How do Cathay Pacific pilots fly with one engine?

All Cathay Pacific’s passenger aircraft are twinjets, meaning they’re powered by two engines. But what would happen in the unlikely event one stopped working? It’s a question explored routinely in simulator training, preparing pilots for a situation that is manageable, safe and exceptionally rare.

“Modern jet engines are so reliable that most pilots will never experience a failure throughout their entire career,” says Cathay Pacific Head of Line Operations Captain James Toye.

Preparation for all eventualities, however, is key. There are two main scenarios pilots train for: an engine issue at altitude and one during take-off. “In every regulatory simulator session, we practise an engine failure at the most critical point, which is just as the aircraft is about to lift from the runway,” says Line Operations Manager Captain Tony Pringle.

“At that moment, the aircraft has very little energy, around what we call the decision speed, or V1.”

V1 is calculated for every flight, reflecting factors such as aircraft weight and weather conditions. Until this point, there’s ample runway available should the aircraft need to remain on the ground. Beyond it, the aircraft is already fully committed to a safe departure, continuing exactly as designed.

The reassuring reality is that this situation is exactly what aircraft are built to handle. “All of our aircraft are capable of climbing away from the runway on a single engine and continuing the flight smoothly,” Captain Pringle explains. It’s still categorised as an emergency, simply because one layer of built-in redundancy has been removed, not because the aircraft or its passengers are in any danger.

The second scenario occurs at altitude. Aircraft are heaviest at the beginning of a journey due to fuel on board. “If a wide-body aircraft experiences an engine shutdown at altitude while heavy, it may not be able to maintain its cruising height straight away,” says Captain Pringle. “Instead, it will gently drift down to a lower level. Our job is to ensure that altitude remains safely above any terrain below.”

From there, the plan would be to divert and land. This requires additional planning on long over-water routes, but Captain Toye explains that Cathay Pacific’s ultra-long-haul aircraft are certified for extended diversion time operations, or EDTO, of 240 minutes. “When we plan a flight, we calculate the furthest point we would be from a suitable airport and ensure we can reach it comfortably should one engine be shut down,” he says.

If it ever happens – and it most likely won’t – the aircraft, systems and crew are more than ready.