More arrivals or departures?
December 12, 2011 8:47 AM   Subscribe

Are there more arriving or departing flights in the United States? Bonus: previous years, other countries, domestic vs. international, etc.
posted by michaelh to Travel & Transportation (16 answers total) 1 user marked this as a favorite
They should be equal. If there an imbalance between arrivals and departures, where would the planes for those "extra" flights come from?
posted by misterbrandt at 8:51 AM on December 12, 2011 [4 favorites]

I'm not sure whether you mean within the US or international, but either way it seems like there would be the same number of each. When a plane takes off, it generally lands again, and when it leaves, it usually comes back.
posted by attercoppe at 8:53 AM on December 12, 2011

They'd have to be pretty nearly equivalent, otherwise you'd end up with an excess or dearth, respectively, of airplanes in the United States. I.e., if you had 3 more arrivals than departures per day, at the end of the year there'd be ~1100 more planes in the US than there were at the start of the year.

Very small inequalities could be created by planes built in the US and taken out of service (either deliberately or due to accident) outside the US, or vice versa, but it seems that number would be miniscule compared to the total number of flights.
posted by DevilsAdvocate at 8:55 AM on December 12, 2011

The arrivals and departures are equal. The airlines really don't want to fly an airplane somewhere with passengers and then fly it out empty to position it somewhere else. A large part of airline schedule planning is of the form "we need to move X passengers from A to B, how to we get a plane of sufficient size to A?" while matching the size of the plane as closely as possible to the potential number of passengers. A number of red-eye/oddly scheduled flights really exist for pre-positioning purposes.
posted by Runes at 8:56 AM on December 12, 2011

Well, I actually am interested in even the slightest difference.
posted by michaelh at 8:56 AM on December 12, 2011

No, it doesn't have to be perfectly equal (but it would be nearly equivalent), considering that each plane can carry different numbers of passengers, and planes can stay overseas for extended periods to carry passengers in other countries.

Moreover, airlines would limit flights to try and pack as many people into the plane as possible. It's cheaper to leave a plane on the ground than fly a nearly empty plane.

This would vary seasonally, for tourist seasons and holidays.
posted by Cool Papa Bell at 9:00 AM on December 12, 2011

Well, for domestic flights, the number of departures will exceed the number of arrivals by the number of domestic flights which crash (for some suitable definition of "crash," e.g., one which includes a landing on the Hudson River in which all passengers and crew survive).

Plus, if you're looking at a very specific down-to-the-minute time frame (e.g., 00:00 EST 01 Jan 2010 - 00:00 EST 01 Jan 2011), planes in the air at the start of the period arrive but do not depart within that period, and vice versa for planes in the air at the end of the period. I.e., if there were no crashes in that period, the number of departures would exceed the number of arrivals by (domestic flights in the air at 00:00 EST 01 Jan 2011) - (domestic flights in the air at 00:00 EST 01 Jan 2010), with a negative result indicating that arrivals exceeded departures.
posted by DevilsAdvocate at 9:07 AM on December 12, 2011

The U.S. Department of Transportation runs a site called TranStats, which looks like a good place to get this information.
posted by Diggins at 9:08 AM on December 12, 2011

Aside from the whole question of flights in being approximately equal to flights out, I can see how you could be asking about planes manufactured in the US which are then shipped to the overseas buyer by being flown there. Or planes purchased for US use from a foreign manufacturer. Or planes formerly part of a US-based fleet that were sold second-hand to a foreign airline. Or planes that are shipped by sea from here to there (for repairs) and flown back again. Or planes that don't pass inspection and are taken out of service. Depending on the time period you're interested in, cancellation of an international flight that converts a particular machine from international routes to domestic routes could add one to the tally, but over a longer period, a different plane would take its place, so the net should be zero.
posted by aimedwander at 9:22 AM on December 12, 2011

Yes, I am interested in all possible reasons why the numbers would not add up. Even if they did add up, I would be interested to hear about two different causes of unevenness that cancelled each other out.
posted by michaelh at 9:30 AM on December 12, 2011

Being as a lot of planes are manufactured in the US, then I imagine there will be more leaving than arriving. Deliveries of planes to foreign airlines would be a factor, as well as new planes into US fleets causing older planes to be sold off to (potentially) foreign customers.

With planes being manufactured inside the US this is likely to skew your data (for whatever reason you need to know this!). So you'd see more flights out than in for that reason alone.
posted by Brockles at 9:54 AM on December 12, 2011

As well as the crash factor slightly reducing the number of arrivals vs departures, possibly the fact that one of the two major manufacturers of airliners -- Boeing -- is located in the US will tip it slightly further. A 777 sold to Qantas will depart the US and arrive in Australia before it begins regular service. It would depend of course, on if foreign airlines buy more Boeings that American carriers buy Airbuses, but I have a hunch this is the case. (Or on preview, what brockles said.)

As an aside, Simon Winchester wrote a great piece a few years ago (in Harpers? The Atlantic?) that talked about Boeing's sales process. As I recollect, the carrier makes a down payment of perhaps 20% when construction begins and several more small payments as it is in progress, but the final payment isn't until the day the airplane is turned over. Because the carrier wants to delay payment as long as possible (a 767 costs between $100 and $200 million, so every day you can hang on to your cash is a day it generates interest) and Boeing does not want to pay sales tax on such huge purchases, a complicated dance ensues: the plane departs the Boeing plant in Everett, Washington with two flight crews aboard -- one from Boeing, one from the purchasing airline -- and heads out over the Pacific. Once the territorial limit is passed and the plane is over international waters, contact is made with the waiting lawyers for the carrier and Boeing, who are sitting in an office somewhere. The final transfer is made, title is handed over, and the Boeing crew unbuckles and vacates their seats to allow the carrier's crew to take over. Thus every Boeing plane is sold when it is five miles in the air and two hundred miles off the West Coast of the USA.
posted by ricochet biscuit at 9:59 AM on December 12, 2011 [3 favorites]

There will be more departures, I believe. My logic for the differences is as follows:
1) US made commercial aircraft are likely pretty close in import/export numbers, with a slight edge to imports, which would account for one additional import per plane. This number is fairly small, I assume because there are only about 18,000 passenger aircraft in the world. I believe there are more imports because by count, the biggest segment is probably small planes and Embraer and Bombardiar clearly dominate that category and are both imports. Boeing probably exports more planes than Airbus imports, but those numbers are quite small compared to the regional jet totals.
2) The overwhelming majority of general aviation aircraft are US-made. Cessna and Piper account for the vast majority of genera aviation aircraft and there are at least 312,000 GA airplanes in existence. Even though there are more GA planes in the US, I'm confident that exports must outnumber imports.
3) As far as I know, the US doesn't have a single foreign made military aircraft. We do manufacture and export a significant number of military aircraft for other countries and there are 89,000 military aircraft in the world.

My conclusion is that the number of GA aircraft made in the US and exported and the military aircraft mean that US is a net exporter of aircraft by the numbers and therefore we have more flights in than out. Most of my numbers were derived from this Google Answers post which looked pretty accurate to me.

There is also a final factor, which is the sale of used aircraft. I suspect that far more used airplanes are sold from the US to foreign destinations than the reverse. I know that this is certainly true for passenger airplanes and I suspect this is also true for GA airplanes as well.
posted by Lame_username at 10:02 AM on December 12, 2011 [1 favorite]

ICAO collects this data. They've moved a bunch of stuff behind the paywall in the last year, but I'd guess some judicious google work would get you the actual answer.
posted by JPD at 10:24 AM on December 12, 2011

The biggest aircraft
posted by trialex at 1:16 PM on December 12, 2011


The biggest aircraft boneyards are in the US too, so aircraft coming back to the US to be put out to pasture probably cancel out some of the new aircraft being flown out to be delivered to customers.
posted by trialex at 1:17 PM on December 12, 2011

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