Now what they're trying to do is put the blame deliberately on the pilots and exonerate the OEM (Original Equipment Manufacturer), and that is not correct,' he argued while questioning the logic behind the report's narrative. He highlighted the procedural context, noting that fuel cutoff procedures are relevant only when engines are operational, not when they have already failed. 'Fuel cutoff logic comes only when the memory item and procedure and QRH (Quick Reference Handbook) for starting the engine are that you have to put the switch back in to cut off and bring it back on. Now that is something which has happened, but that has happened to engines that were already when the engines had already failed, so it doesn't make sense,' he explained. The consultant also raised concerns about the timing and audience of the report's release while suggesting a bias in the investigation process. 'Second, which is very shocking, is why did the report come out at 2 am in the morning when the aircraft is Indian... It is close of business for the UK. But you're releasing it at 2 a.m. for the American audience. That does not make sense at all,' Martin said. He pointed out the global impact of the crash, which claimed 260 lives, describing it as 'probably the worst air disaster in 40 years' and urging Prime Minister Narendra Modi to intervene. 'I'm repeating myself; I'm urging honourable Prime Minister Shri Modi ji to please intervene. We cannot have a biased investigation report because 787s, these aircraft, are flying across the world and even as we speak, there is a rippling effect with operators across the world,' he stated. Martin also condemned baseless conspiracy theories, particularly remarks suggesting pilot suicide, calling them 'the most ridiculously stupid thing a pilot can say about another pilot without having any evidence, any information, or any logic', calling for the need for proactive communication from the government to counter such narratives. On Friday, India's AAIB released the preliminary report into the tragic crash of Air India flight 171, a Boeing 787-8 aircraft, which crashed shortly after takeoff from Ahmedabad's Sardar Vallabhbhai Patel International Airport on June 12. The report has sparked a controversy in the aviation industry and the general public for allegedly blaming the crash on pilots. (ANI)
Yahoo
30-05-2025
- Business
- Yahoo
NTSB cites hydraulic and electrical failures in FedEx 757 gear failure
The National Transportation Safety Board has determined that a FedEx Boeing 757-200's belly landing in Chattanooga, Tennessee, was caused by the failure of the alternate gear extension system, which prevented the landing gear from being lowered during an emergency. On Oct. 4, 2023, FedEx (NYSE: FDX) flight 1376 experienced an 'abnormal runway contact' when the flight crew was unable to extend the landing gear during the approach to Chattanooga's Lovell Field. Shortly after takeoff from Chattanooga, the captain called for gear up, and the first officer raised the landing gear control lever to retract the landing gear. Both the main landing gear and nose landing gear retracted to their up and locked position. Digital flight data recorder data showed that 22 seconds after gear retraction, the hydraulic fluid quantity and pressure in the left hydraulic system began to decrease. After troubleshooting the hydraulic issue per procedures in the Quick Reference Handbook, the flight crew made the decision to return to Chattanooga. While preparing to land, the landing gear did not extend as expected when the landing gear control lever was positioned to its down position.'Gear disagree. The gear is not coming down,' the first officer confirmed, according to cockpit voice recorder data documented by the NTSB. Despite multiple attempts to deploy the landing gear using both normal and alternate extension systems, the crew was forced to perform a belly landing. The aircraft slid off the departure end of Runway 20 and impacted localizer antennas before coming to rest about 830 feet beyond the end of the runway. Postaccident inspections of the landing gear system found that hydraulic fluid was leaking from the left landing gear door actuator retract hydraulic hose. Inspections also found that the engine indication and crew alerting system showed the left hydraulic system had only 32% fluid quantity remaining after the main landing gear door retraction shortly after takeoff, which is considered fully depleted. Analysis of the failed hydraulic hose revealed multiple broken wire strands along its length and a rupture in its inner liner. The cause of the broken wire strands most likely originated from an overload event as evidenced by the necking down of the wire strands and a reduction in their area, investigators critically, electrical system inspections of the alternate extension system found no electrical continuity between the alternate gear extend switch and the alternate extension power pack. A visual examination revealed a break in a wire between the circuit breaker and the alternate gear extend switch, which prevented the system from functioning as a backup. 'Analysis of the wire's fracture surfaces showed a reduction in area and circumferential cracking of the coating, consistent with tensile loading,' the final report stated. 'No obvious defects or anomalies were observed on the fracture surfaces.' The investigation also identified issues with the aircraft's evacuation equipment. After the airplane came to a stop, the jumpseat occupant attempted to open the L1 door, which only rotated halfway open and would not fully deploy. The R1 door also became lodged on the slide pack before the jumpseat occupant used force to open it. Investigators found that the R1 door's bannis latch did not conform to the configuration required by an FAA Airworthiness Directive from 1986, which caused the slide pack to jam during evacuation. The NTSB determined the probable cause of this accident to be 'the failure of the alternate gear extension system, which prevented the landing gear from being lowered. The cause of the system failure was a broken wire, due to tensile overload, between the alternate gear extend switch and the alternate extension power pack, preventing the AEPP from energizing and supplying hydraulic fluid to the door lock release actuators for the nose landing gear and main landing gear.' Contributing to the accident was 'the loss of the left hydraulic system due to a ruptured left main gear door actuator hose from fatigue, which prevented normal landing gear operation.' The NTSB noted that the crew of FedEx flight 1376 demonstrated good Crew Resource Management during the emergency, remaining calm and professional throughout the accident sequence. They displayed effective workload management by distributing tasks among themselves, with the captain flying and the first officer working to resolve the issue with air traffic control. 'The crew maintained clear and concise communication between all crewmembers to include a jumpseat occupant, and with ATC, actively soliciting feedback and input, and crosschecking with one another to ensure everyone was working with the same mental model,' the report a result of this investigation, the NTSB issued four new safety recommendations to the FAA and three new recommendations to Boeing on March 27, 2025. These recommendations address the need to inspect and modify bannis latches on Boeing aircraft doors and update aircraft maintenance manuals with correct configurations. Following the accident, FedEx implemented a 275 Flight Hour check on the alternate extension system, including performing a general visual inspection while the nose landing gear and main landing gear doors are open while on the ground. Related: FedEx 757 accident prompts NTSB call for door latch inspections (This article is republished from Airline Geeks.) The post NTSB cites hydraulic and electrical failures in FedEx 757 gear failure appeared first on FreightWaves.
