What happened
On July 7, 2023, an Airbus A320-271N operating a scheduled passenger flight from El Loa to La Florida experienced a significant technical failure during the cruise phase. While flying approximately 185 nautical miles south of Calama, the flight crew observed two critical alerts on the Electronic Centralized Aircraft Monitor (ECAM) regarding the number 1 engine: a drop in oil pressure and a decrease in oil quantity.
In response to the deteriorating engine parameters, the pilot in command executed an in-flight shutdown (IFSD) of the number 1 engine. The crew subsequently declared an emergency and requested a diversion to the Andrés Sabella Airport (SCFA) in Antofagasta. The aircraft landed safely at 22:32 local time. All 7 crew members and 174 passengers remained uninjured, and the aircraft sustained no structural damage.
The investigation
DGAC Chile investigators examined the aircraft and its maintenance history following the incident. A post-landing inspection of the number 1 Pratt & Whitney PW1127GA-JM engine revealed visible oil leakage across several components, including the fan case, the angular gearbox (AGB) mast, and the central core.
Detailed borescope inspections identified the specific source of the leak as the tube boss nipple on the oil supply line (identified as LP35) that connects the main gearbox (MGB) to the angular gearbox. The investigation also reviewed the operator's maintenance records, noting that while previous service bulletins had been applied to address similar issues, the leak persisted due to inherent design characteristics of the component.