JetBlue TrueBlue - Moving Passengers for Balance?

I flew LGB-JFK the other day. The back of the plane was completely full but there were eight middle seats open in the EML rows. After the door shut but before we left the gate, the flight attendants asked if four passengers from middle seats in the rear would like to move to middle seats in the EML rows for balance issues. The pilot then made an announcement they were working out some balance issues also and we would be underway shortly. With such a full flight, did moving these four bodies from the rear of the plane to the front really make a huge difference? Does this happen often?

Probably a bit of overkill here Any effect on Weight and Balance would be minimal at best

Unless there was some reason that the baggage hold wasn't loaded evenly (unusually heavy load toward the rear), then it would be easier to just move the pax forward than to re-distribute the baggage

It matters more during takeoff when the plane it at its heaviest After that, it burns off fuel and gets lighter by the minute

Probably a bit of overkill here Any effect on Weight and Balance would be minimal at best

Unless there was some reason that the baggage hold wasn't loaded evenly (unusually heavy load toward the rear), then it would be easier to just move the pax forward than to re-distribute the baggage

It matters more during takeoff when the plane it at its heaviest After that, it burns off fuel and gets lighter by the minute

I'll reply to this as a JetBlue pilot. First of all, thanks for traveling with us. Second, no overkill at all. We have a weight and balance "envelope" comprised of both weight and balance limits, which we have to be within for takeoff and landing. At JetBlue we calculate this using a program on our company laptops, just prior to gate departure. The program uses the number of empty seats in each section of the plane and the distribution of luggage to calculate the jet's center of gravity. I don't have the option to be "just a little" outside the accepted range, and the location of one person can and does effect this if we are near the limit.

This is every bit as critical for landing as it is for takeoff, and the weight reduction does not directly impact the envelope. In other words, being lighter does not directly change the balance requirements of the jet.

I'll reply to this as a JetBlue pilot. First of all, thanks for traveling with us. Second, no overkill at all. We have a weight and balance "envelope" comprised of both weight and balance limits, which we have to be within for takeoff and landing. At JetBlue we calculate this using a program on our company laptops, just prior to gate departure. The program uses the number of empty seats in each section of the plane and the distribution of luggage to calculate the jet's center of gravity. I don't have the option to be "just a little" outside the accepted range, and the location of one person can and does effect this if we are near the limit.

This is every bit as critical for landing as it is for takeoff, and the weight reduction does not directly impact the envelope. In other words, being lighter does not directly change the balance requirements of the jet.

Is the runway length at LGB also a factor? Also, is BUR a challenge due to the extremely short runway, and need for an accelerated take off?

Sorry for the delay in replying. I fly the Embraer, which does not serve BUR (Burbank), so I'm not completely familiar with the limitations there. I do know that the terrain proximity and short runway length is a performance challenge for BUR. We served LGB in the Embraer until June of this year, and the primary runway 12/30 has 10,000 feet availabe for takeoff. No factor there.