905 Li-ion Thermal Runaway

Li-ion thermal runaways in aircraft cabins, Ryanair engine blade-out accident, two planes with the same flight number at the same airport at the same time, Marine One and commercial operations at DCA, Air India crash report update, Boeing 737 Max crack inspections, hiring gamers to become air traffic controllers, and the Heart Aerospace X1 battery-electric demonstrator first flight.

Aviation News

Li-ion Thermal Runaways on the Rise in Aircraft Cabins

UL Standards & Engagement (ULSE) issued a 2025 Data Review, Lithium-ion Battery Incidents in Aviation [PDF, 13 pages]. The study reports a 15% increase in Lithium-ion battery thermal runaway incidents on passenger flights in 2025, compared to the year prior. Portable charger incidents increased 42%, ahead of e-cigarettes, with cell phones the third most common device involved in thermal runaways.

The data comes from the voluntary ULSE Thermal Runaway Incident Program (TRIP). More than 40 passenger and cargo airlines participate in the program. These incidents cost the industry an average of $1.8 million a year, or $96,000 per incident, “in damage, disruption, and associated losses.”

To mitigate the risk of thermal runaway incidents, ULSE recommends cabin crew training, standards for onboard safety equipment to help manage thermal runaways, and more passenger education.

Bird strike suspected in Ryanair engine blade-out accident

In July, a Malta Air Boeing 737-800, doing business as Ryanair flight 1879, experienced a No 2 fan-blade-out failure as it climbed out of Thessaloniki International Airport in Greece. Engine fragments breached the fuselage and the cabin depressurized. A passenger was partially sucked out through a window that blew out.

In its Aviation Investigation Preliminary Report [PDF, 13 pages], the NTSB reports:

“Examination of the airplane revealed that the No. 2 engine, an CFM International (a joint company between Safran Aircraft Engines and GE Aerospace) model CFM56-7B26, experienced a fan blade separation that resulted in engine fragments striking the fuselage and the right horizontal stabilizer. The pressurized section of the fuselage was penetrated 1) through the passenger cabin window located at row 11, as well as 2) lower lobe fuselage skin behind the right wing-to-body fairing… Additional impact damage was found on the right wing-to-body fairing, a dent with paint smearing on the fuselage window belt skin, a dent on a stringer common to the dented fuselage window belt skin, a gouge on the right horizontal stabilizer upper skin and a dent on the right horizontal stabilizer leading edge.”

View of the No.2 (right) engine inlet. View is looking aft..Courtesy NTSB.

“Examination of the engine and nacelle revealed that one fan blade (No.10) had fractured and separated below the blade platform. The outer blade tips were fractured and separated on two additional fan blades (Nos. 16 and 21). All remaining blades were full length but exhibited varying levels of impact deformation. Three loose fan blade fragments were recovered from the engine. A visual examination of the core was performed and there was no evidence of radial uncontainment though the engine cases, or any undercowl fire. The engine inlet cowl, which is forward of the fan case, exhibited evidence of punctures…”