PDXSEP

The weak window here is the middle of the day, not the evening: 11am–2pm runs 80.4% on time against 89.8% for 8pm–5am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 5am–8am window is the busiest, with 1,202 flights scheduled in it.

Across the week, Saturday is the strongest day at 90.5% on time and Thursday the weakest at 79.8%. 11 points is a smaller lever than departure hour, but it is free.

The spread between Delta and Southwest is 15 points, wide enough that it should decide the booking. On a hundred trips that is 15 more arrivals inside the on-time window.

The largest share of delay minutes, 39%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 17,000 of the 44,000 delay minutes reported here. The split is drawn from 43,639 reported delay minutes.

Cancellations are rare at 0.17%, below the national 0.51% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Badly late arrivals are rare here: only 3.2% land an hour or more behind schedule, against 5.4% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.