A small cockpit component is now at the centre of one of aviation‘s most scrutinised safety investigations. India has sent a fuel control switch from a Boeing 787 Dreamliner to the United States for a more thorough examination, which escalates the already sensitive investigation of a system that directly controls engine power while the aircraft is being flown. The act itself indicates caution and urgency as both regulators from two different continents strive to clear up the uncertainty regarding the dependability of a mechanism that rarely sees any hands-on use during normal operations, yet has an immediate and life-critical command of jet propulsion.
The component being examined is a part of the throttle control system on the aeroplane – specifically, the fuel control switches are what activate and deactivate fuel to the engines. Pilots will typically only use the fuel control switches during a ground start or shutdown of the engines on the ground; when the aeroplane is flying, there is no use of the switches unless there is an emergency. As a result, a false move could have an immediate and disastrous effect, as the aeroplane’s engines would have an immediate decrease in engine thrust due to having the fuel supply stopped.
In addition to the original portion of the investigation drawing more global interest, it is part of an ongoing larger investigation into safety issues related to Boeing 787 aircraft. The inspection of the Air India incident has raised significant safety concerns regarding control switches and whether the locking mechanism functions appropriately as designed. Although no definitive conclusions have been made regarding the switches, aviation safety authorities have decided to perform a more extensive technical review than would normally occur.
As part of the investigation, regulatory sources say that Indian aviation authorities are collaborating with U.S. aviation safety officials and Boeing engineers to check the switch assembly to see if it accidentally moves out of place or doesn’t stay in the “RUN” position because of certain operating or mechanical issues. The testing will occur in controlled environments in Seattle.
The engineering safeguard on which the investigation relies is the metal stop-lock system that prevents the switch from inadvertently moving. Pilots must physically lift the switch to turn it on, intentionally preventing random activation. However, before this investigation, global aviation safety authorities had already warned about a small risk of problems due to wear, misalignment, or failure of safety features on similar parts.
The most recent action continues a trend towards closer oversight of systems related to Boeing’s 787 aircraft, which has been an area of increasing concern since the number of safety incidents connected to the type has increased. While the FAA (the U.S. Federal Aviation Administration) and aircraft manufacturers have consistently stated that the Dreamliner remains a safe aircraft to operate, airlines across the globe are voluntarily inspecting all critical aircraft systems as a result of the individual incidents that have occurred.
Industry experts say that utilising an external organisation to physically inspect a part is a major component of aviation investigations. External organisations can provide independent verification of mechanical integrity, material behaviour when subjected to stress and/or any defects that can’t necessarily be seen with a regular inspection.
For Air India and the regulators in January, the decision to return to long-haul operations of the Dreamliner reflects a very cautious and prudent decision to rebuild trust in the long-haul operations of this aircraft type. For Boeing, it represents one more step in an extended commitment to maintain the confidence of the aviation community in one of its most successful long-range aircraft.
Although an immediate safety directive has not been released, the results of the ongoing work may change future inspection procedures for fuel control systems and set standards for them around the globe if any irregularities are found.
