On my flight yesterday from BOS to LHR, I was booked into 21A, and up until about 1 minute before we took off, it looked like no one was going to sit in the aisle seat, however, the person in 20B realized that no one was sitting in 21B, asked and then she moved over.

Since the AAngel may have blocked the seat for me, when she asked if anyone was sitting there, could/should I have said that it was blocked for me?

Or should I have simply moved over to 20B, put my backpack on 20A and then made it appear that both seats were taken?

What's the normal etiquette in this situation? I don't want to be rude to anyone and can totally understand moving 20B to 21B.

It's just the luck of the draw. Empty seats on a flight are up for grabs once the door shuts. If you want an empty seat next to you then perhaps go for a window seat in a less attractive row.

I had a similar frustration on a BA flight from ALG-LHR. Found my F window seat occupied. The muppets in DEF had boarding passes for ABC. Meanwhile, D had shown up and decided to go to A. So the people who should have been in ABC decided to go to CDE, leaving the vacant seat at B that should have been next to me in E. That's life.

Trying to block ANY empty seat is incredibly rude. If someone wants to change seats and they have a seat in the same cabin, they are permitted to do so. For purposes of this rule, "Economy Plus" on United should be considered a separate cabin (i.e., you do not have a right to move from Economy Minus to Economy Plus).

Your backpack should have been under the seat.

I think this is more of question about etiquette on a long haul flight, where you want the extra seat to be able to sleep better than just a question about etiquette about the exit row. If it were me on a domestic flight I likely would not have even cared, but since this was an overnight flight where a little more sleep makes a difference the next day then I would have tried to sit in the aisle seat making the window seat look less attractive for someone to move. I disagree with others that say seats are open for grabs when the door shuts. If people really wanted that seat then they should have picked it when getting their boarding pass or at the gate. If they couldn�t then it should not just be up for grabs. If your airlines blocked it then they blocked for a reason and it should stay that way.

I assume that you were on either a 767-300 or 777-200 with two seats on each side. Generally, once it looks like most of the paxs are onboard (when I am stuck back in Y) I will lay reading materials, Ipods, etc. on the aisle seat to discourage seat poachers. If a late arriving pax comes along, often a standby getting a seat at the last minute, I of course just move my stuff. I agree if that pax wanted 21B she should have requested 21B. This situation would different on a 737 or 757 with three seats where a person is stuck in the middle and now has the chance at a better seat but there is still one empty seat to share between two paxs.

I don't think any airlines block seats anymore, especially on transatlantic in coach. I also don't see what the real problem was since the armrest is fixed so it's not like you could stretch out. if you had wanted the aisle seat then you should have booked it. 20B is a less desirable seat than 21B because of the legroom, recline and no storage space.

If the airline blocked it that's one thing, but if it was a free seat then surely your rule above should apply to EVERYONE - i.e. if the OP wanted 21B he should have booked it in the first place too.

To me, anyway moving to an empty exit row seat is understandable - they're desirable seats to most. In a standard row, if there is one empty seat then I agree that it would be unusual (and I would be annoyed) for a pax to move there from somewhere else as they're not gaining anything, but it's certainly not my place to do or say anything to prevent it - why shouldn't they?

Coupla thoughts:

• most people wouldn't know 21B was a desirable seat until they saw it - they don't walk around with mental seat maps
  
• if airlines didn't want people to seat hop then they might tell their FAs to stop saying yes every time a passenger asks if they can

I always thought the airlines wanted exit row seats fully occupied, so that there is help available in case of emergency.

WRXMOM, if she knew that the aisle seat was blocked, should have sat in the aisle seat. Rarely do last minute moves before takeoff try for a window seat over seated passengers. If she was unaware if it was blocked, or if it unblocked by the GA because of a full flight, she would scoot over when a pax with the seat assignment shows up. Otherwise an open aisle seat is in play if someone wants it.

Years ago on AA GRU - MIA, I had the agent put me in the middle seat, middle section of 5 seats across. He blocked the 2 seats on either side of me. I put as many items across all the seats and saw several people eye the end seats, getting ready to jump immediately after door closure, but I was able to block their move by physically moving to the end seat that they were eyeballing and leaving my stuff in the other end seat. This led to enough confusion as to which seat I had that I was able to lift the 4 arm rests and stretch out immediately across all 5 seats after takeoff, even though the flight was more than half filled. Better than F in my opinion.

-outoftown