As others have mentioned, boarding methods are a big contributor. WN's unassigned seating is the fastest way to board a plane.

But I wanted to add that United's WilMA method is faster than the back-to-front method used by other airlines (AS, AA, DL, etc.):

https://jonathanbecher.com/2017/02/1...ard-airplanes/
https://mythresults.com/airplane-boarding

So UA is actually (slightly) better than just about everyone else aside from WN. UA is also more aggressive with pushing back before final W&B numbers are calculated -- one of my infurating annoyances with AS is that they wait to push until all of the numbers are in, which often results in boarding ending 20 minutes before scheduled departure but the plane not actually pushing back from the gate until 5 minutes after scheduled departure.

Was an 321neo flight from FLL-ORD earlier this week. After we taxiied to gate, the pilot comes on the PA and says "we have a bit of a weight-balance issue and need to remove a bunch of bags before opening the door. Otherwise we run the risk of the tail tipping."

Knowing the 737-9 series has a similar risk and uses a tail stand, is there not something similar for the 321neo? It wasn't a huge deal, but it was an extra 15 minutes we had to wait for bags to get unloaded.

have not seen a tail tip chart for the 321 before. Certainly can happen, just nothing near the 739 which was previously at 3,000 lbs as the limit in the aft with nothing in the front.

There is not a Tail Stand for the A321 but there are procedures for alerting Ramp on arrival of an aircraft at risk of a tip. They must follow those procedures before passengers can disembak. As you might imagine, the crew is also aware of the risk and communicates to mitigate it with other team members.

I had this happen too. The captain said it happened on the previous flight as well.

Has something changed about the way they load this plane? I have had several A321 flights in the past without any issue raised.

it can/has/does happen after the flight is closed out and departed at origin. For example with the 739, load planner will advise load 75 local bags in bin 2, then transfers and remaining bags in bin 3. If bin 3 then exceeds the ratio of what is required in bin 2 to have in bin 3, you'll have to unload X amount of bags in bin 3 to offset the imbalance while unloading. Now when this happens, it's still within the acceptable envelope to fly the aircraft within its limits, this is just a limitation related to the a/c on the ground while unloading.

Altitude question:

UA261 MAD-IAD the crew had Channel 9 on (thank you! -- fantastic to hear the entire journey of the flight rather than just the activity around a specific airport as I usually hear it)

Not long after we hit land on the North American side of the Atlantic, around the handoff to Moncton center we were getting continuous light chop with occasional moderate and from the sounds of it everyone else at 35,000 around the same time was experiencing the same thing.

I always assumed (I know) that ATC just assigned the altitude but noticed ATC offered a variety (IIRC, 34, 37, and 38) -- our flight went down, others went up (with a few requesting and being granted 39 and 40) -- what kind of factors go into making that decision? And is there any kind of significant performance/fuel impact +/- a few thousand feet or would they all be about the same?

Bonus question what does "nonstandard" in the context of "VFR nonstandard 6,000" mean? (Heard as I was typing the primary question :) )

There is an optimal altitude for your airplane at the specific temperature and weight. All else being equal, we'll want to fly as close to that optimal altitude as possible. As we burn fuel, our weight decreases, and our optimal altitude increases. We'll periodically requires climbs to stay as close to our optimal altitude as possible.

All else is never equal, however. Some altitudes will be turbulent, others may have icing conditions, other will be unavailable due to traffic. We'll also have a maximum altitude, based on weight and temperature, that we can't exceed.

That is the hemispheric rule, 14 CFR 91.159.

Magnetic courses of 000 through 179 fly an odd-thousand plus 500. 180-359 fly an even-thousand plus 500.

IFR aircraft in uncontrolled airspace fly the same even/odd thousand but without adding the 500'. In controlled airspace, we fly whatever is assigned by ATC but they almost always use the hemispheric rule with few exceptions such as north/south in Florida.

Above RVSM airspace (>FL410) the spacing increases to 2,000' increments.

I noticed that red-eyes eastbound transatlantic flights can fly odd or even flight levels over oceanic airspace (probably because there are usually no westbound flights at that time of the day). I remember listening to Channel 9 on a LHR-bound flight at FL360 and as we neared Europe heard ATC asking our pilots to choose an odd-thousand level.

For UA261 today (11:15 AM Madrid local departure) around the time "Madrid" was handing us off to Shanwick (sp?) several other flights were given a "must request an [even/odd] altitude prior to..." direction (that was ~14 hours ago and I haven't slept so my memory is very unclear other than my brain keyed on that phraseology -- it was also interesting to hear all of the other UA, AA, and DL flights checking in (and looking at where the UAs were going to/coming from -- I know I saw/heard BCN-IAD, MAD-EWR, LHR-IAD, AMS-???

But I also got an awesome view of and photo of the Speedbird that was paralleling us for a good while...

Simple answer…

Over the oceanic tracks (non radar) you can fly any published even/odd altitude for a given route.

Once approaching land and entering a radar environment; “Shanwick” for Europe or “Gander” for Canada we must comply with the direction of flight even/odd altitudes for separation.

The North Atlantic Tracks alternate east bound/west bound twice per day. Each NAT track message lists the available altitudes for the direction of flight.

Here's the latest NAT message.

https://www.notams.faa.gov/common/nat.html

Operation Questions
 

Have an operations question with respect to how long a pilot can be on duty in a day. Here is the aircraft routing for today.

UA 3750 DEN-SMF departs 135PM
UA 3778 SMF-CLE
UA 3751 CLE-DEN arrives 308AM

Flight hours 10.30
Duty time 13.5 but I assume duty time starts 1 hour before the DEN departure so they would add at least another hours. Is this a legal duty time or maybe there is a crew change last segment but most charters return aircraft to point of origin.

That's an unaugment trip (two pilots).

For a 3-leg duty period reporting between 12:00n and 12:59pm, the crew would be limited to a 13 hour duty day

For a report time from 5:00am to 7:59pm the flight time is limited to 9 hours, which is the maximum for an unaugment crew.

Duty time start 60 minutes before scheduled departure for the first flight of a trip pairing and 45 minutes after a layover.

That looks like a baseball charter. Neither the duty time or flight time falls within the restrictions so there will be a crew change.

I flew UA486 MCO-CLE yesterday (June 22) on a 737MAX9 and we leveled off at 27,000 feet and stayed there for the duration of the flight. Weather was clear, no bumps. Was curious why we weren't up higher in the 30's.

Today's UA486 (also a 737MAX9) is filed at 37,000 feet according to FlightAware.