Usually I think of weight-balance issues in connection with RJs, but last Sun. the 6:25 a.m. IAD-SFO, they had to block off the first 2 rows of E+ on a 319. The irony is, I had run across the pilot boarding the bus and found out he was my pilot. I said to him, if you have W&B issues and need to move me to first.... He chuckled.

Now, I wasn't affected by the block-off in the sense that I had decided to stand by for the flight, and so picked 12B (thinking it was exit row). Since I fell asleep prior to take off (when 11B slammed his seat back, I figured that was the best thing to do), I woke up to find 6 & 7 empty. FA explained why and so I wandered back and found the 2nd to last row empty. Sacked out most of the flight.

Even a C5 is affected by weight and balance issues.

All airplanes have weight and balance issues. The center of gravity shifts on a 747 too.

Any aircraft can theoretically have W+B issues. Depends on many unknown (to us) variables, such as cargo weight/distribution, fuel, luggage, and of course, people. Larger aircraft have higher balance tolerances, so you're going to experience a lot less seating changes on those.

With a brother who was a crew chief on a C5, I can absolutely verify that. All planes have weight and balance issues.

Yes, but what's the largest one you've flown on that they had to adjust seating for?

That is a bad stretch of the notion of an 'issue'.

Still not construed enough for folks not to use it. When the HKG gang tried to weigh me, at least post #16 tried to pin their ridiculous behaviour on weight and balancing. And that was only differential weight, not even whole seats, and it was on a 747.

I was on an int'l 777 DEN-ORD in October of 2001 that had a w/b issue. While stopped on a taxiway (why it was identified then, I have no idea), the captain came back and asked some F passengers to move to C. As people started milling around, a guy flies out of Y demanding to know what's going on, throwing a general fit. I'm in the main section of C, watching 2 large male FA's start to crack their knuckles.

FA's get him seated, we immediately turn around for a gate, and get the guy and his bags off the plane and into the hands of armed men. Caused a 2hr delay.

I think weight and balance issues are also relevant to runway length and conditions and other operational factors. Things like engine type and age (both of which vary quite a bit in the same aircraft type) could affect thrust, so I imagine that would have an effect on weight and balance. I've never witnessed it on anything larger than an RJ.

This is a really interesting topic and it would be interesting to see what a pilot has to say about the subject.

Probably best suited in the pilot Q&A thread.... but as long as its the topic here:

Do I remember hearing correctly that weight and balance really only has an effect on takeoff, something like once you hit crusing altitude you can then move back to the seats?

I've been on a 744 delayed departing IAD (for LAX) because they had to shift some of the cargo containers from one hold to the other for weight-and-balance.

I was on an int'l 777 DEN-ORD in October of 2001 that had a w/b issue. While stopped on a taxiway (why it was identified then, I have no idea), the captain came back and asked some F passengers to move to C. As people started milling around, a guy flies out of Y demanding to know what's going on, throwing a general fit. I'm in the main section of C, watching 2 large male FA's start to crack their knuckles.

FA's get him seated, we immediately turn around for a gate, and get the guy and his bags off the plane and into the hands of armed men. Caused a 2hr delay.

I was re-seated on a US Airbus A330-300 a while back for W&B. The Y load was very light while C was full. They moved Y pax aft to get the balance correct.

Around 10 years ago, during the mad cow scare in Britain, I was on a SYD-LAX 744 loaded with a couple tons of Australian beef in the belly (of the plane ). I think the last 2 or 3 rows of lower deck C were reseated. During boarding, those seats had the tray tables out so as to make it clear that no one was to sit in them.

In your case, weighing each pax individually can be construed as an affront to privacy, but I can understand why UA wanted to do it for statistical purposes. I doubt the situation you encountered was for addressing weight and balance on your flight; still, alluding to my own experience, this can well happen on a 747.

I've been on a light passenger loaded 320 with weight and balance issues. They blocked off the first couple of rows of E+ on an early morning flight out of LAS.

I've also been on a 747 to SY with weight and balance issues. They blocked off some of the E+ section and admonished all seat poachers to stay away.