[chulk90]

Here's some insight:

The recent deregulation worldwide has sparked a huge increase in the # of low-cost airlines, resulting in a spreading out of passenger load across airlines. Therefore, there aren't as many passengers to carry per airline as before, and A380s and even B747s are no longer needed. In fact, all of the U.S. airlines (Delta, United, American, and smaller ones) are either phasing out or parked all of their jumbos.

Side effect:

Because of the # of increase, air traffic has worsened (e.g. delays at airports) and pollution has increased very rapidly.

[BorgHunter]

> In fact, all of the U.S. airlines (Delta, United, American, and smaller ones) either sold or parked all of their jumbos.

This is not true quite yet, although it will be true in a couple years. United and Delta still operate a handful of 747s on their densest routes, but they're in the process of being phased out. Here are a couple flights:

https://flightaware.com/live/flight/UAL59/history/20160914/1...

https://flightaware.com/live/flight/DAL278/history/20160914/...

[forrestthewoods]

> pollution has increased very rapidly.

Citation? Lots of comments in this thread seem to imply the opposite. Two engine planes more efficient than four engine. Fewer empty seats. More direct paths between cities; less routing through hubs.

[aidenn0]

I fly in the US transcontinental fairly regularly and have never been on a wide-body aircraft for it. The largest plane I've been on was the longer version of the 757. Usually it's more like a 737 or A320 variant.

I find it rather odd because for my most common flight leg (LAX<->IAD) There are a minimum of 7 flights per day on United. I would have thought they would save money by combining some of those.

[chulk90]

737s and 320s are really popular for short-range flights, while 777s and 330s are the go-to choices for long-range flights.

[jkot]

Four engine aircrafts are also more difficult/expensive to maintain. Most pilots prefer two engines.

[Symbiote]

I'm curious, why would a pilot working for a commercial airline care about the maintenance cost or difficulty?

[jkot]

Two engines have more spare power than four engines. Single engine on twin must still be able to fly aircraft.

[sp332]

Because they have to sit and wait every time there's an unexpected delay on the tarmac.

[tormeh]

Can't you just increase the required passenger-mile per gram of CO2 to fix the pollution?

[loeg]

Or increase the CO2 fee.