Wired published a relatively lengthy article on the incident(s):

https://www.wired.com/2015/05/feds-say-banned-researcher-com...

I think the poster you're replying to is mis-remembering. I'm not sure. IIRC, there was an article alleging that a passenger managed to force a slight turn of an aircraft, but subsequent investigation turned up evidence suggesting it didn't actually happen. Or at least I don't think there was any evidence the engines were under the hacker's control for any length of time.

The only articles I could find were these:

https://news.ycombinator.com/item?id=5531679

https://news.ycombinator.com/item?id=8139905

https://news.ycombinator.com/item?id=9402336

But the first one makes some rather dubious claims and doesn't align with my memory of what I believe your OP is remembering. My Google-Fu isn't working out well for me tonight (in my defense, it's late, I'm tired, and I'm reading this for entertainment...).

Edit, also these:

http://www.cnn.com/2015/05/17/us/fbi-hacker-flight-computer-...

http://www.usatoday.com/story/tech/2015/05/16/chris-roberts-...

Among others. I couldn't find the HN discussion on this, though.

Edit edit: Found the HN links:

https://news.ycombinator.com/item?id=9557875

https://news.ycombinator.com/item?id=9568050