The government informed Parliament that no defects were found in the fuel control switch locking mechanism of an Air India Boeing 787-8 aircraft that was grounded in February after the pilot of a London-Bengaluru flight (AI 132) reported a possible issue with the switch. Fuel control switches on the same aircraft model are also under scrutiny in the investigation into last year's Ahmedabad plane crash, which claimed 260 lives.
Fuel control switches regulate the supply of fuel to an aircraft's engines. In its reply, the government said the aircraft's complete thrust control module is currently undergoing inspection at a Boeing facility.
It added that a detailed examination of the fuel control switch, including the structural integrity of its locking detents, found no abnormalities. The testing was conducted at Boeing's Seattle facility in the presence of a Directorate General of Civil Aviation (DGCA) officer because of the sensitive nature of the examination.
The aircraft had departed London on February 1 and landed safely in Bengaluru. After landing, the pilot reported a suspected issue with the left engine's fuel control switch.
According to the report, the switch failed to lock into the "run" position on two attempts and slipped toward the "cutoff" position when slight pressure was applied. However, the issue did not recur on the third attempt, allowing the crew to complete the flight safely.
If a fuel control switch moves to the "cutoff" position, it stops the fuel supply to the engine, leading to an engine shutdown.
The February incident brought renewed attention to fuel control switches on Boeing 787-8 aircraft. Air India operates the Boeing 787 Dreamliner on several international routes, including flights to the United Kingdom.
Ahmedabad crash investigation
On June 12, another Boeing 787 operating as Air India flight AI 171 crashed in Ahmedabad just seconds after take-off while operating the Ahmedabad-London route, killing 260 people. The aircraft lost power shortly after becoming airborne and crashed into a medical college hostel near the airport.
The Aircraft Accident Investigation Bureau's (AAIB) preliminary report revealed that both fuel control switches moved from the "run" to the "cutoff" position almost simultaneously after take-off, cutting fuel supply to both engines and leading to the crash.
However, the report did not determine why the switches moved, leaving open the possibility of either a mechanical malfunction or another cause. It also noted that one pilot asked the other why he had "cut off" the fuel supply, to which the other pilot replied that he had not.
Following the accident, Air India said inspections of the fuel control switch locking mechanisms across its Boeing 787 fleet had not identified any defects.
The final investigation report into the Ahmedabad crash is expected before the end of October.
Responding to questions in Parliament, the government defended the time taken to complete the investigation, saying complex air accident probes cannot be completed within a fixed deadline.
"The timeline for a major accident investigation cannot be predicted, as it depends on several factors and is an evolving process involving multiple variables," the government said.
