Mumbai: Foundation for Aviation Safety (FAS), a US aviation safety group, has written to India’s Aircraft Accident Investigation Bureau (AAIB) questioning why it has not issued interim safety recommendations for the Boeing 787 fleet, despite holding evidence of chronic system failures on the aircraft involved in last year’s Ahmedabad crash, which killed 260 people.
“What I do know is that VT-ANB had plenty of EWIS failures,” Pierson said, citing the non-public documents. EWIS has been identified as a causal factor in many accidents,” Pierson said. “It also had primary power distribution failures, not just EWIS, but actual power generation, stable, high-quality electrical power. It had lots of problems with that. It had all those other issues: open circuits, short circuits, burning, arcing, fire, etc. He explained that problems could arise from wiring routed too close together, chafing against sharp edges, or improper bonding and grounding, leading to electricity going places it’s not supposed to go. “You can have a lot of issues with EWIS.
The 787’s EWIS spans over 150 km of wiring, more than 3,500 connectors and 40,000 cable segments.
Pierson told TOI the crashed aircraft’s records showed recurring failures in its Electrical Wiring Interconnection System (EWIS). FAS first outlined the documents’ contents in a Jan presentation to US Senate Permanent Subcommittee on Investigations. It’s the network of all wires, cables and connectors distributing electricity, data and signals through the aircraft.
Over the past year, FAS said it had received more than 100 non-public documents specific to the crashed Air India 171 aircraft (VT-ANB). These documents explicitly detail chronic, systemic aircraft failures involving the airplane’s electrical, electronic, and/or flight computer systems,” said Ed Pierson, FAS executive director, in an email to AAIB director general on Aug 29. FAS sent these documents to AAIB via the UK AAIB expert. “The documents are vital to reconstructing the operational history of the doomed airplane. “By actively withholding this information from public announcements, the AAIB is failing its primary objective, the prevention of future accidents through timely, transparent safety disclosures. Most critically, despite being in possession of evidence pointing to chronic and dangerous system failures, the AAIB has issued zero interim safety recommendations or warnings to the global aviation community,” it added.