European regulators have widened the number of Rolls-Royce Trent engines potentially affected by a fuel hose defect, in an updated safety directive issued 19 September following an engine fire on a Cathay Pacific Airbus A350-1000 earlier this month.
The European Union Aviation Safety Agency (EASA) has also identified a “specific cleaning process” during engine refurbishment as a likely cause of the damage to the manifold fuel hose on the Trent XWB-97 engine powering the Cathay jet.
On 2 September, the Cathay A350 (B-LXI), operating as flight CX383 from Hong Kong to Zurich with 332 passengers and 16 crew aboard, suffered a fire in its number 2 engine shortly after take-off. The fire was cleared after 59s, and the aircraft returned to Hong Kong 1h 15min after departure.
A preliminary investigation report by Hong Kong’s Air Accident Investigation Authority – issued hours before the EASA directive – found that a ruptured fuel manifold hose was the likely cause of the fire.
Post-incident examination of the engine revealed that another five secondary hoses were “found to have either frayed metal braids or collapsed structures inside the hose”.
EASA’s updated directive on 19 September supersedes an earlier order for a one-time inspection of the fuel manifold hoses for A350-1000 operators.
EASA states: “In-service and in-shop inspections since then have identified that a specific cleaning process available during engine refurbishment may lead to fuel manifold main fuel hose degradation.”
The agency also found that more Trent variants were “subject to the suspect cleaning process”, making them “potentially affected” by the “unsafe condition addressed by this airworthiness directive”.
These include the Trent XWB-84 that powers the smaller A350-900. EASA also includes the lower-thrust Trent XWB-75 and XWB-79 variants in its order – models originally developed for the abandoned A350-800 but in-service on a handful of -900s, Cirium data suggests. The EASA directive does not indicate how many engines are affected.
The cleaning process has now been discontinued by MRO organisations, and Rolls-Royce has updated its service bulletin to mandate repeat inspections for engines potentially affected.
For the Trent XWB-75, XWB-79 and XWB-84 engines, EASA has ordered inspections within 30 days, with subsequent checks at intervals of not more than 2,000h.
EASA’s earlier directive called for older XWB-97 engines – those with 18,500h or 2,300 cycles, and which have undergone at least two shop visits – to be inspected within three days. Younger engines have an inspection timeframe ranging from seven to 30 days.
