GE Aerospace anticipates that open-fan architectures will deliver engine durability improvements in addition to fuel savings versus conventional, ducted turbofans. The US manufacturer's chief executive, Larry Culp, said at the Bernstein Strategic Decisions Conference on 27 May that the propulsive efficiency gains presented by the high bypass ratios of unducted fans open up opportunities for more durable gas turbines "because you are putting less stress on the core, the hot section of the engine [where] all the wear and tear takes place over time". "We think there's a significant durability and reliability benefit to be had," he adds. GE is exploring, with Safran, the feasibility and potential benefits of open fans through the RISE future-technology programme of their jointly owned CFM International subsidiary. Under RISE – short for revolutionary innovation for sustainable engines – GE and Safran are additionally studying technology for the core of a next-generation single-aisle engine, hybrid-electric power and the use of sustainable aviation fuel and hydrogen. Overall, GE and Safran aim to reduce fuel burn by at least 20% compared to CFM's current Leap engine series. Culp observes that airlines have become more concerned about engine durability as fuel-efficient new-generation engines have required more maintenance than previous-technology equipment. "It wasn't that long ago when almost anyone who came to talk to us focused on sustainability," he says, adding: "Today, for understandable reasons, customers have evolved to a much greater focus on reliability [and] durability, making sure that when they need the engines to go, that they're good to go." An open fan will deliver both fuel and maintenance savings, Culp argues. "You don't have to trade one for the other." If Airbus or Boeing were to adopt the open fan for a next-generation single-aisle, the engine would affect the overall aircraft design more than is the case with today's turbofans, and therefore require closer co-operation between airframe and engine manufacturers. "We are going to be much more collaborative as we think about the integration of an open-fan architecture and the aircraft, particularly on the wing," Culp acknowledges. But he sees the possibility of airframers and engine suppliers working closer together as "quite powerful" for new aircraft developments. "That integration will help us drive both efficiency gains and, we think, ultimately aftermarket maintenance support," he adds. CFM and Airbus plan to assess an open-fan demonstrator in ground and flight tests on an A380 test aircraft by the end of 2029.

The National Transportation Safety Board (NTSB) on 26 May called for changes in the way runway conditions are assessed during heavy rainfall. The current system "increases the risk of a runway overrun", the US agency says. The NTSB has issued three safety recommendations to the US Federal Aviation Administration (FAA) aimed at improving its runway condition assessment matrix (RCAM). Landing distances on wet runways are calculated using the current matrix, it explains. "NTSB recommends the FAA update the RCAM to account for the progressive decrease in the wheel braking friction coefficient, the measure of the slipperiness of the runway, associated with increasing rainfall intensity," the NTSB says. "NTSB also recommends the FAA add additional rainfall intensity descriptors for aviation weather reports to identify rainfall intensities that can exceed the current heavy rain threshold of 0.3 inches per hour. The rainfall intensity descriptors currently used in aviation weather reports do not identify the highest rainfall intensities that are possible at an airport, limiting flight crews' ability to accurately assess the runway condition and the required landing distance." The recommendations follow NTSB investigations of 11 runway overrun accidents and incidents from 2008 through 2022 that occurred after landings on wet runways. In one of those investigations, the 2019 runway overrun of a Boeing 737 in Jacksonville, Florida, the NTSB determined the probable cause was, in part, "an extreme loss of braking friction due to heavy rain and the water depth on the ungrooved runway, which resulted in viscous hydroplaning." Rainfall intensities at the time were two to eight times the heavy rain threshold value, the NTSB says, noting that under such conditions, braking can be reduced to such an extent that pilots should not attempt to land. The FAA tells Cirium: "The FAA takes NTSB recommendations seriously and will carefully consider those issued today."

Ongoing conflict in the Middle East dragged worldwide passenger demand down sharply in April, despite growth in every other region. According to data released by airline association IATA, total global passenger demand fell 3.4% year on year in April. This decline was entirely driven by the crisis in the Middle East, as demand rose 1.2% across the other regions. Global capacity was cut 2.9%, but the passenger load factor slipped 0.4 percentage points to 83.1%. Middle Eastern carriers' demand cratered 47%. They cut capacity 37%, and their load factor contracted 12.5 percentage points to 70.6%. "The situation for air transport remains highly volatile," states Willie Walsh, IATA's director general. "The cost of jet fuel more than doubled in April, which is pushing airfares up. Forward schedule data is showing a reduced offering in the coming months, indicating that airlines are balancing high fuel costs and weaker demand." In international markets, Middle Eastern airlines suffered a 48% year-on-year drop in demand and cut capacity 38%. IATA notes that while traffic remains heavily impacted by the ongoing Iran war, the decline was slightly slower than in March, amid an uneasy ceasefire. The devastation in the Gulf contrasted with fortunes elsewhere. Latin American airlines led international growth with an 8.9% surge in demand, while Asia-Pacific carriers saw a 3% rise. For the airlines of Europe, there was a 0.9% increase, directly aided by a 15% jump in direct traffic between Europe and Asia as passengers replaced routes that had previously transited through the Middle East, notes IATA.