Grounded by a Grain

On 24 February 2025 at 09:30, a Boeing 787-9 from one of our clients arrived at Paris CDG Airport. Upon arrival, the captain reported to our engineering team that an “ENG OIL DMS” fault message had appeared during the flight. This alert could indicate either a defective magnetic chip detector or an abnormal presence of metallic particles in the oil system, requiring further investigation.

In coordination with the Maintenance Control Center, one of our technicians removed the magnetic chip detector, which confirmed the presence of particles. These were collected, the detector was reinstalled, and two five-minute idle engine runs were performed to check for additional debris. No further particles were detected. Nevertheless, the aircraft was declared AOG at 14:00.

The MCC decided to send the collected samples for laboratory analysis on the next day’s flight, as no immediate testing capability was available on site. In parallel, the oil pressure and scavenge filters were inspected. No particles were found, but the filters were replaced as a precaution and sent along with the samples for analysis.

To precisely identify the internal source of the contamination, Rolls-Royce recommended the installation of ten magnetic plugs at strategic points within the engine. These were couriered within 48 hours and installed immediately. The procedure required an idle engine run followed by four dry cranks. The plugs were then inspected individually, which allowed the team to trace the origin of the debris to the Tail Bearing Housing. A request for Technical Variance was submitted to Rolls-Royce in order to obtain a flight release.

On 27 February at 16:15, Rolls-Royce granted authorization for three flight cycles. The magnetic plugs were removed, the standard blanking plates reinstalled, and a final engine run confirmed full system integrity with no leaks observed.

After the necessary routine checks, the aircraft departed on a ferry flight on 1 March at 12:00.

This successful intervention highlights the expertise, responsiveness, and commitment of our teams to ensuring the highest standards of safety and reliability, even under AOG conditions.