Originally Posted by
Down3Green
You're on here enough to know the tightrope that employees have to walk, so I apologize but I don't want to get into the finer details of a specific procedure. Both the FAA and Boeing have put out some good stuff regarding the go/no-go philosophy of takeoff decisions and you can Google them. However, I know that each airline varies somewhat in their definitions of Hi/Lo speed regimes, specific abort criteria, and callouts and because of that, I don't want to get into word for word procedure. You can probably come up with them, though suffice to say, they eliminate a whole host of items that passengers might consider dire threats.
I also don't want to leave the impression that those of us in the cockpit are somehow disdainful of F/A input. Quite the contrary and I always let them know that during the brief. While we are taxiing out, I want to know if any pax are ill or acting up. I want ot know if snow is accumulating on the wing. I want to know if some engine or aircraft system doesn't sound right. These are all things that they are uniquely able to spot. However, once the First Officer makes the PA for departure and they tell me the 'Cabin is ready for takeoff', any information they have after that point (with the exception of the aformentioned raging cabin fire) is not going to influnce the Abort decision in the high speed regime in any way and will only end up confusing the situation. It's just noise during a time that we try to limit any distractions. At Delta, only the Captain is responsible for the abort decision, and if some abnormal happens, there should be only one of two words you should hear spoken very forcefully by the Captain......either CONTINUE! or ABORT!.The thought of having a conversation with an F/A while rolling along or having them scream STOP is either stunning or amusing.... and maybe both. But I will gladly listen to any concerns they have once we are safely airborne.
Sorry, I wasn't trying to ask for any inside/confidential/proprietary information. I'm just fascinated by the risk assessment behind the abort decision and I was trying to imagine what three things besides big fires would make the decision to abort correct. A subtlety that I wouldn't have thought of is the idea that passengers might unwisely decide to evacuate after an aborted takeoff.
Depending on the location and mass, something on the runway might be an example, but there could be cases where trying to takeoff before the object and go over it could be the right decision.
If something would prevent the plane from climbing as fast as it must, so that it would surely hit a building or a mountain, there could be no choice but to abort, for example if more than one engine were to experience catastrophic failure. Unlikely except due to engine ingestion of large birds?
Maybe the last would be something that could prevent the plane from landing. It's farfetched but an indication that the landing gears won't work perhaps. I'm going to vote for the failure (blowouts) of multiple tires.
Are my guesses at all close? I realize we're talking about very low probability events. Structural failure would also be a factor, but only if it would prevent either takeoff or landing. Also an indication that the pilots will become incapacitated, but not incapacity of one pilot.