By Shafali Nigam

New Delhi [India], July 14 (ANI): India's civil aviation regulator, Directorate General of Civil Aviation (DGCA) on Monday issued an urgent directive mandating Indian operators of specific Boeing aircraft models to conduct inspections of the engine fuel control switch locking mechanisms by July 21.

The move comes days after report of preliminary investigation into the crash of Air India flight AI 171 in Ahmedabad in which killed 260 people.

The directive enforces compliance with the Federal Aviation Administration's (FAA)'s Special Airworthiness Information Bulletin (SAIB) NM-18-33, issued in December 2018, which warned of the potential disengagement of the fuel control switch locking feature in operators of Model 737 airplanes Boeing aircraft, as mentioned in AI 171 preliminary report.

The fuel control switch design, including the locking feature, is similar on various Boeing airplane models including part number 4TL837-3D which is fitted in B787-8 aircraft VT-ANB, the preliminary report added.

The fuel control switch design--including the locking feature--is shared across several Boeing aircraft families, including the 737, 747, 757, 767, 777, and 787, the report said.

AAIB's findings reignited concern over why many airlines had delayed or skipped the inspections, even after the issue had been flagged internationally.

The order mandates all affected operators to complete inspections in line with the FAA's SAIB NM-18-33 and submit their inspection plans and final compliance reports to both the DGCA and relevant regional offices.

The DGCA noted in its directive that several international and domestic operators had voluntarily begun compliance following the FAA bulletin.

The order explicitly refers to India's Civil Aviation Requirement (CAR) M-M.A. 301, which obligates operators to comply with safety directives from aircraft manufacturers or regulators of the aircraft's state of design, in this case, the U.S. FAA.

'Strict adherence is essential for continued airworthiness and safety of operations,' the DGCA stated.

India's Aircraft Accident Investigation Bureau (AAIB) released the preliminary report into the tragic crash of Air India flight AI171, a Boeing 787-8 aircraft, which crashed shortly after takeoff from Ahmedabad's Sardar Vallabhbhai Patel International Airport on June 12.

The crash killed 260 people, including 229 passengers, 12 crew members, and 19 people on the ground.

Flight data recovered from the aircraft's Enhanced Airborne Flight Recorder (EAFR) revealed that the fuel cutoff switches for both engines were inadvertently moved from RUN to CUTOFF, one after another within a 1-second interval, at an altitude just moments after liftoff. One pilot was heard asking the other, 'Why did you cut off?' to which the response was, 'I did not.'

This uncommanded shutdown triggered the deployment of the Ram Air Turbine (RAT), and the aircraft began losing altitude almost immediately, unable to sustain powered flight.

According to the AAIB, the pilots re-engaged the fuel switches in an attempt to relight both engines. Engine 1 showed signs of recovering thrust, but Engine 2 failed to stabilise.

The aircraft, which had briefly reached a speed of 180 knots, was already descending and failed to regain altitude. The final distress call -- a 'MAYDAY' -- was transmitted at 08:09 UTC, just seconds before the aircraft crashed into residential buildings outside the airport perimeter. (ANI)