Meet Boeing's new best friend. So far this year, United Continental accounts for more than half of the orders for new 737s. Image source: Boeing.

The month of March came in like a lion for Boeing (BA 0.80%) -- and April's starting to look pretty darn leonine for the airplane maker as well.

Seattle-based Boeing succeeded in booking no fewer than 69 new plane orders in March, including a 767-300F freighter (for FedEx), four 747-8F freighters (destination unknown), four 777-300ERs, and no fewer than five dozen 737s (a mix of -NG variants and MAXes, including two 737-800s destined to become new Navy P-8A Poseidons).

Precisely how all of the above will stack up against archrival Airbus' (EADSY 0.20%) performance remains to be seen, as Airbus has not yet released its March results. But honestly, Boeing's not even looking in its rearview mirror anymore.

April showers plane orders on Boeing
On Thursday, Boeing issued its order book update for the first week of April -- and it was a good one. Over the course of the week (which included a couple of March days), Boeing landed 17 new orders, including a 777 purchased by FedEx, the aforementioned four 747 freighters, and a dozen 737s to boot.

Because there's some overlap between the March results and Boeing's early April tally, those results may look a bit jumbled. Let's smooth them out, and get the full picture of how things look for Boeing year-to-date. So far this year, Boeing has booked:

  • 123 new orders for single-aisle Boeing 737s
  • 11 orders for widebody 777s
  • four 747s
  • one order for a Boeing 767
  • and one order for a 787 widebody.

That's 140 gross orders in all. Minus 18 cancellations year-to-date, Boeing has now amassed 122 net new plane orders on its 2016 order book.

What this means to investors
Combined, these new orders work out to a list-price value somewhere north of $16 billion. That sounds like good news for Boeing (and it is, even with the caveat that those list prices overstate what the planes actually sell for in the real world). But with these planes due for delivery years from now, the revenue effect won't be felt for quite some time.

So why are these numbers important today? In part, it's because they show the relative ascendancy of Boeing over Airbus after years of lagging its rival. Simply put, they tell us who is gaining market share -- and who is losing it.

Beyond that, these companies' order tallies also give us a clue about where the broader aircraft industry is heading -- something that should interest investors in both Boeing and Airbus. To wit, when last we checked in on Airbus, backlog at the European plane maker had begun falling, with new orders failing to come in fast enough to replace planes being completed and delivered to customers. And now here at Boeing, we're seeing the same thing happen.

Despite Boeing raking in significant sales gains in March and April, its backlog number currently stands at just 5,740 planes -- 55 planes fewer than what Boeing had in backlog at the end of January. Granted, if the company keeps winning plane orders at the rate it's been doing, the trend could reverse yet again, and its backlog could grow. Granted too, in conversations I've had with Boeing management, the execs are not worried one bit, and remain supremely confident that air traffic globally, and demand for new airplanes, will continue to rise.

But at the present moment, right here, today -- the trend is heading down.