A lot of people are asking how laptops could've caused the crew of Northwest Flight 188 to overfly MSP? According to the NTSB, using laptops on the flight deck is strictly prohibited during flight, but even a quick glance at the tray table on each side of the Airbus A320 family flight deck shows how a laptop monitor could easily block the pilot's navigation display.
The tray table is available to both crew members because Airbus uses a sidestick controller rather than the center yoke found on Boeing, Embraer and Bombardier aircraft.
At NBAA 2008 (yes 2008), I was provided a tour of the Comlux A319 ACJ and unfortunately the audio on the video was largely garbled, so the video was never used. This afternoon, I went back and looked at one portion of the video that shows the arrangement of the flight deck tray table in relation to the navigation display. I added some new audio and some annotations on the video to show just how easily a laptop could block the displays, causing a major distraction to the crew. This is why laptops aren't allowed in flight!
Read the full text of the NTSB update on Northwest 188. Also, why was the ACARS off?