flight number board

Have you ever stopped to think about what (if anything) your flight number means? It turns out that those codes identifying each flight aren’t just made up of random strings of numbers and letters. There’s actual significance behind your flight number and understanding it could mean the difference between ending up on a good flight or a terrible one.

Mental Floss has a great write-up deciphering the meaning behind flight numbers and it takes you through both the obvious and the not-so-obvious. Obvious: the letters preceding the flight number stand for the airline operating the flight (so AA is American Airlines, UA is United Airlines and so on). Not so obvious: Flights with even numbers are traveling east or northbound while flights with odd numbers are heading west or south. Other interesting tidbits: outbound and return flights between the same destination usually have call numbers one digit apart, and flights that have low numbers (one or two digits) are usually the carrier’s most popular routes.

It’s all very fascinating and I’d encourage you to read the whole article, but as a traveler, does any of it really matter? Well, yes. I think there’s one circumstance where understanding your flight number is truly worthwhile and that’s when you’re on a code share.

A code share, in case you’re unaware, is where your flight is ticketed by one airline (say, United) but the plane that you’re flying on is operated by another airline (e.g. Air Canada).

I learned the importance of understanding code shares the hard way after a travel agent (this was back in the day) booked me on what I thought would be a nice Qantas flight with plenty of in-flight entertainment and amenities. In reality, I spent 10 hours on a China Eastern Airlines Flight with nothing but a static-y Chinese movie on one of those small overhead screens for entertainment… and I don’t speak Chinese. Lessons learned: always pack a book on a flight and always check for scary, evil code shares.

On the flip side, here’s another reason I think understanding code shares is a good idea: collecting frequent flier miles. If you ever want to be able to redeem your miles, you’ll need to amass lots of points with one particular airline (as opposed to picking up a handful of award miles across a bunch of different carriers). By recognizing code shares when making your booking, you can choose to fly one airline (which may be nicer) while earning frequent flier points with another (your regular airline). Talk about having your cake and eating it too. So code shares are not always scary and evil, and depending on your goals, they could actually be a good thing.

So how do you spot a code share? In general, it’ll be noted on the itinerary the airline emails you (look for the words “operated by”), but for the reasons mentioned above, you’ll probably want to know about the code share before you make the booking. So check the flight number. According to Mental Floss, if your flight number has four digits and starts with the number 3 or higher, it’s probably a code share. Of course, nothing beats picking up the phone and calling the airline to be extra sure.

[Photo credit: Michael Kappel, Flickr]