It was, according to The Wall Street Journal, "the largest deal for commercial aircraft in aviation history."

On Feb. 14, 2023, Air India Ltd. announced an agreement to purchase 190 single-aisle 737 MAX airliners, 20 twin-aisle 787 Dreamliners, and 10 larger 777X widebodies from Boeing (BA 0.63%) -- 220 airplanes in all, and with an option to buy 70 more. But even then, the Indian commercial airline wasn't finished, announcing it would also buy 210 single-aisle A320 jets and 40 A350 wide-bodies from Airbus (EADSY 2.21%)

So make that 470 airplanes ordered (and potentially eventually 540). All on a single day.

How much are 470 airplanes worth?

Even if Air India never exercises its Boeing options, and the airline buys "only" 470 airplanes in total, this is still a pretty big deal, surpassing the previous sales record set in 2011 when American Airlines placed orders for 460 airplanes -- also split between Boeing and Airbus.

But precisely how big of a deal is it in dollars and cents?

As the Journal pointed out, airlines and their airplane suppliers routinely play coy on the details of mega-deals like this one, playing up the "list price" of the airplanes in question, but hiding the actual purchase cost. In this present case, the published list prices for Boeing's 220 airplanes total $45.9 billion. Airbus no longer publishes its list prices, but WSJ notes that the combined MSRP on all 470 planes in the initial orders comes to "around $85 billion" -- so figure Airbus's take is about $39.1 billion for 250 planes.

Put the two totals back together, and at $85 billion in total list price-value, this month's airplane mega-deal is worth $10 billion more than the previous record -- an Emirates Airline order for $75 billion for several Boeing 777X planes.

And how much are 220 airplanes worth to Boeing?

And yet, the question investors need answered doesn't concern list prices at all. What we really need to know is: How much actual revenue will Boeing get out of this sale, after the discounts that no one wants to talk about?

Because these discounts can be very significant.

Simpleflying.com calls list prices on aircraft "something of a farce," and explains that the reason Airbus doesn't even publish them anymore is precisely because list prices are unhinged from reality. In fact, digging into the research on the phenomenon of airplane deep-discounting some years ago, I discovered examples of actual airplane purchase prices being discounted by anywhere from 44% to 58% off of list prices

For this reason, a conservative investor should probably anticipate that the actual revenue Boeing will receive from this "largest deal for commercial aircraft in aviation history" will be quite a bit less than the $45.9 billion list price on it, and perhaps as little as half the list price.

There's even less assurance that this revenue will be immediately profitable for Boeing. After all, data from S&P Global Market Intelligence show that it's been four years since the last time Boeing's Commercial Airplanes division earned even an operating profitEven before COVID-19 threw a monkey wrench in the commercial airline industry, Boeing was losing money because of ongoing difficulties with its 787 and 737 models. And just last week we learned that the company has halted Dreamliner deliveries to fix issues with the plane's forward pressure bulkheads. 

All of this is to say: Reviving demand for airliners in the wake of the pandemic bodes well for Boeing getting back to profitability eventually. It may even get back to profitability soon. But so long as production problems continue to dog Boeing, it also might not earn all the profits you expect, despite its participation in the biggest airplane sale in history.

The upshot for Boeing

With that caution in mind, even a large fraction of $45.9 billion in revenue would still be a big number for Boeing. Were revenue to come in at even just half the list price, it would represent nearly three full quarters of revenue for Boeing's commercial airplanes division -- all booked in a single day.

With analysts forecasting that Boeing will return to profitability as early as next quarter, and that it might earn a $2-per-share profit this year -- and nearly $8 per share in 2024 -- investors are naturally optimistic that this month's order for 220 new Boeing airplanes will turbocharge Boeing's profits. They may even be right about that.

Whether they're wrong or they're right, though, at a price-to-earnings ratio of more than 25 times next year's predicted profits, and nearly 100 times this year's prediction, there's still a fair amount of risk in Boeing stock. My best advice to investors is: Don't count Boeing's profits until they've actually been earned.