Defueling delay
 

We had a strange experience on UA 294 yesterday from SEA to SFO. The passengers were all boarded and then the captain announced that we had to wait to have 9,000 lbs of fuel removed, because the plane was originally intended to fly to IAD. We sat on the plane for about 30 minutes before the fuel truck arrived. We almost missed our connecting flight and many others had tight connections well.

It amazes me that United didn't realize the fuel needed to be removed sooner and take action to preclude disrupting connections.

Had the same issue at SFO last year on a SFO-DEN flight. We were delayed two hours on that one. On the bright side, 4 F pax deplaned due to missed connections, bumping us to First. And we got to meet hobo13 and family.

I've had a couple of flights where they didn't figure it until we were on an active taxiway, and they ended up sitting there burning fuel for awhile.

I'm surprised they were concerned about hotels for a 1 hour delay in the morning.

odd... is this an max gross landing weight issue or something else?

Better than tossing 9,000lb of pax and bags, I suppose! ;)

In all seriousness, the fuel trucks are on schedules too. When UA decided to swap the a/c, for whatever reason, they likely contacted the vendor to get a truck out to offload fuel. 9k lbs is roughly ~1300gal, so it probably took some time to get an empty tanker out to the airplane.

That could probably apply to any flight misconnects at SFO today. Bay to Breakers in the morning plus AMGEN Tour of California heads from San Francisco to Santa Rosa.

Not uncommon. As others note it takes time to find empty trucks, divert them to an overweight aircraft and take care not to louse up the fueling schedule for the other aircraft. Unless someone has facts which suggest that there was an empty truck available earlier, I would suggest that commercial aviation operations aren't quite as simplistic as some think (or don't).

Maker Faire is at San Mateo Expo, too. I hear they tied up the entire Foster City Crowne Plaza with just staff and exhibitors coming into town, not to mention attendees.

Happened to me last year. Midnight flight from Lax-Iah... They sat on the ground. Burned fuel. Took off. Realized they burned too much. Went back to Lax to get more. Obviously I missed the connection.

Why in the world burn fuel rather than just haul it along?

Too much fuel, too much weight.
Generally not recommended for safe landings.

Very odd indeed, given that the morning SEA-IAD was a sCO 739 on this date.

Quite true. There are tons of behind-the-scenes things that few people have a clue about. Not unlike most things that aren't in our immediate field of expertise.

FAB

Without facts, it's all speculation, but here's a little: could be that the A/C swap happened soon before, leaving little time and few resources to defuel. Often, if minimally overfilled, it's not cost-effective to defuel so we will burn it either before takeoff or while enroute, assuming the problem is overweight landing downline. Burning an extra 9,000 between SEA and SFO is not going to happen, though.

FAB

Often times yes. Planes can be limited by weight in many dimensions. Maximum zero fuel weight, ramp weight, taxi weight, takeoff weight, landing weight. If the aircraft in this scenario had a high payload and was fueled for a longer flight and then subsequently switched to a shorter flight, the issue very well could be the possibility of exceeding the maximum landing weight. Many transport category airplanes are certified to takeoff at one weight but must (under normal operations) ensure they land at a weight which is often times thousands of pounds lighter than the maximum certified takeoff weight.

Say a plane can take off at a maximum weight of 200,000 lbs but may only weight 150,000 lbs for landing. Now imagine this plane is scheduled to operate a flight where the fuel burn will be 20,000 lbs. Even though the plane is capable of taking off at 200,000 lbs, in this scenario the airplane may only take off at 170,000 lbs (maximum landing weight + fuel burn).