ANA 737 Evacuated After Engine Oil Alert

All 158 passengers and crew aboard an All Nippon Airways (ANA) Boeing 737 evacuated via emergency slides at Naha Airport in Okinawa on September 24, 2026, after the crew detected high oil temperatures in the right engine during ascent.

Flight 1502, bound for Saga Airport on Kyushu, was climbing after departure from Naha when crew noticed an instrument indicating abnormal oil temperatures in the right engine. No smoke or fire was reported. The crew elected to return to Naha, and the aircraft made an emergency landing at approximately 10:05 PM local time.

After landing, the decision was made to evacuate the aircraft on a taxiway rather than disembark normally. All passengers and crew exited via emergency slides. Three passengers suffered minor injuries during the evacuation. The aircraft was a Boeing 737, though ANA has not publicly confirmed the specific variant involved.

Engine oil temperature events

High oil temperature indications in a turbine engine can signal several potential problems: bearing failure, oil cooler malfunction, oil quantity loss, or a more serious internal engine issue. In a twin-engine aircraft, any engine anomaly that could lead to an in-flight shutdown (IFSD) triggers a cautious response from the flight crew.

The ANA crew's decision to return and evacuate rather than continue to Saga reflects the standard risk-management protocol for engine indications that could escalate. An engine that is running hot may continue to run, or it may fail. Returning to the departure airport gives the crew the option to land on a long runway with emergency services standing by.

This incident follows a string of engine-related events across the global fleet. The Rolls-Royce Trent emergency airworthiness directives issued earlier in September addressed oil pump non-conformities that could cause dual engine shutdowns on A330ceo and 777 Classic fleets. While the ANA incident involves a different aircraft type and engine, the broader pattern of engine oil system events has drawn attention from regulators and operators.

Evacuation procedures

The decision to evacuate via slides rather than disembark through the jet bridge indicates the crew assessed the situation as time-critical. Emergency slide evacuations carry their own injury risk — the three passengers who suffered minor injuries were likely hurt during the slide descent or landing, which is consistent with evacuation statistics across the industry.

Evacuation procedures are trained regularly in CRM and pilot training programmes. The crew must balance the risk of a potential engine fire or failure against the risk of evacuation injuries. In this case, with an engine indication that could not be visually confirmed as safe, the crew chose the conservative option.

Crew resource management training emphasises that evacuation decisions are made by the captain based on available information. The presence of high oil temperatures, without visual confirmation of the engine's condition from the cockpit, is sufficient justification for a precautionary evacuation.

The Boeing 737 fleet context

The Boeing 737 is the most widely operated commercial aircraft family in the world, and engine-related events are not uncommon across the global fleet of thousands of aircraft. Most engine indications do not result in evacuations — they are managed through in-flight troubleshooting, single-engine operations, and normal landings at suitable airports.

However, the ANA event comes at a time when Boeing 737 fleet reliability is under heightened scrutiny. The FAA's 737 MAX bear strap inspection directive and other recent airworthiness actions have kept the 737 family in the regulatory spotlight, even though the structural and engine issues are unrelated.

ANA operates a large fleet of 737s across its domestic network, including both Next Generation (-800) and MAX variants. The airline has not yet published details about the specific aircraft registration or engine model involved, pending investigation.

Investigation and follow-up

Japanese aviation authorities will investigate the incident, examining the engine, maintenance records, and the crew's decision-making process. The investigation will determine whether the oil temperature indication was caused by an actual engine problem or by a sensor anomaly — a distinction that affects how operators across the 737 fleet should treat similar indications.

For ANA, the incident is a reminder that engine reliability remains the single most important operational variable in commercial aviation. The airline's evacuation was executed safely, with no serious injuries, but the event will trigger a review of the engine's maintenance history and the effectiveness of the crew's response.

The broader industry context — including the Trent ADs, the Amazon 21 Air 767 Miami overrun, and the ongoing scrutiny of engine supply chains — means that any engine-related event receives more attention than it might have in a less eventful period. ANA's handling of the evacuation will likely be studied as an example of conservative decision-making under engine uncertainty.