Code Shares and Airplane Thrust Reversals

All right, so I outlined the workings of airline code-shares, but to at least one reader’s dismay I neglected to address the terminology itself. Code-share? The “code” refers to an airline’s specific two-letter identifier assigned by IATA, the International Air Transport Association. IATA is a trade organization comprising hundreds of airlines around the globe. Every airline has an IATA code. In the cases of our Big Three, for example, they are UA, AA, and DL. These are technically part of every flight number, though in the US we routinely drop the letters. Flying Air France’s Concorde from JFK to Paris, for instance, your trip is AF001. In a code-share situation, a specific flight is split among two or more airlines and their respective prefix designators.

To make it as confusing as possible, the number part also will vary. Delta’s flight DL8718 might also operate as Air France’s flight AF718. Same plane, different flight number (notice the 8 is dropped). If you’re confused about which airline you actually are flying on, always look at the lower number. In the above example, Delta might have sold you a ticket, but Air France will be serving the coffee.

Everyone with me?

Meanwhile, in last week’s discussion of reverse thrust, I made this simple parenthetical statement: (No, neither jets nor turboprops will reverse during flight.) I wanted to avoid an in-depth discussion of the matter, but yes, as assorted nitpickers so ardently pointed out, airplanes can reverse in flight. Sure, just as your Honda can drive backwards down the interstate. My point was that an airliner will not do so as a matter of routine. Most all planes have apparatus to prohibit inadvertent reversal in flight. At least one model, though, the old Douglas DC-8, was authorized to reverse its engines (inboard only) while aloft.

In 1991 a Boeing 767 operated by Lauda Air, a highly regarded Austrian charter company, suffered an uncommanded inflight reversal of its left engine after takeoff from Bangkok. The airplane crashed into the Thai jungle killing more than 200 people. Boeing later redesigned the thrust reverse system.

This article is part of a collection that originally appeared on Patrick Smith, 38, is an erstwhile airline pilot, retired punk rocker and air travel columnist. His book, Ask the Pilot (Riverhead) was voted “Best Travel Book of 2004” by Patrick has traveled to more than 55 countries and always asks for a window seat. He lives near Boston.