Cathay Pacific A35k at Hong Kong on Sep 2nd 2024, engine fire

Last Update: September 20, 2024 / 02:10:11 GMT/Zulu time

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Photo of Cathay Pacific B-LXI — Cathay Pacific B-LXI (Photo credit: HawkeyeUK / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Sep 2, 2024

Classification
Incident

Cause
Engine fire

Airline
Cathay Pacific

Flight number
CX-383

Departure
Hong Kong, China

Destination
Zurich, Switzerland

Aircraft Registration
B-LXI

A Cathay Pacific Airbus A350-1000, registration B-LXI performing flight CX-383 from Hong Kong (China) to Zurich (Switzerland) with 332 passengers and 16 crew, was climbing out of Hong Kong's runway 07R when the crew stopped the climb at 9000 feet after receiving a right hand engine (Trent XWB) fire warning. The crew worked the related checklists shutting the engine down and discharging one fire bottle with the fire warning ceasing, dumped fuel and returned to Hong Kong for a safe landing on runway 07L about 70 minutes after departure.

A replacement A350-1000 registration B-LXR reached Zurich with a delay of about 4 hours.

On Sep 3rd 2024 the airline reported following the activation of the engine fire warning, that they have identified an engine component failure and took all their 48 A350s (A350-900 and A350-1000) out of service for a precautionary inspection. A number of such components have been identified needing replacement. A number of flights have been cancelled as result.

According to information The Aviation Herald received a flexible fuel line was damaged, damaged flexible fuel lines were also found in engines of other A350 aircraft during the inspections.

Hong Kong's AAIA reported they are investigating a Cathay Pacific Airbus A350-1041 No. 2 engine serious incident during takeoff from Hong Kong Airport on Sep 2nd 2024.

On Sep 5th 2024 EASA stated they are planning to require a one time inspection of the Trent XWB engines after flight CX-383 on Sep 2nd 2024 suffered an engine fire shortly after takeoff, the fire was promptly detected and extinguished.

On Sep 6th 2024 EASA released their Emergency Airworthiness Directive EAD_2024-0174-E_1 requiring inspections within 3, 7 or 30 days depending on engine hours, engine cycles and shop visits. EASA reasons:

Damage of a fuel manifold flexible tube was reported, leading to a controlled, temporary engine fire and heat damage to the exterior and interior of the engine nacelle (thrust reverser C-ducts). The occurrence resulted in a commanded in-flight shut down. The investigation is ongoing to identify the root cause of the event.

This condition, if not detected and corrected could, in combination with additional failures, lead to a more severe engine fire and resulting damage to an aeroplane.

To address this potential unsafe condition Rolls-Royce issued the NMSB to provide inspection and corrective action instructions.

For the reason described above this AD requires a one-time visual and dimensional inspection of the fuel manifold main fuel hoses.

This AD is considered an interim action and further AD action may follow.

The airline reported the inspection of their other A350s resulted in identification of 15 more damaged fuel lines.

The occurrence aircraft was still on the ground in Hong Kong about 72 hours after landing back.

On Sep 19th 2024 EASA released Airworthiness Directive AD-2024-0182 superseeding previous AD 2024-0174-E and reasoning:

Damage of a fuel manifold main fuel hose, leading to a controlled, temporary engine fire and heat damage to the exterior and interior of the engine nacelle (thrust reverser C-ducts), was reported. The occurrence resulted in a commanded in-flight shut down. The investigation is still ongoing to identify the root cause of the event.

This condition, if not detected and corrected could, in combination with additional failures, lead to a more severe engine fire and resulting damage to an aeroplane.

To address this potential unsafe condition Rolls-Royce issued the NMSB Trent XWB 72-AL165 to provide inspection and corrective action instructions for certain Trent XWB-97 engines and EASA issued EASA AD 2024-0174-E to require a one-time visual and dimensional inspection of the fuel manifold main fuel hoses.

Since EASA issued AD 2024-0174-E, in-service and in-shop inspections have identified that a specific cleaning process available during engine refurbishment may lead to fuel manifold main fuel hose degradation.

Additionally, it was determined that Trent XWB-75, Trent XWB-79, Trent XWB-79B and Trent XWB-84 engines were also the subject of the suspect cleaning process, and therefore are potentially affected by the unsafe condition addressed by this AD.

Prompted by this development, the affected cleaning process was discontinued by maintenance organisations as instructed by Rolls-Royce Maintenance Repair and Overhaul Quality Alert No. MRO 2024-21 issue 1. Additionally, Rolls-Royce issued the NMSB, as defined in this AD, to provide repetitive inspections for populations of engines potentially affected by the suspect fuel manifold main fuel hose cleaning process.

For the reasons described above, this AD partially retains the requirements of AD 2024-0174-E, which is superseded, and requires repetitive inspections and corrective actions for affected populations of engines. This AD also introduces restrictions for installation of the affected parts, engines equipped with the affected parts, and requires reporting of inspection results.

On Sep 19th 2024 Hong Kong's AAIA released their preliminary report summarizing the sequence of events:

The aircraft took off from runway 07R at VHHH at 00:24:10. Shortly after liftoff, with the landing gears retracting at 00:24:52 (radio altimeter height: 34 ft / airspeed: 191 kts), the flight crew observed an 'ENG FIRE' warning for the No. 2 engine. The crew immediately executed the ECAM3 procedures, shutting down the No. 2 engine and discharging one fire extinguisher bottle (Agent 1). The fire warning for the No. 2 engine was cleared after 59 seconds.

The flight crew initially declared a MAYDAY but later downgraded the status
to PAN. To meet landing weight limits, they initiated fuel jettison after
coordinating with HKG ATC. The aircraft landed on runway 07L at 01:40:29.
No crew or passengers were injured.

The post-flight examination of the No. 2 engine conducted by the AAIA revealed that the steel braided sheath of the fuel hose (secondary fuel manifold hose) connecting to the No.17 fuel spray nozzle had a rupture, evidenced by a discernible hole in the hose. Additionally, black soot was observed on the aft section of the core engine, indicating signs of a fire. Burn marks were also noted on the underside of the two thrust reverser cowls.

In addition to the anomaly identified on the No. 17 secondary fuel manifold hose, five additional secondary fuel manifold hoses were found to have either frayed metal braids or collapsed structures inside the hose.

Further inspection suggested that fuel directed to the fuel spray nozzle could leak through the ruptured secondary fuel manifold hose. Coupled with other contributing factors, such as the presence of oxygen and an ignition (heat) source, this could result in a fire that could spread to the surrounding area.

If not promptly detected and addressed, this situation, along with further failures, could escalate into a more serious engine fire, potentially causing extensive damage to the aircraft.