Welcome to the logistics side of the airline where behind the scenes dispatch/flight & airport ops work together to handle irregular operations.

To answer your question, it depends on the situation and aircraft issue.

The resources available at LHR are way different than STT. Just picked two random airports but you get the point.

Thank you! I find the complexity of these nuances fascinating...one of the things I love about the industry.

Usually, not very much. Most strikes don't produce any damage other than small burn holes at the entry and exit points. Initially, we'll monitor systems to see if the strike caused any system issues then we'll write it up for a maintenance inspection. A divert would only be needed if the strike caused some system issues.

I don't know what's involved in the inspection but we have maintenance, either in-house or contract, at every station. The inspection shouldn't take too long.

Thanks for the explanations! -- It was pretty much what seemed to happen. Have you ever seen or heard of issues after a strike that led to diversion? Just curious.

Several years ago, I was flying from ORD to LAX on an AA 787. Even though the plane was already at the gate, boarding was significantly delayed for an inspection due to a lightning strike on the inbound flight. They then had to reboot the computers, which took at least another 20-30 minutes. IIRC, we were delayed for at least an hour.

Over in the cancellations/diversions thread, there was this cause listed:
This sounds unusual, as diversions go. What might have changed for weather since departure to necessitate a return to field?
https://www.flightaware.com/live/fli...355Z/RKSI/RKSI

No - as clubord said - the Scheduled Flight Time provides the thresholds for augmented staffing. If a trip to Europe from the east coast is 7.25 hours and the return is 8 hours and 5 minutes, we're going to augment in both directions - once one direction is over 8 hours, both directions get augmentation. The fact a flight is domestic or international doesn't play into this.

There are very specific regulations for augmentation and there is a formula for how long each pilot works and rotates into an operating position/relief position. If you're really curious, and have time you can read all about it here: https://www.ecfr.gov/current/title-1...ter-G/part-117

Weight and balance question
 

I was on a 787 recently (United) and there were a few empty seats. Before we left the gate, the flight attendants started moving people around, including to the front of the cabin. I thought they were probably rescuing people from middle seats. Then, while we were taxiing, the pilot says we're going to pull over. The flight attendants then went around and made everyone go back to their assigned seats because of balancing problems.

Is this normal? Why did the flight attendants do this (i.e. moving people around before takeoff)? How did the pilots even know that the plane was out of balance?

They managed to get the disgruntled passengers back to their seats by promising they could return to their comfy seats after takeoff, but later on it was announced that everyone had to stay where they were for the whole flight. Not everybody complied.

Thanks in advance for any enlightenment.

The flight crew are informed of the weight and balance when they get a copy of the load sheet from Ops. This is finalized after loading the pax and assumes people are sitting in their assigned seats. The only way the flight crew would have known of the pax moving is if somebody from the cabin crew told them, which somebody obviously did.

The aircraft weight and balance is a critical factor in safe flight. Obviously if the aircraft is overweight it takes a lot more runway to take off (if it takes off at all), the performance and handling is adversely affected and the tires and landing gear can be over stressed. When the balance is out (as potentially in this case) it makes the aircraft either nose heavy, or tail heavy. Both are equally as dangerous. When nose heavy it makes it difficult or impossible to “rotate” the aircraft during take off, preventing it from taking off. When tail heavy, the aircraft can over rotate before the critical speed is reached on take off, which effectively aerodynamically “stalls” the aircraft, again, preventing take off.

The load sheet has to be an accurate representation of the aircraft weight and balance, and any changes need to cleared with the flight crew. Obviously on a lightly loaded aircraft, there will be a lot more latitude before weight and balance limits are reached than on full pax, max fuel flight, so moving a few pax around will be acceptable.

if you think about airline planning weights of 190lbs (summer) and 195lbs (winter) per pax and think about the people you know, there has to be a reasonable safety margins built in to performance calculations.

A load master in Chicago gets the data from the passenger closeout and the cargo loading closeout. If everything is within limits, the final weight message is delivered via ACARS. If there is an issue, we'll get an ACARS message telling us what has to be done to resolve the problem. When it is a CG problem, the message will say to move a specific number of passengers from one specific row to another specific row or to ensure that a particular row(s) is unoccupied. We won't get our final weight message, which we need to finalize the takeoff data, until we've replied that the changes have been made.

as others have shared, could have been a misunderstanding for the initial move then the correction to move back based on what they shared with the cockpit and if it was out of variance.

I'm still mystified why the flight attendants were moving people around before takeoff. Didn't they know that could cause problems? It can't be the first time this has happened, surely. I'm glad the flight crew took action.

Every time I've seen FAs moving people (in the US and elsewhere) it's been well before takeoff -- usually before door close -- presumably so that if someone needed to be offloaded or "persuasion" from a GA that can be done quickly. I'm guessing as CALMSP mentioned it was a miscommunication re: what needed to be done or when people should be moved around.

I can't imagine it was a bunch, would need OP to share maybe a little more. Hard to believe a 787 was so wide open and pax variance was out.

i resemble that last statement ….:)