The Fill and Flush deplaning method | Hacker News Reader

The Fill and Flush deplaning method

fillandflush.com

82 pointsvery_good_man184 comments

This is clever thinking, but we've been running airlines for so long now, I can't help but wonder if this has already been tried, and if there were issues with it. Potentical obstacles I can imagine off the top of my head:

- Will people even obey? What if half the people from the wrong side get up too? After a long tiring flight, will that anger people on the correct side and lead to fights? Having to show your ticket to prove you were in the right column to get off is not very customer-friendly

- What about families with children, couples, and groups in general? People want to stay together. It doesn't matter if this is rational or not, it's what people want to feel safe and not anxious

- Is it really even going to make much of a difference? In my experience, people are already mostly grabbing their bags quickly, simultaneously while the rows immediately ahead are starting to exit

And of course, while this can in theory save perhaps a couple minutes for domestic passengers with only a carry-on, even in theory it saves no time at all for anyone who still has to go through a crowded passport control or wait for checked baggage.

Getting off the plane is already fairly quick. Everyone wants to get going, usually the plane is empty in 5 minutes or less.

I think it would help with getting onto the plane. Filling the plane can easily take 20 minutes - which in a half hour turnaround is often the critical path.

The challenge here is you need to get people to enter the plane door in a very precise order. Just 10% of people ignoring instructions probably eliminates most/all of the benefits. Groups who don't want to sit apart or board the plane apart have to go either first or last.

Getting people to board in a certain order isn't particularly difficult. Southwest does it already, even if they only use it to... make sitting in a grounded plane a perk of checking in early? I'm actually not sure why they do it.

Thing is, you need people to board in a super precise order. Just two people swapped around in the line means someone can't get to their seat, delaying the whole boarding process.

That still would be much faster though than the current approach employed by most airlines which makes it more likely to create congestion in the aisle and minimizes how many people can load luggage and take their seat in parallel.

To get overhead luggage space before it fills up, or does SW not allow for that?

Southwest offers free checked bags so there is somewhat less demand for overhead bin space.

Lots of airlines will gate check your bag for free if the overheads are full, but the overheads are still in high demand because they give you one less errand leaving the destination airport.

I thought Southwest uses “open” seating, where passengers aren’t assigned a seat, but instead just take any unoccupied seat? If so, a perk of being earlier in the boarding order would be that you have a better chance of getting a seat you want, if you have any particular preferences.

> you have a better chance of getting a seat you want, if you have any particular preferences.

also have a better chance of not having to risk getting separated from your carry-on baggage because the plane's already full

Yes, they do, it's great. Being right at the very front of the line is a paid perk for singles, free for families with kids; being in the first main group after that is just a matter of checking in the night before.

Usually I find I can get a seat I don't hate unless I am running so late that I am in the latter half of the 'B' group or anywhere in the 'C' group.

This is why every southwest flight has 20 boomers in wheelchairs at the front of the line for preboard.

One time I was traveling with a blind girl who had a guide dog and the boomer patrol had occupied all the bulkhead space. They seemed to think she should sit with a German Shepherd in her lap. Needless to say I aggressively advocated and reminded the flight crew that FAA regulations entitle persons with guide dogs to a bulkhead seat. Let me tell you, we got some stink eyes from the displaced boomers who didn't want to have to walk an extra six feet to the potty.

> FAA regulations entitle persons with guide dogs to a bulkhead seat.

Google didn't find those regulations for me.

They don’t appear to be indexed well anymore. However here[1] is a fairly recent article mentioning the existence of the space rule. If I fly with a guide dog user again I’ll be sure to find the actual rule.

[1] https://upgradedpoints.com/travel/airlines/ultimate-guide-to...

> Filling the plane can easily take 20 minutes - which in a half hour turnaround is often the critical path

can you really reduce it that much, given that the plane needs to be refueled, cargo unloaded and reloaded, etc? like it may be the case that while it's inconvenient for passengers, the airline doesn't really care because it takes them a half hour to turn the plane around on the tarmac side anyway, so there's no benefit from reducing the passenger loading time.

passengers are frequently the critical path.

fuel and luggage crews can be quick. I've seen a luggage crew unload and reload a plane inside 8 minutes, including loading 2 airfreight containers.

There have been similar simulations for boarding airplanes. I wish I had never heard about them because now I get annoyed almost every time I fly.

As with de-boarding most time is wasted/spent by people standing in the aisle and waiting for someone who is putting their luggage in. The optimal solution has as many passengers loading their luggage in the overhead compartment in parallel as possible. The ideal way to do this would be that we first have passengers with window seats board with one person for each row. We should only use every other row to ensure people can maneuver. So we'd first board seats NA, N-2A, N-4A, etc. down to row 1 with N being the last row. Then NF, N-2F, N-4F etc. And then N-1A, N-3A and so on. Then we work our way through the middle seats and then aisle seats.

The current approach which commonly boards people starting from the front or back FORCES congestion and minimizes probability of two people reaching their seat at the same time and being able to put up their luggage in parallel.

Even if the approach I describe is broken because groups board together, it becomes at worst a random boarding order which is still much more efficient than the current nonsense.

The reason we cannot board more efficiently is because it's unintuitive, people don't like it and behave like wild animals in groups.

> Even if the approach I describe is broken because groups board together, it becomes at worst a random boarding order which is still much more efficient than the current nonsense.

I think it can quickly become worse than random.

Imagine you have the perfect sequence for max parallelism, but right in the middle is one 6 person family group who are going to take 10 minutes to get seated while they arrange toys and stuff for each child, blocking the aisle the whole time.

With the perfect sequence, this halts all boarding for those 10 mins, since people need to pass the blockage for the scheme to work. Whereas with random boarding, there will actually be many people who manage to get seated during those 10 mins, because there will be a bunch of people who, by chance, are seated between the door and the blockage and can get to their seats.

Unless the method is reactive, that family would always lead to the entire aisle being filled within seconds with waiting passengers who need to pass them unless the family is very far back in the plane.

> right in the middle is one 6 person family group who are going to take 10 minutes to get seated while they arrange toys and stuff for each child

such a group is slower, certainly.

they do not take 10 minutes.

No thanks. As someone who prefers aisle seats I don't want to get stuck boarding last to find that the overhead bins are already full.

Most flights I've taken in the last 5+ years use group boarding, which roughly approximates filling outside in (not front to back).

It only roughly approximates though because the first few groups are usually not outside-in (eg. first class, premium/rewards customers, veterans, families with small children).

I never understood the concept of boarding from the front. I would never want to be the first on a plane; regardless of status. And this means that every single person passing them will bump, cough, shuffle, past those that boarded first.

I guess it's just that people would feel bad going *last*? Psychology is weird - but powerful.

At least for me, the main benefit of boarding early is still having carry-on space. Last thing I wanna do is to have to check any luggage and then wait forever to retrieve it later.

On european airlines, luggage rarely overflows the overhead bins because you have to pay to use the overhead bins (often nearly the same as the cost of your seat on short cheap flights). The only storage you can use for free is the space under the seat.

That really changes the dynamics.

I always board as soon as my group is called. It ensures that I have space next to me for my overhead luggage, and I can start settling in, sometimes going to sleep. Plus, I'm already uncomfortable at the airport, what's a little more discomfort on the plane?

> The challenge here is you need to get people to enter the plane door in a very precise order.

Small amounts of money are often very motivating.

You could, for example, say that anyone can enter or leave the plane in any order they like. However, if they do so before their turn in the system, they don't get a $10 refund on their ticket. If they don't present their ticket, they are assumed to have gone early.

The question then, is whether the benefit would remain with proportional instead of total compliance, and whether the benefit outweighs the costs of enforcement.

My first thought is that there no way the boarding time is worth $10 per passenger to the airline, and no way they increase the cost $10 and don’t lose tickets to other people just using aggregate services like google flights and picking cheap options

Every plane I've been on in the last decade already sorts people by "boarding groups" which are relatively fine-grained. They won't let you onto the boarding ramp unless you're in the correct group, which they check by scanning your boarding pass. All they would have to do is make those boarding groups be based on your seating position instead of how much extra money you paid.

Exactly. This proposal entirely ignores human nature, and the author has obviously not done any research into the problem beyond being annoyed while waiting to exit an aircraft.

There's this 2015 article on doing essentially what he/she is suggesting: https://www.vox.com/2014/7/8/5877863/it-takes-forever-to-get...

There's a paper on solving the problem by assigning passengers to seats so that their luggage is evenly spread throughout the overhead bins: https://www.sciencedirect.com/science/article/pii/S096969971...

There's a paper here on other methods tried, including creating "pre boarding" areas for passengers: https://www.researchgate.net/publication/269466040_Speeding_...

The first step in any scientific endeavor should always be a literature search.. see what's been tried, and what worked and what didn't.

> Will people even obey?

One solution might be to have lights that light up when it's time for your column to deplane.

A more evil solution would be to use physical barriers that only open when it's a given column's turn. Maybe replace the seatbelts with rollercoaster-style restraints for extra fun.

> What about families with children, couples, and groups in general?

Have them deplane either first or last. The page seems to suggest that waiting for the next "wave" ain't a huge deal, so having groups wait until their last column is ready to go (or worst case, until all individuals have deplaned) could probably work.

> Is it really even going to make much of a difference?

Maybe not in isolation, but maybe the aggregate effects (e.g. more flights per day) would justify it?

Yeah, I read analyses like this article and just think "this person doesn't realize that they don't think/act like most people".

Most people flying are not traveling alone. It's not just the oft quoted "families with small children". What about couples/friends/colleagues. People traveling together largely sit in the same rows, not the same columns, and they want to exit together.

These kind of analyses (especially the "if everyone saved 13 seconds we'd size the equivalent of 20 lives!" part) always make me a bit said because, in a lot of cases, it's clear the author understands math but not humans.

I've considered the "group" issue at length and do not consider it a major issue. People like us are obligated to improve the world for the less enlightened.

In a world where we can’t convince people to wash their hands (among other more controversial public health asks that shall remain nameless to prevent ideological thread derailment) I don’t think we can convince people to not descend into chaos when asked to do something like this. It’s a great idea for efficient pipelining, but humans view the emptying of each row in order as more fair and common sense. It doesn’t require coordination beyond the people within rows and is resilient to people bucking the protocol.

I wonder how rapidly this column wise deplaning breaks down in the face of random compliance and confusion.

I guess families with young kids that would have to leave the kid in the window aisle, distressed and upset while the only people they know are leaving them in a vessel with people they don't know, are just not "enlightened" enough.

I implore you to consider the group issue in more detail, and perhaps with a touch of human empathy this time.

You're allowed to wait for later flushes, and to trade your position for a nearby neighbor's! Families would be absolutely fine in this system.

> People like us are obligated to improve the world for the less enlightened.

This really says everything you need to know about this "analysis".

The notion of 3 travelers on window, center, and aisle being OK to wait through FIVE flushes (aisle, opposite aisle, center, opposite center, window) to reconnect -- and the notion this is "enlightened" -- I can't.

The notion that ALL sets of 2+ travelers now have to wait at the end of the gangway just inside the terminal, the disaster that would create at the gate, is just kicking the can off the plane in a way that doesn't actually help the next passengers get on any sooner. The gate -- and all gates -- would be a disaster.

The author has definitely thought about those concerns, since they're mentioned on the linked page. I think it's just a neat simulation, it's not necessarily a comment on someone's ability to empathize with other human beings.

The author thought about those concerns, but somehow doesn't think they're a big deal, as opposed to making the entire thing completely infeasible.

Another commenter put it brilliantly: "My perpetual motion machine works brilliantly, just have that 'unresolved issue' of the second law of thermodynamics".

This would defeat the economics of class seats, which is way more important for the airline than getting people out the aircraft, and it does not address the obvious issue with carry on luggage, which is an even bigger problem in single aisle aircrafts.

And more obviously, the level of coordination required to make it work is just not worth it. Families flying together, babies, people with disabilities, etc., none are considered in the model.

-First Class can keep getting off first, you still get the benefits if you apply this to Coach

-Groups can wait for later "Flush" es - there is flexibility since I think you can fit a little more than one person in the aisle per row.

These days coach has multiple tiers and they're not necessarily in a uniform location. Whereas first class is always in the front

> First Class can keep getting off first, you still get the benefits if you apply this to Coach

Domestic flights on single aisle aircrafts, have several classes (first, extra, etc.), with different price ranges. Even emergency exit seats come with some attached benefits, like priority boarding. Good luck telling customers that they paid extra for an emergency window seat, but have to wait until more than half of the plane have de-boarded to exit.

> Good luck telling customers that they paid extra for an emergency window seat, but have to wait until more than half of the plane have de-boarded to exit.

That's exactly what already happens (at least in Europe), you don't get priority to de-board if you bought seats with extra leg room on the emergency exits, you have to wait.

The point here is that someone on a window seat would have to wait until most of the passengers have left, even if they have paid extra.

Why is "people won't listen" a real argument here? They'll do what they're told or they'll get banned from flying on that airline, and possibly pay up to $25k, as it's a violation of 49 U.S.C. § 46504 to interfere with a member of the airline crew.

Next time you're on a flight, listen for the number of people who remove their seatbelts before the seatbelt light goes off, after a crew member specifically says not to do this

I haven't seen any of them fined 25k. Proportionality matters, and getting off the plane as fast as (in your mind) possible isn't going to be realistically enforced.

Removing one’s seatbelt and leaving one’s aisle are completely different behaviors.

It really is absurd that people can’t even listen to such a simple rule. What is so hard about it. They really should be giving out these fines for misbehaviour.

This also reminds me of an article I once read in an in-flight magazine about this. It was saying how an airplane’s brakes work really really well, not only at 350km/h when landing, but also at 50km/h when taxiing to gate. It described an incident where during taxiing to gate after landing, somehow some animal managed to jump right in front of the plane forcing the pilot to apply max break, causing a passenger who was handling the overhead bin to die from the injuries.

Actually, just found a picture I took of the article, so here’s the original text. I always think of it when people stand up before the seatbelt sign is off.

> … But ignoring these rules can have serious conseances. For instance: Do you really remain seated until the plane comes to a complete standstill? German travel journalist Heige Timmerberg likes to tell the story of the dog that ran across the runway in Casablanca, forcing the pilot to slam on the brakes. Brakes that work well at 350 km/h, work well at 50, too - and one of the passengers who had just emptied the overhead bin "flew from row 26 to the lavatory behind the cockpit, and was dead." > "We don't joke about security," says Fabienne Regilt, member of the lufthansa team.

As a 6' person, if I can't explicitly reserve an exit or aisle seat, I am not flying with your company, because I prefer to not get thrombosis. And I'm sure as hell not going to rely on the willingness of my cofliers to be reasonable about letting me queue so that I end up with the seat I need, while my partner gets the seat next to me.

The more obvious solution is to also use the rear door in addition to the front. Airlines could then charge a premium for those seats as well. No big coordination effort is needed, but it would require some new jetways or some terminal reconfiguration. Other countries do this frequently with no major problems.

> The more obvious solution is to also use the rear door in addition to the front.

Now you have to play with the airport itself. Most wouldn't have enough bridges to lend two per gate.

Isn't that common in the US? In Europe it's quite usual to have the front door on the jetway for the first half of seats, and a staircase for boarding the last half through the rear door. Thought it was normal procedure, it varies a bit per country and airport here but is common enough, I'd say more than 50% of my flights are configured that way.

> In Europe it's quite usual to have the front door on the jetway for the first half of seats, and a staircase for boarding the last half through the rear door.

This is definitely not usual.

Admittedly, I haven't been to all airports across the US or Europe, but I have been to quite a few, and have yet to see people boarding from the front and back. Closest perhaps was a double bridge used on an Emirates A380.

I just got a flight Stockholm-Prague a week ago, we boarded from both doors. In May I went Stockholm-Zürich, boarded from both doors, then Zürich-Lisbon, same.

Last time I flew to Berlin with EasyJet it also boarded from both doors, now that I'm listing it I can only remember a flight from Oslo-Stockholm with Norwegian where the boarding was done only through the front door. Most of the flights I've taken the past 2 years have boarded from both entrances, I feel it's quite usual.

I haven't been to any of those airports, except for Lisbon. Didn't see any front and back boarding in there. Neither in BCN, MAD, LHR, LGW, IST, or AMS. I have boarded and de-boarded from the back (but not from the front) in a handful of smaller Spanish airports, though.

In the US, I would say that it is not usual at all, or I have been to the wrong airports (IAD, DFW, AUS, IAH, SFO, LAX, JFK, LGA, CLT, ORD). I haven't seen this either in Asia.

Perhaps this is highly airport dependent? Still, I would think that this is far from common.

But did the front use the jetway and the back stairs? I've seen stairs on both, but have never seen this mix at any airport anywhere.

Yes, the front used the jetway and the jetway has a staircase to access the tarmac, people walk from there to the back of the plane and up the stairs.

I'm very surprised that so many people are telling me this is uncommon, I've been through this setup countless times.

Interesting! At what airports have you seen this?

I think that all flights in Europe I've taken with low cost airlines had both front and back entries (and exits). My memory good back to maybe 10 years and 4-10 flights a year.

I used to fly much, much more but I do not remember that far in the past.

It's pretty uncommon in the U.S. to board a plane from stairs on the tarmac. There's almost always a gate. I haven't seen the "gate for the front, stairs for the back" loading style in Europe, but I've seen two sets of stairs pretty often. If the goal is to save passenger time and inconvenience, having to take a bus out to a hard stand is definitely not worth the payoff of being able to load from both ends.

Loading and unloading from both ends is a lot faster though. United actually had a double ended gate that they were trying out years ago in Denver, which is the best of both worlds and saves a ton of time loading and unloading. It's this really long cantilever thing over the wing to reach the rear entrance. Unfortunately something broke on it one time and the jet bridge fell onto the wing, damaging the airplane, and they gave up on it.

You shouldn't need a bus because the plane is at the gate. Stairs might be an issue for some but anyone that does not want to go down then back up stairs can wait and go out the front through the jetway.

As others have pointed out, this method works great in many other countries.

The tarmac at an airport is dangerous, noisy place. You don't want people wandering off.

Right but there are ways to handle this like collapsible barriers that would be quick to put in place. If people prefer to go through the jetway they always can and simply stay seated.

This is proven out already in other countries, the ones that want to leave through the jetway stay seated and still get out faster because even if they are near the back most people around them leave through the rear so they make it out the forward jetway much quicker.

Jetways for boarding and deboarding is most common in the US. A near requirement because of the Americans with Disabilities Act, which requires reasonable accommodations for people with disabilities, and a jetway is deemed reasonable for people who can't do stairs.

Some airports will revert to passenger stairways when there's more planes to put passengers on, and the weather permits. Airports that often do that, may also sometimes use passenger stairways to accelerate deboarding, but passengers aren't very good at doing that; and when overhead bin storage is tight, you may have placed your items in a bin too far forward to retrieve it while passenger motion is towards aft stairs. I can't recall seeing boarding from the front and aft simultaneously.

Very very occasionally, I've seen or heard of airports set up to attach multiple jetbridges to a single aircraft, but that's going to be pretty complex geometry because distance between the front door and the aft door on different planes varies widely.

The problem is that families sit in rows together, not usually in columns. And in busy airports it's not very ideal to get split up from your travel partners, especially if they are young, old, need assistance, etc.

I believe the response to this objection is to just have the groups wait for later "flush"es / make "trades" with strangers who would otherwise exit in later waves.

That's a lot of extra coordination to add to a method that already depends on an awful lot of coordination.

Second this point, especially when flying with young children. But I imagine that slight modifications could be made to get a hybrid approach.

Have y'all flown recently, or ever??? I feel it's hard enough these days to get people on planes to be fully clothed, semi-sober, and to refrain from violence. And somehow we're all going to coordinate perfectly to get this complicated choreography to work?

This is what I came to say. The proposal is obviously written by someone who is single and travels alone.

> Unresolved Issues:

> How to accommodate the elderly, people with children, and groups.

Guys, you have to read the article at least. It's stated in the "further discussion" section so at least add something more than just repeating the topic.

Or, I suppose, rewritten in the vernacular of this site:

"This comment is obviously written by someone who didn't read the proposal properly".

Your judgement is wrong. I had read that. I retain my opinion of the article. They ignore the elderly, families, and groups. Which are a large portion of travelers. Plus they acknowledge that they are creating passenger conflicts, and don't address that.

Coming up with a better proposal than this is trivial. Here goes.

During flight, lock the overhead bins. When deplaneing, those without overhead luggage go first, from first to last row as now. This makes sense because they generally walk faster because they have less stuff. Those with overhead luggage have to wait for the steward or stewardess to unlock the overhead bins following the fast group, and then exit from last row to first. Therefore those who are slow to get things out of bins, do not slow others. Those needing assistance wait until the very end, as now.

Getting stuff out of bins is the gating factor here. And so there is no passenger conflict about the fast people leaving first, because the others are waiting on the bins being unlocked, then for people behind them to pass. And groups get to leave together.

There you go. A faster approach than now. With fewer problems.

While I reject your condescending tone, locking the overheads is possibly a good idea but requires major equipment upgrades.

I do not believe locking mechanisms in the overhead compartments are currently installed.

Controls to instantly lock/unlock such systems remotely by one attendant, thousands of times, reliably, is yet another challenge. Better to engineer a solution that requires no new equipment.

When I compare tones, mine seems far less condescending than the person I was responding to.

Engineering a solution that creates passenger conflict is not a good idea. I'd rather wait for slow people, than be around a loud argument at the end of a flight. I get enough stress already from hours of being cramped on a flight, I don't want more.

Also you are adding entirely unnecessary requirements to my solution. There is no need for the unlocking to be instant. Just to be doable one by one by someone going around the pace of people dragging luggage. The technology used for security tags in clothing stores would be more than adequate.

That said, I'm not seriously advocating for my solution. I'm just saying that it takes no more than 30 seconds to come up with something better than the one the blog post was about.

Wut?? So if I'm in a window seat, and the folks in the middle and aisle seats have carry-ons, I'm supposed to crawl over them, or have them block the aisle while we somehow shuffle past them? Do you understand the size of the average American?

I live in the USA, and am 6' 3". So yes, I understand the size of the average American.

I've never had a problem going to the bathroom. People get up, sit down. And there is plenty of time to do this while waiting for the line to start moving.

Also, remember that this is not a proposal I'm seriously arguing for. Merely showing how easy it is to come up with a better proposal than the one made.

"This article is obviously written by someone who doesn't understand the problem space, or human behavior."

> Unresolved Issues:

> Second Law Of Thermodynamics

Other than a few details to work out, my perpetual motion machine is going to revolutionize aviation.

I mean, yeah. A similar sort of structure is how the Alcubierre metric works. It requires negative energy normal to the manifolds involved. If he described that and everyone replied "You need negative energy" that would be kinda dumb.

Seems great in princinple, but I'm not sure this would work when coming up against human behaviour. It's as much as the stewards can do to stop some people charging down the aisle the minute the plane comes to a standstill, let alone communicating something this nuanced to everyone so they understand.

It also means that families who are travelling together would need to deplane separately, which can screw up things in terms of helping each other with bags, and also wouldn't work with families who have multiple kids of an age where they need to walk with their parents. It feels like the kind of fragile system where you'd end up with so many exceptions that it becomes potentially even more messy as you'd need to communicate those exceptions and people would need to understand them.

That's probably why OP said it's open for discussion. But yeah herding (isn't the correct term flight attendants and not stewards?) the passengers would be difficult.

Perhaps the procedure should be, if everyone in your group is holding all their belongings - either in the aisle or standing in the footspace of an aisle seat (so rows C and D in a 3-3 configuration), then they can join the deplaning wave. But if you're standing in the aisle but one from your group is still crouched in a window seat and will need to grab their bag, and you don't want to abandon them, then you don't occupy the aisle go back to your (presumably aisle-) seat and wait for the next wave/go into an empty row so the crouched passenger can stand in row C/D, and wait for the wave to finish so they can grab their bag.

> Unresolved Issues:

> How to educate passengers

The author vastly overestimates peoples willingness to do literally anything that benefits the group rather than themselves.

It does not matter if every single person goes through a six week course on why this system is better: at least 20% will still ignore it to get themselves off the plane sooner. "I have a connection! I'm in a hurry! My Mom is waiting for me!".

You want a better system? Design one that works best when everyone is greedy and maximizing their own benefit.

This is why I think it's important to emphasize the raw number of lives saved. There are winners and losers in both systems, so important to focus on the lives saved by adopting something now. We'd need strong social penalties for any deviant action that blocks the aisle.

Better off watching CGP Grey's video "The Better Boarding Method Airlines Won't Use" which has more discussion of the topic, more simulations, and puts forward better methods that are either faster or allow families to remain grouped.

https://www.youtube.com/watch?v=oAHbLRjF0vo

This is basically https://arxiv.org/abs/0802.0733 but differs to the paper in that it doesn't consider: alternating odd-and-even row disembarkment, which would give passengers more aisle space to potentially speed-up luggage handling.

I recommend not reading it. It made me a less happy traveller.

The simulation of the status quo makes the assumption that aisle seat passengers wait until the row ahead of them is clear before collecting their luggage, nobody ever manages to squeeze past someone collecting their luggage, nobody in a middle or window seat is ever able to retrieve or be given their luggage until the aisle opposite them is completely clear, nobody ever walks past someone in an aisle or middle seat that hasn't collected their luggage yet etc...

Suffice to say, this is not my experience of boarding and leaving aircraft.

The simulation assumes that ONE person in the status quo has a 0 second assemble belongings step, and just waits "minBuffer" time - so in the simulation on average this is 2 second delay rather than 5:

https://github.com/josephecombs/fill-flush/blob/fc0fa73b5879...

I have been on flights where passengers are still finding their seats and arguing about overhead baggage locations while the plane is on the runway - and now you have the air traffic controllers moaning at the pilots (why aren't you taking off! You only have a 120 second slot!), the pilots moaning at the cabin crew, the cabin crew moaning at that one family who just can't decide what order to sit down, and dad of the family moaning at the daughter to sit next to her brother and stop complaining.

Ryanair even seems to have a way to communicate this. "cabin secure" means everyone is following the rules. "cabin secure, kinda" means we're gonna break the rules and hope everyone sits down before takeoff.

Airlines would bastardize this by doing it by class then column, as you can't have steerage riff raff get off before double platinum diamond medallion clearly superior than you first class.

In that model, would it faster or slower for someone in the middle of end of the plane?

When I was in Colombia, the thing that jarred me the most about flying was that people waited for their turn to get out of their seats. It was a block system (e.g., rows 1-5, then 6-10, etc.) Honestly, it was refreshing compared to everyone jumping out of their seats and then trying to bolt to the front of the plane to get off as fast as possible.

The big problem is getting bags out of the overheads. So I think the best way to get people off planes quickly would be to prevent as many people as possible from carrying on luggage.

There are 2 reasons people use carry-ons rather than checked bags. First, because its cheaper for people w/o status, and second because they're worried about the airline loosing their luggage, and/or they don't want to wait for their bags.

To negate the first reason for carry-ons using a carrot + stick approach, I'd offer 2 free checked bags to everyone regardless of status, along with charging $100 or more per carry-on.

The second reason might be harder. The airlines would need to re-negotiate deals with their credit card company partners (suddenly the free checked back with the Delta Amex plat. card doesn't mean anything) and change their frequent flier programs, and they'd need to get better at bag handling in general.

There's also option three - fear of damage or theft. Short of a guarantee that my baggage will be handled by a generously paid individual who will treat it with the tenderness of a lover, I'd rather take care of my laptop, camera + lens, etc. myself.

Or you could have a rule that people without overhead baggage get to deplane before everyone else.

I like this. Just lock the overheads for the first few minutes after the boarding door opens..

I wish there was an airline simulator game.

"Checked luggage is lost luggage" has been my mantra for over a decade. I never ever ever check a bag unless a flight attendant requires me to. Obviously everyone's needs are different, but I'm fine with a carry-on for any length of trip. After 1.5-2 weeks I may need to do laundry, but that's fine.

There are probably solutions to the problem of it taking too long for people to pull their bags from the overhead bins.

This is slower than the current system because column 2 can not stand up (or prepare to exit) until others have completely exited.

Also you cannot exit with the people you sit next too (like your toddler who will have to make their own way off?).

And that's assuming anyone actually wants to minimise average time. Airlines don't. Neither do most passengers.

People don't need to stay together when they know there's nowhere to go. The question is whether airlines could communicate the value of this new method to induce compliance and not have to use some enforcement mechanism, or some other forms of carrots and sticks

This is a fine simulation, and, as described, it does not account for overhead baggage handling, and as mentioned in other comments: families traveling together.

If you have ever taken a commercial flight, you have seen it: the individual that needs two people to team up (or one highly capable one) and lift up or down their 40-50 lbs (~20 kg) roller from the overhead. Half the time, their help is in their party, but it slows things down.

I would estimate that this happens at least once every 4 rows on a fully occupied 6 seat wide aircraft.

Given this, forbidding passengers to bring carry ons aboard that they can't overhead lift themselves would be the only way to speed things up regardless of boarding/deboarding strategy.

Is that practical? Probably not.

Just stop charging for checked bags and you resolve a significant percentage of the problem.

Many people -- myself included -- will not check bags regardless. I don't want to risk my luggage getting lost or damaged, and I don't want to stand around for 15-30 minutes waiting at baggage claim after my flight.

After a return flight, I'm usually at home by the time my bags would start coming out if I checked them.

Exactly - they should charge for carryon bags and give checked for free, because apparently the desire is for carryon.

Every once in a while these ideas for quicker, more efficient boarding of commercial passenger flights come around, and every time I look at them and think how well they work if you assume the passengers are perfectly spherical cattle.

There’s rumors of a Boeing engineer who went nuts and began designing systems for sedating the passengers beforehand and shipping them all in the prone position.

An obvious easy improvement would be to move the doors to just above or before the wings, so you could drain from two sides at once.

As others mentioned this only works if we assume no seat classes and people not flying in groups.

First class, golden carpet diamond supreme customers won't tolerate waiting for someone from the back of the plane to exit. Their head would explode probably and they'll vow to never fly that airline.

But overall the problem is that people fly in groups and they like to sit together. Sending the kid out while the parent waits for the next column to deplane will never happen. Should the people in groups wait then, but a good part of the plane will just stay waiting and it's back to the existing algorithm anyway.

I love this because it's exactly the thing that an enraged engineer who is stuck in the last row waiting to get off a plane would create -- just a little naive given airline incentives, couples, families and the limits of human patience :)

I would much rather if all planes had a second staircase at the back, jet bridges aren't needed. That, or let people check luggage for free again so they don't need to manhandle carry-ons.

My guess is that airports also prefer a slower release of passengers -- it means customs lines and bathrooms aren't immediately saturated.

Let's fix all those other flow bottlenecks too :)

Is there actually a reason we cannot have two jet bridges? I have a bias for jet bridges because they generally seem to lead straight to the gate whereas at airports that use stairs it seems like I typically have to get on some bus (FRA, KEF, LAX) first or walk very far (PDX, SEATEC), since stairs are only at the furthest out gates.

It’s hard to get to the rear doors without making the whole thing take up more space (getting over, around, or under the wings is the problem).

I've never seen a plane where there's exactly one person in the entire aisle and everyone else waits. Never. So yeah, this is way better than a method that doesn't happen.

This happens constantly during deplaning? I think this is a little quirk of how the animation is rendering. There are "little people" standing in the rows behind whoever is currently gathering belongings.

Yes, but no one waits for the guy in front of them to completely exit the plan before they walk down the aisle. It's always the entire line moves and people are always getting in the line. Never does row 12 wait for row 12 to be totally off the plane before standing and getting in the aisle. Row 13 is about 6 inches behind row 12 as they all walk out of the airplane. The only difference in real life between this proposed optimal is that in this design, you intentionally call out aisle, middle, window, while in the real world all the aisle people stand up automatically without being told. I'm saying his plan is already what's in the world just less planned and rigorous. But I've never been on a full plane where the aisle is empty as much as in the straw man simulation in this one.

So what do you think the real number of people who can fit in the aisle per row? 1.2? 1.5? 2?

Based on every single airplane I've ever seen or been on, with bags I'd say about 0.8 times an many people as there are rows, plus about 4 people between the front row and the exit door. On a Southwest 737 with 24 rows, that works out to about 23 people.

I've never seen deplaning be the hold up, it's boarding that takes forever. But getting people to follow complicated high-speed boarding plans is like herding cats.

Honestly I wonder how much time could be saved on an ultra low cost airline by just permanently locking the above head compartments that people have to stand in the aisle to use. That seems like the biggest hassle.

You could even up-charge for above head storage, but only allow seats at the tail of the plane to choose that upgrade. They board first, and they deplane last, ideally holding up no one.

This sounds like hell but hey… if it saves a few bucks a seat on a really short flight because they can deplane in 5 minutes… I’d be for it.

I don't think those are structural. So I think you could even remove vast majority of them entirely. Saving in weight thus in fuel.

I've often wondered whether they could "containerize" passengers by having the seating as a whole remove from the plane. People then have all the time in the world to get seated outbound, and additional space to deplane at their own speed inbound. You could even come up with a system for putting luggage directly under their seats obviating the need to collect it separately. (It would of course be a massive redesign of planes and airports, so probably not an easy starter).

So passengers crowd into narrow tubes a bit earlier, and then the narrow tubes are winched into the aircraft with the sort of painstaking precision that takes several minutes? Even assuming airframes could be redesigned to make this possible [at zero cost, without implications for structural integrity or operational complexity of the resulting aircraft] I'm not sure who benefits here?

Not sure if it needs to be a tube. Maybe the seats could be on a rail that slides into the airplane. Having to move the nose and tail of the plane up for this also brings us closer to my dream of flushing the entire airplane with Clorox between flights.

The rails would be fun, I guess

Has this guy ever been on any actual planes? His "Status Quo" model is completely unlike any of the planes I've ever been on.

It's easy to improve over a fake strawman

I assume that the author has been on planes enough to think about this and make a website with a simulation.

It seems fairly realistic to me. People in rows toward the front step into the aisle as soon as possible to gather their carry-ons. This blocks everyone rearward that already has their belongings and is in the aisle from deplaning.

Unloaders will yield to a non-zero average of waiting passengers. Unloading passengers in fore rows can predict, time, and exploit gaps in passing back row passengers such that they can unload without causing slowdown (in this way full and flush in non-optimal).

Its really not that realistic.

These little real world improvements are available in both systems and do not impact the overall conclusion.

Exploiting gaps and streaming out passengers into the isle is antithetical to fill and flush. It can't be added or it changes the entire concept.

The simulation currently encodes an average 2 second gap between passengers in the deplaning aisle - in theory you could shoot in when a passenger with a longer minbuffer is near you. This can be done so long as it does not cause accordion-style congestion in the aisle.

Yes you could, and that would be closer to real life but it would fly in the face of the proposed, flight attendant orchestrated flush.

What's the point? I'm going to have to wait for my checked bags anyway. Passengers who really care about deplaning quickly should just select seats near the front.

I have calculated this would save between 50 and 150 human life-equivalents of time per year. You can see this calculation if you scroll to the bottom of the simulation page.

Sure, but it doesn’t add up to much useful time per person… Aggregate time saving across large numbers of people just seems like a fairly useless measure in general. To take it to an extreme, if you saved ten seconds in something everybody in the world does once or twice, you’d have saved a very large number of person years in aggregate but made basically no meaningful improvement to any individual’s life…

I’d think airlines would really want to put pax at the front that have tight connections (before or after). Unsure if any think this far ahead though.

But I also think they should put healthy 25 year olds in the emergency exit row for… emergencies, but they’d rather sell those seats to someone that’s often the poorest candidate to execute in an emergency.

Since planes rarely fall directly out of the sky, I wonder if there’s documented cases of “oh it’s an actual emergency” and people swapping seats.

You don't know that up front, e.g. if your plane is late and you need to hurry to a connecting flight.

Many people don't check baggage at all. This avoids extra fees, avoids waiting for checked baggage, and eliminates the possibility of lost baggage (assuming they don't make you gate check your carry on).

not everyone have checked bags. we only check our bags when going on long vacations, on majority of our flights we have only small bags.

For the airline, quicker deplaning means quicker turnaround, or a chance to give the plane a better clean-up before the next load of passenger shows up.

I almost never check a bag, everything I need fits in a ~35L duffel bag and 20L backpack. If I need prohibited or oversized tools or toys I ship it to my destination by UPS.

I also end up near the back of the plane all the time, because those are the available seats that don't have a higher price tag.

The delay is just a waste, but unfortunately the airlines aren't incentivized to make boarding or deplaning quick, they're trying to upcharge for more expensive seats. All the engineers are sitting at the gate for 15 minutes wondering why everyone's in a rush and paying extra to get "priority boarding" onto a cramped plane, then at the end of the flight, they're sitting in the back of the plane wondering why it takes 15 minutes for everyone to get off the plane, and how this wasteful process could be made more efficient.

Works well when done with robots.

Now simulate it with humans who really want to get off that flying toilet that has been their home for 12 hours. No amount of education will suffice.

Unfortunately, no solution that relies on this level of coordination will ever work. We cannot even get people to not block the corridor randomly when boarding or offboarding, enforcing a routine like this is not going to happen.

Sorry for being negative, I like that you came up with something clever. I've seen some similar attempts to make boarding more efficient. I just fly way too frequently and I think the world is not ready for this yet.

You could try to incentivize it - give free checked bags to those with window seats, but charge them for carry ons, and give carry ons for free to the aisle seats.

This is great. This is mentioned in the discussion topics section ("modeling randomness in gathering belongings"). But I wonder what the distribution of baggage-gathering time looks like? I'd guess pretty positively skewed, i.e. most people are pretty quick but then a few people take a long time or a really long time. The speed of the flush stage of a particular wave is capped at the slowest person in that wave.

Airlines added baggage fees to capture more revenue. Passengers started bringing more carry-on luggage as a result, filling up the overhead bins. It now takes longer to gather ultra-heavy, overlarge carry-ons from the bins to exit the plane, affecting exit times.

Stop nickel-and-diming for luggage and focus on efficiency gains like gate-checked small luggage. Add front and back exits to every gate ramp to improve boarding and unboarding.

"How First Class is handled."

That's by far the easiest issue to handle: don't change a thing... they get off first exactly how they do now.

Unloading is pretty fast. Loading is the slow part.

However efficient loading doesn't make passengers happy.

Priority boarding is worth an extra fee from some passengers and adds several minutes to boarding time.

https://youtu.be/oAHbLRjF0vo for a bit more about various options and the reason it is all moot.

There is a great video from CGP Grey about the similar problem of boarding an airplane: https://youtu.be/oAHbLRjF0vo

Unfortunately, having flown many times, I just don't see humans ever being able to self organize to this degree, especially at the end of a flight!

Idea: deplane by row. Each row leaves when a light in that row turns on. An algorithm decides when to turn them on based on several factors: keeping large groups together, expected speed of deplaning (eg. elderly may be slower), current occupancy of the aisle. Advantage: should be very fast, easy to follow, groups stay together.

The simulation is overly simplistic.

If someone in row 3 finishes their bags, the other people in row 3 don’t always hold up the line for the rest of the plane.

- some people prefer to sit and wait

- some people let others through before blocking the aisle

Anyway, I think “let some people through before you get your bags” is also way easier for people to understand.

CGP Grey did a great YouTube video on this several years ago, and why airlines won't use it: https://youtu.be/oAHbLRjF0vo

Note that this is from a boarding, not deplaning viewpoint, but the concepts are similar.

Hard to see such a complex sequence working. Maybe there could be a "Aisle passengers without carry on baggage (just a purse perhaps)" exit first call. Then follow with the normal row by row exit. This would allow people who want a fast exit to achieve one.

It is absurd to imagine that the passenger in the first row window seat gives a flying fuck about the disembarking time of the last passenger, and then build a model on that absurdity and present it as a serious suggestion.

I think in practice, if 1F could sneak out without blocking the aisle, it doesn't matter. The true important thing is that the aisle not be blocked. The aisle space is the limited resource. There are even more "lassiez-faire" versions of this simulation that could somehow try to model "unregimented" standing. Might be worth doing.

Ignores idea that overhead bags sometimes end up behind the row. Even if you didn't put it there, stewards have the authority to move them around, and often will to accommodate other bags.

Just eliminate baggage fees. Deplaning is significantly faster when there’s no disincentive for checked baggage.

In all of my flights I've seen that people allow the row in front of them to deplane first. It's just courtesy I've seen. Is this similar to "fill and flush"?

That is modeled as "status quo" - this unfortunately leads to waste of the scarce aisle real estate, a resource that is better used in "Fill & Flush."

Unfortunately this is just about as useful as economic theories that rely on perfectly rational consumers. Good on paper, worthless in the face of human nature.

There's a great deal of imperfection and slack baked into this simulation. I invite you to read the source code. In it you'll see that I explicitly afford for slack in the walk and belongings-gathering steps.

That's a good start. You also need bake in the fact that 20% of the people will ignore this system and attempt to exit out of order because they're in a rush / they are "important" / they don't give a flip, which will then have a domino effect.

Is getting off passengers a bottleneck in the whole thing?

Yes, for anyone concerned about missing a subsequent connecting flight.

If you’re worried about that tell the stewardess before your descent begins, they can prioritize you, up to and including moving you to first class just before landing.

Flight connections are not synchronized at that time resolution.

If they care about it then allocating seats closer to exit for people with connected flights would make more difference.

It will never work. Deplaning always uses the greedy algorithm because the people in the front will not let the people in the back off before them.

Suppose someone doesn’t rise and leave in formation? Suppose the rich people in row 1 on the window decide they aren’t waiting?

Easier to herd cats.

I have "invented" a system that I believe reduces aircraft deplaning time by ~50%

source code at: www.github.com/josephecombs/fill-flush

Reducing passenger loading and unloading times (also called "Turn Times" in the industry) is a surprisingly hard problem that has been and continues to be heavily studied.

Field studies watching actual passengers loading actual planes (as opposed to computer simulations of theoretical "people" loading theoretical planes) frequently show the fastest loading when passengers are lined up randomly, ahead of any of the more seemingly "intelligent" approaches that work great in computer simulations. If the "best practice" algorithms can't even beat the random algorithm in a field study, that's a sign this is a much harder and much messier problem than it appears to be.

Just about any google search, like "airplane passenger loading research", will return more than a dozen theoretical and field studies on the first page of hits, including:

[0]The Role of Computer Simulation in Reducing Airplane Turn Time, https://www.boeing.com/commercial/aeromagazine/aero_01/texto...

[1]A Simulation Study Regarding Different Aircraft Boarding Strategies, https://upcommons.upc.edu/bitstream/handle/2117/19651/145014...

[2]Analysis of Airplane Boarding Times, https://www.researchgate.net/publication/220244330_Analysis_...

[3]Efficient Aircraft Boarding Strategies, https://labs.engineering.asu.edu/ilpil/research/efficient-ai...

[4]Passengers boarding airplanes: we’re doing it wrong, https://theconversation.com/passengers-boarding-airplanes-we...

[5]The Best Way to Board a Plane, https://phys.org/news/2008-02-board-plane.html

[6]Loading an Airliner Is Rocket Science, https://www.nytimes.com/2006/11/14/business/loading-an-airli...

[7]Comparative Study of Aircraft Boarding Strategies Using Cellular Discrete Event Simulation, https://www.mdpi.com/2226-4310/4/4/57

[8]Intelligent Boarding Modelling and Evaluation: A Simulation-Based Approach, https://www.hindawi.com/journals/jat/2021/9973336/

[9]Improving airplane boarding boarding time: a review, a field study and an experiment with a new way of hand luggage stowing, https://commons.erau.edu/cgi/viewcontent.cgi?article=1200&co...

[10]A Comparison of Algorithms That Estimate the Effectiveness of Commercial Airline Boarding Strategies, https://commons.erau.edu/cgi/viewcontent.cgi?article=1072&co...

[11]The Mathematics of Aircraft Boardingg, https://www.maa.org/external_archive/devlin/devlin_05_06.htm...

(among many others)

I have seen many of these results and did not find a lot on the very specific issue of DE-planing. Most of this stuff discusses boarding.

It's incredibly difficult to get people to deplane according to any particular planned method, at least in the US.

This is why I suspect there to be an even more lassiez faire approach available:

1. ANYONE fills the aisle

2. Entire aisle is flushed (aisle obstructors are somehow severely punished)

3. repeat until done

This would probably be even faster than what I propose but is a lot harder to model.

Seems like it ignores people traveling with others (like children and disabled folks) who need assistance.

No it doesn't. This objection is addressed directly multiple times in the repo and in the explanation.

No the objection isn't addressed, it is waved away.

What if your bag is far from your seat?

That feels like an American thing, I fly in Europe and my luggage is almost always above my head or across the aisle. Do American fliers put it in the first space they see in the overhead luggage?

In my American experience, flights these days are almost always completely full, and almost every passenger is bringing both an under-seat and overhead-bin carry-on item.

The last 10% or so of boarders are often left with no overhead storage near their seats. The last 5% or so of boarders are often left with no overhead storage available at all.

"Put it in the first space you see" is often explicitly an instruction that the cabin crew gives to boarders as overhead space starts dwindling. Passengers aren't doing it out of preference.

EasyJet (ie, in Europe) is constantly packed, and people who board later frequently need to find space elsewhere for their bag, because the space near them has already been taken.

"great" if you travel with kids/family.

you actually expect people to abide by this?

people default to the "f you, I've got mine" mentality so there's no way this will work.

competitive de-planing would be an amazing sport

It would be cool to see how fast a marching band, say, could exit a plane.

Clever

Brilliant! I Would love to see this improvement.

This looks incredibly cool, you are surely a very good man

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