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What does it mean to say that regulators are “nervous” about ETOPS? Regulators are always nervous; that is their job. If they permit something it is because the

What does it mean to say that regulators are “nervous” about ETOPS? Regulators are always nervous; that is their job. If they permit something it is because they have determined it is safe enough. It’s really weird to imply that losing one engine is a ditch situation. Modern airliners can take off on one engine. ETOPS 330 certifies them for operation on one engine for 5.5 hours continuously. They may have to descend a bit from max altitude but there’s a big difference between that and ditching. More flights have experienced fatal crashes due to pilots flying a perfectly functional airplane into the terrain, than from both engines failing. On objective evidence, you should be more worried about the pilots than the engines. “It’s a 4-engine ocean” is indeed an old expression.

redis_mlc 6y ago
Your comments are both superficial and unhelpful. > they have determined it is safe enough. This is a common misconception. Regulators believe ETOPS is safe enough based on engine reliability before an actual flight loses an engine. Then it's an emergency. The probability of the engine failure goes from almost 0.0 to 1.0. See the difference? > It’s really weird to imply that losing one engine is a ditch situation. I didn't say that was a certainty, but it is more likely to be a ditching situation for several reasons. The lower a jet flies, the more fuel it consumes. If there's also a pressurization problem, descending to 10,000 feet would rapidly burn fuel. Also, operating a jet engine at maximum power increases the likelihood of failure, and by itself is more risky. > Modern airliners can take off on one engine. You cannot plan a passenger flight for takeoff on one engine for safety reasons. Not all airplanes will successfully be able to clear obstacles on one engine. The only time it's allowed to takeoff on one engine with passengers is after V1. > “It’s a 4-engine ocean” is indeed an old expression. It's still true. ETOPS is for cost-minimization, not safety. It's always safer with 4 engines than 2. IOW, you don't know anything about the topic, like virtually all HN readers. Just because the risk of ETOPS has been normalized, it doesn't mean that it's as safe as 4 engines.

redis_mlc 6y ago

Your comments are both superficial and unhelpful. > they have determined it is safe enough. This is a common misconception. Regulators believe ETOPS is safe enough based on engine reliability before an actual flight loses an engine. Then it's an emergency. The probability of the engine failure goes from almost 0.0 to 1.0. See the difference? > It’s really weird to imply that losing one engine is a ditch situation. I didn't say that was a certainty, but it is more likely to be a ditching situation for several reasons. The lower a jet flies, the more fuel it consumes. If there's also a pressurization problem, descending to 10,000 feet would rapidly burn fuel. Also, operating a jet engine at maximum power increases the likelihood of failure, and by itself is more risky. > Modern airliners can take off on one engine. You cannot plan a passenger flight for takeoff on one engine for safety reasons. Not all airplanes will successfully be able to clear obstacles on one engine. The only time it's allowed to takeoff on one engine with passengers is after V1. > “It’s a 4-engine ocean” is indeed an old expression. It's still true. ETOPS is for cost-minimization, not safety. It's always safer with 4 engines than 2. IOW, you don't know anything about the topic, like virtually all HN readers. Just because the risk of ETOPS has been normalized, it doesn't mean that it's as safe as 4 engines.