Earlier I wrote about an incident that occurred Friday morning after an EVA Air 777 bound for Taipei took off from Los Angeles. There was a serious miscommunication between the pilots and air traffic control, to the point that the 777 allegedly only cleared a mountain by about 500 feet. On top of that, visibility was limited and it was nighttime.

While we’ve heard certain snippets of the ATC audio, there’s now a full recording of the communication between the pilots and controller, along with a map of where the plane was flying. The level of miscommunication here is alarming.

To summarize the sequence of events:

After takeoff the pilots and ATC are in agreement that the plane should be flying at a heading of 090

Part of the audio is cut out (which may be part of the issue), but ATC advises the pilots to climb to 7,000 feet, and the pilots read that back as turning left heading 180 (which would translate to a 270 degree left turn rather than a 90 degree right turn) and climbing to 7,000 feet; ATC doesn’t correct the pilots when they read that back (and the whole point of reading back is to confirm that they understood the instructions correctly)

Moments later ATC notices that the pilots are turning left rather than right, and tells them to expedite the right turn to 180, which the pilots read back correctly

So up until this point there’s clearly some miscommunication, though this is where ATC starts making the situation worse:

ATC tells the nearby Air Canada plane to stop their climb, then tells them to expedite their climb

ATC tells the EVA pilots to maintain an altitude of 5,000 feet rather than climbing, when they’re heading straight for a mountain that has an elevation of 5,500 feet

ATC tells the EVA pilots to turn left heading 270, which they confirm

ATC asks the pilots what they’re doing, and says “turn southbound now”; the problem is that the pilots are flying north, and they’re not sure if they should turn left or right in order to fly south, and you can hear their confusion, as they say “left… right…”

The pilots specifically ask the controller to confirm the heading, and the controller once again says “turn southbound” (which is not a “heading” in ATC lingo)

ATC mixes up words even further and says “I see you going southbound, northbound, turn south now”

The EVA pilot is heard asking ATC if they should make a left turn, and there’s no response, other than saying to “turn south now”

EVA pilots finally respond that they’ll turn right to heading 180, and then things slowly get back on track

Having now heard the audio while also watching the flight’s track, all I can think is what a freaking mess this was. It seems odd that the EVA pilots thought they should turn left to fly south (which was a 270 degree turn rather than 90 degree turn), but at the same time that’s exactly what they read back.

The subsequent miscommunication seems to be somewhat of a language barrier, and that seems to largely have to do with ATC using non-standard terminology. The controller keeps telling the pilots to turn “southbound,” rather than giving an actual heading, as she should have. It’s especially confusing since the pilots were flying northbound, and you can hear them asking for clarification as to whether they should turn left or right.

When I’ve listened to air traffic controllers in emergencies much more serious than this, I’ve always been impressed by how calm and clear the controllers were. In this case I can’t help but feel like the controller was only making the situation worse.

Again, thank goodness this ended okay, and I’ll be curious to see what comes of the investigation (though I think listening to the audio answers a lot of questions people may have had).

What do you make of this situation — are the pilots, controller, or both, at fault?