But if you've been a passenger on  American Airlines this summer, the odds are pretty good that your flight was late. And there's a clear reason why.

We're talking statistically of course. In April about 83 percent of American flights were on time--good enough for 10th place among U.S. airlines. In July that dropped to just over 72, and with it American fell to 15th place, according to airline data company OAG.

So, the company's president, Robert Ison, offered an explanation for American Airlines's bad performance--an impressively honest one. 

One of the key reasons he cited? It's a bit surprising: American has a lot of old planes, he reportedly said. Old planes simply break down and need maintenance more often. 

An honest answer

I think American gets an A for honesty on that one. It's not the most flattering thing to focus people on about your airline: how old your fleet is. Although, obviously if you're a passenger, you'd much rather that American Airlines stays on top of maintenance issues. 

Is it reassuring to remind passengers that American's fleet has so many old planes?

P​robably not--but then it's not clear that explanation was meant for passengers to hear, as the employee forum was off-the-record last month (but reported by Gary Leff this week at View From the Wing).

By the way, I reached out to American Airlines for confirmation, or context, or any comment whatsoever about all this, but never got a reply. So here's what we know.

The old planes

Ison apparently talked about three kinds of old planes that he said were partly responsible:

  1. MD-80s. These aircraft haven't been produced since the late 1990s, but American is still flying about 140 of them. They're all slated to be replaced soon.
  2. Boeing 767s. Isom grouped these together with the MD-80s. They're on the way out too. "We suffered through a month for sure where we had about 25% of our aircraft that needed spares almost," Isom reportedly said.
  3. Boeing 787s. "These were reliable when they came into the fleet after some 'teething pains,'" Leff quotes Isom as saying, but "we've seen some degradation in performance that have been due to airframes and engines and components." And that means lots of maintenance work.

To be sure, he also says there are other things to blame for American's poor on-time performance recently as well. So let's unpack those, too. 

Southwest Airlines

For one thing, he cited the fact that Southwest Airlines suffered a catastrophic engine failure on a Boeing 737 earlier this year.

Bear with us on this one: The rationale is that Southwest's tragedy meant that American had to take its 737s out of service in order to "put over 600 engines through check"--two one each airplane.

Of course, other airlines had to check their 737s as well, but 14 of them didn't come in 15th for on-time performance in July.

And the weather

Also: the weather. That's the other reason he cited. In fact, American's managing director of operations at LaGuardia had the same message on this in a separate statement Friday.

And sure enough, it's been an interesting summer for weather in the United States. Heck, there's a biblical rainstorm outside right as I write this.

Hmmm, don't all U.S. airlines have to deal with the weather in the United States? Somehow, American has stood out as a sort of "last among equals."

But at least they're honest about it. American doesn't want its planes to be delayed anymore than passengers do.