My first reaction to aircrafts was to think it was a typo, but I just checked usage on NGrams...

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...and compared it to usage for the singular / collective noun form aircraft...

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...which seems to indicate that the "regular" plural form is gradually being taken up. Does this represent a tendency for English speakers to enforce regularity on the language? Are there any other examples? I'm not expecting to find that "sheeps", for example, is displacing "sheep" for the plural meaning, but maybe there are other "less established" usages that could be changing.

EDIT Please note that I'm not asking whether "aircrafts" is correct, or common. I'm asking if there's any reason why it seems to be occurring more often over recent decades (even though it's still pretty rare). And whether this effect occurs with other nouns having "non-standard" plural forms.

  • 8
    I've never heard aircrafts from native speakers.
    – mgb
    Commented Oct 31, 2011 at 19:05
  • 4
    My experience is English speakers from the Indian subcontinent rarely use collective nouns as plurals and tend to create 'standardized' plurals.
    – Affe
    Commented Oct 31, 2011 at 20:22
  • @Affe: I have to say that so far your comment seems to be the only contribution here that actually addresses my question. I don't know how we could establish the truth of what you say, but if it were so it might easily be enough to explain the phenomenon I seem to be looking at in NGrams. Commented Oct 31, 2011 at 21:47
  • 1
    There's probably a linguist somewhere who's actually studied it :) All I can offer is the anecdotal testimony of an engineer who's been tasked with american-izing documents delivered by outsourced technical teams many times over the course of his career.
    – Affe
    Commented Oct 31, 2011 at 21:52
  • 1
    In today's (reputedly conservative) Daily Telegraph (13/07/13): "Shares in Boeing took a nosedive on Friday after one of its Dreamliner 787 aircrafts caught fire while parked at Heathrow, closing the airport"
    – user47705
    Commented Jul 13, 2013 at 8:56

5 Answers 5


Well, this is an example of why Google NGrams isn't a precise indicator. When we compare the two directly, aircrafts simply can't get off the ground:

aircraft vs. aircrafts

Now, this result is also flawed since it is impossible to separate uses of aircraft (singular) and aircraft (plural). It is also impossible to factor out typos (aircrafts vs. aircraft's) and so on.

The point is, don't read too much into what an NGram shows (or at least take the graphs with a grain of salt), because a great deal of the time what you wind up with is this sort of thing:

apples vs. oranges

(BTW, the huge spike in the use of aircraft in the early '40s is almost certainly due to the air war in Europe and the Pacific.)

  • 1
    Per my comment to @drɱ65's answer, I know perfectly well that aircrafts is relatively uncommon. I'm only concerned with the apparent trend for aircrafts to occur more often in recent decades. I don't see how aircrafts vs. aircraft's makes any difference to that unless you attribute it to such typos becoming more common in later printing - which may indeed be the case, but I've no reason to think it so. Commented Oct 31, 2011 at 21:43
  • @Fum: Well, if it's a trend you see, it's one that isn't likely to overtake the other in the next millennium or two.
    – Robusto
    Commented Nov 1, 2011 at 0:15

Graphing some aircraft against some aircrafts shows that the latter is still quite uncommon compared to the former:

I would say that such as it is, it represents a tendency for non-native English speakers to emulate regularity when they do not know that the plural is irregular.

  • 2
    and similarly with two aircraft
    – Henry
    Commented Oct 31, 2011 at 19:42
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    The reason I graphed aircrafts/aircraft separately in my question was because the former would have simply "flatlined" otherwise. But looked at in isolation, aircrafts does seem to be on the increase. @Affe's comment on the question may well be significant; perhaps increasing numbers of Indian usages are skewing things to their own inclinations. Commented Oct 31, 2011 at 21:37
  • Did you click through to some of the aircrafts to check their source?
    – Hugo
    Commented Nov 1, 2011 at 6:54
  • 1
    I think my answer does address the question. There is an increasing amount of written non-native English, and non-native English includes nontraditional attempts toward regular plurals. So we would expect to see an increasing amount of plurals like aircrafts.
    – Daniel
    Commented Nov 1, 2011 at 15:21

I don't think there's any way to answer this question definitively. All we're doing is speculating. So I'll offer a few speculative theories:

As use of a word rises, so does misuse of a word.

Aircraft saw an increase in usage between 1970 and 1990... and so did aircrafts. Aircraft then trended downward after 1990 and so did aircrafts. Softwares is also on an up-trend, mirroring the trend of software. Interestingly: Sheep saw an uptick in usage around 1910, and so did sheeps. Who knew?

Edit to clarify: In other words: If we speculate that X% of people mis-use aircrafts, as aircraft becomes more widely used, so will aircrafts. @FumbleFingers has pointed out that the use of aircrafts has increased more than use of aircraft. That may be so, but I don't think it invalidates this theory as a contributor to the overall uptick in use of aircrafts.

More writing = More mistakes

The sheer body of work increased dramatically in recent years - 3 billion ngrams in 1970 versus 13 billion in 2000. With writing becoming more accessible to a wider audience, it stands to reason there would be more potential for incorrect word use.

Edit to clarify: Again, simply: If aircraft appears a million times more often, that's a million more chances for typos, mistaken word choice, or things slipping through a proofreader.

English Takes a Beating

Sites like this non-withstanding, I think there's been a pretty clear trend (in the US anyway) away from proper grammar and spelling. As education takes a nosedive, one would expect word misuse to increase. Some folks in other answers have blamed non-native speakers, and maybe that's a part of it, but I think the native speakers are as bad as anyone in this regard :)

  • My NGram has nearly 291,000 written instances of aircraft. I don't see how that's small enough to say the sample size skews anything. More writing = more mistakes, sure - but the only relevant change is the higher percentage of mistakes. I assume you mean wider access to publishing facilities means either incompetent writers can now use them, or proofreaders can't keep up with the increased workload. In my experience people who can't write, don't. Not in print, anyways! :) Commented Nov 2, 2011 at 1:55
  • I was referring to the sample size of aircrafts. The jump looks bigger because there are so few instances of it to start with.
    – Lynn
    Commented Nov 2, 2011 at 2:37
  • Oops my mistake - I meant 291,000 for aircrafts. Which is small compared to the 57M for aircraft, but big enough for the graph not to be skewed by anomalies arising from a small sample size. But after the leap in the 40s (caused by WW2, no doubt), aircraft has remained static for several decades, whereas aircrafts has easily doubled in frequency over the same period. Commented Nov 2, 2011 at 4:04
  • You're right, 291k is non-trivial. All meant was that there's a little 'hump' of increased usage in the ngram graphs for both aircraft and aircrafts between 1970 and 1990. The hump on aircrafts looks really dramatic, but the scale on the graph is actually quite small. In that time period, aircraft jumped in use by .001% (in the overall corpus) whereas aircrafts jumped in use by only .000001%. My assertion was that the use of aircrafts increased only a small amount compared to the overall increase in use of the standard form. But perhaps I'm misinterpreting the data.
    – Lynn
    Commented Nov 2, 2011 at 5:13
  • Well I'm only really taking issue with the way you reference the data to support your conclusions, not the conclusions themselves. Which seem to be (a) illiteracy is on the increase, and (b) more non-native speakers now write in English. I don't know how to count the number of instances for any specific period of time, because NGrams invariably gives hopelessly misleading values when it says about nnnn results, and I'm not going to page through the whole lot until it finally admits there are actually far less than it originally estimated! Commented Nov 2, 2011 at 13:51

In general, linguistically speaking, speakers tend to veer more towards regularizing non-standard forms.

It's a common characteristic of socio-linguistic change. If we didn't have dictionaries and style guides in English, it would probably happen a lot more often that it does. Up until the last century, only a small proportion of society could even read and write.

Now that we have

  • more people writing than ever before (regardless of education level and concern for linguistic accuracy), not to mention
  • more non-native English speakers writing English than ever before and
  • who by default seek standard rules because it's easier than memorizing exceptions,

it's only natural that we'll see an increase in trends toward regularization.


No red squiggly line!

Well I have a very simple reason why it IS probably used or seen more. At one time people cared about spelling and grammar.

But now we rely on Microsoft Office and Word's spell check abilities. Hate to say it but "aircrafts" successfully passes the Office spell check (my version is 2010).

  • Aha, so it is a Microsoft bug!
    – Dronz
    Commented Nov 30, 2014 at 20:43

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