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Airbus' A320 wears its biggest selling point on its sleeve. Er, its fuselage. Image source: Airbus.

Well, that was quick. As recently as Thursday, I was writing about how Boeing (NYSE:BA) had pulled out of its August sales slump, and landed a rollicking 70 new orders for its Boeing 737 airplane last week. Plus the occasional airplane order here and there over the preceding weeks of August, this left Boeing with 505 gross plane orders at the start of September. Minus a total of 58 orders canceled year to date, and Boeing's net plane orders now stand at 447.

But just a day after that tally came out, Airbus (NASDAQOTH: EADSY) released its own sales report for August. And would you care to guess how many planes Airbus sold?

Would you guess 346?

Airbus' boffo sales month
According to the European plane-making giant, Airbus received orders for 33 widebody aircraft, including 25 A330 aircraft and eight A350s -- mostly from customers whose identities have not yet been disclosed.

Single-aisle jets sold even more briskly. August also saw customers such as India's IndiGo, British Airways, and Vueling (which, according to S&P Capital IQ, is a midsize, privately held Spanish airline) order a total of 313 A320 aircraft in both "neo" and "ceo" configurations. Airbus says that with these orders in hand, it has now sold more than 12,000 A320 Family aircraft, of which more than 5,400 still sit in backlog, waiting to be built.

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August is amazing for Airbus airplane sales. Image source: Airbus.

The tally
All of which adds up to an Airbus order book now brimming with orders for 662 single-aisle "A320 Family" jets (which include a tiny A318, two A319s, and 111 A321s), 83 widebody A330s (which compete with Boeing's 767, 777, and 787), and nine A350 widebodies -- but not a single A380 superjumbo jet.

That's 754 gross new plane orders so far this year. Minus 46 cancellations (fewer than Boeing, and deducted from a larger gross total), this leaves Airbus with net new plane orders of 708 at the beginning of September.

The race
As Airbus is quick to point out, that's not only 58% more airplane orders than Boeing has netted this year, it also gives Airbus "the industry record backlog of 6,697 aircraft overall," which is enough orders to keep Airbus factories humming for the next 10 years straight, at current production rates.

In contrast, Boeing's backlog today stands at "only" 5,710 planes. At current production rates, it would take Boeing about 8.5 years to work its way through just the 737 single-aisle portion of that order book. Which is why Boeing is accelerating production by as much as 24% over the next three years.

All of which is true, but all of which suggests we're rapidly approaching the "law of big numbers" -- where numbers begin to lose their meaning because they're all just so mind-bogglingly big. Even if this is the case, though, there are still two big truths that jump out of the plane order reports we saw last week.

First: Airbus is now crushing Boeing in the race to book the most plane orders in 2015 -- just as it beat Boeing in this race last year.

Second, and perhaps most important: Both of these companies are doing amazingly well. Eight-point-five years' worth of business in the bag? Ten years' worth of plane orders to fulfill? That's just a huge amount of sales success, and it gives us great visibility into the future revenue streams of both Boeing and Airbus.

The upshot for investors
Granted, it's still a bit of a tossup as to which of these airplane makers is the better stock to invest in. On one hand, Boeing is doing a better job than Airbus on deliveries, rakes in 36% more revenues annually than its rival, and boasts an 8% operating profit margin on its sales -- nearly twice what Airbus earns.

On the other hand, Airbus has the bigger order book, is adding to that order book at the faster clip, sells for a cheaper P/E ratio (15.7 versus Boeing's 17.6), and is expected to grow earnings faster (at least, according to analysts cited on S&P Capital IQ).

Whether you bet on the dark horse (Airbus) or the incumbent most-valuable-stock (Boeing), I really suspect you can't go far wrong by investing in either of these companies.

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Boeing sells a lot of pretty 737s, too. Image source: Boeing.

Rich Smith does not own shares of, nor is he short, any company named above. You can find him on Motley Fool CAPS, publicly pontificating under the handle TMFDitty, where he's currently ranked No. 267 out of more than 75,000 rated members.

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