Boeing has begun certification testing of the braking system used in the in-development 777-9 long-haul aircraft. "In this phase of certification testing, our team will demonstrate the safety and reliability of the 777-9's aerodynamics, brakes and engines, ensuring compliance to rigorous regulatory requirements," says Stephanie Pope, chief operating officer of Boeing and president and chief executive of its commercial airplanes division, in a LinkedIn post. She adds that "this month's tests are being conducted with US Federal Aviation Administration personnel on board after our regulator expanded type inspection authorisation for the 777-9, confirming the airplane’s readiness". Boeing chief executive Kelly Ortberg said on 20 February during the Barclays Industrial Select Conference that the US manufacturer hopes to achieve certification for the in-development 737 Max 7 and 10 variants later this year, and is targeting early 2026 for certification of 777-9. He noted at the time that the 777-9 is undergoing a flight-test programme.

British Airways chief executive Sean Doyle has warned that the "unprecedented" closure of Heathrow airport because of a fire and power failure will result in multi-day disruption for the airline. In a video message to customers, Doyle warned that the airline still does not know when the airport will reopen, "but even when that does happen, this incident will have a substantial impact on our airline and customers for many days to come, with disruption to journeys expected over the coming days." Heathrow initially said it hoped to reopen the airport by midnight, although whether this will happen is unclear. BA has already "effectively" grounded it’s flying operation, "cancelling every short-haul and the majority of long-haul flights that were scheduled to operate throughout today," says Doyle. In total, BA says it was due to operate more than 670 flights from Heathrow carrying around 107,000 customers, with similar numbers planned for the weekend. Customers are being asked not to travel to the Heathrow, with many services that were inbound are being diverted to other UK points or even further afield. It notes that crews and aircraft are out of place because flights were diverted to alternative airports. The extra element of crews who can only work for a certain number of hours over any given period of time "adds further complexity" to the recovery operations, adds Doyle. "In addition, our engineering and maintenance operation have also had no power," he says. “This is being addressed but is another example of the incredibly challenging situation we find ourselves in.”

Seconds before an MHIRJ CRJ900 operated by Endeavor Air on 17 February landed at Toronto Pearson, lost a wing and came to rest inverted, an alert indicated a high rate of descent, the Transportation Safety Board of Canada (TSB) says in a preliminary report on the incident issued on 20 March. The CRJ900 operated by wholly owned Delta subsidiary Endeavor as Delta flight 4819 had departed Minneapolis/St Paul International. During the landing on runway 23 at Toronto Pearson, the aircraft's right wing detached, and a fire ensued, the TSB says in its preliminary report. The aircraft carrying 76 passengers and four crew members overturned and slid down the runway inverted, coming to rest near the intersection of runway 23 and runway 15L, it adds. Passengers were hanging upside down in their seats, suspended by their safety belts. "Some passengers had difficulty releasing the buckles on their safety belts due to being inverted," the TSB says in its report. "Some of the injuries sustained by the passengers occurred when they unbuckled their safety belts and fell to the ceiling." It adds: "At the time of writing this preliminary report, it has been confirmed that 21 of the 80 occupants were injured; two of those occupants were reported to have serious injuries." At 3.6 seconds before touchdown, when the aircraft was at a height of 50ft above ground level (AGL), the enhanced ground proximity warning system (EGPWS) aural alert "fifty" sounded to indicate the aircraft was at 50ft AGL, which is a standard callout, TSB reports. "One second later (2.6 seconds before touchdown), the EGPWS alert 'sink rate' sounded, indicating a high rate of descent." It adds: "At touchdown, the following occurred: the side-stay that is attached to the right MLG [main landing gear] fractured, the landing gear folded into the retracted position, the wing root fractured between the fuselage and the landing gear, and the wing detached from the fuselage, releasing a cloud of jet fuel, which caught fire. The exact sequence of these events is still to be determined by further examination of the fracture surfaces." Delta stated on 20 March that "for everyone at Endeavor Air and Delta, nothing is more important than the safety of our customers and our people". The US major adds: "That's why we remain fully engaged as participants in the investigation led by the Transportation Safety Board of Canada. Out of respect for the integrity of this work that will continue through their final report, Endeavor Air and Delta will refrain from comment." Delta chief executive Ed Bastian said on 11 March at the JP Morgan Industrials Conference that the 17 February incident "fed into another round of delay" in the recovery of bookings and consumer sentiment following the fatal 29 January collision of a US Army Sikorsky H-60 Black Hawk helicopter and a PSA Airlines MHIRJ CRJ700 regional jet (operating flight 5342 for American Airlines) on final approach to Ronald Reagan Washington National airport's runway 33.