All of us been guilty of multi-tasking but is it beneficial?  Research has conclusively demonstrated you can only do one cognitive activity at a time.  If you are performing an automatic physical task without a great deal of thought then perhaps that could be considered multi-tasking such as walking or driving while carrying on a conversation but even then one’s alertness may be diminished.

In our technologically rich society multi-tasking is a greater temptation than ever before.  Consider the problem of driving and texting.  Is that text message so important that you will risk an accident?  When you intently focus on a cognitive task the other senses seem to have a diminished capability. 

When I was in the navy we were reviewing an ACM (Air Combat Maneuvering) flight where the pilot disregarded the low altitude warning given by the instructor.  He said he never heard it – when the tape was replayed there was the warning – clear and distinct.  The reality is he never heard it!  He was so intent on locking in the target that his other senses basically shut down. 

Wives go easy on your husbands, when it’s late in the fourth quarter and the game is on the line and you say something to your husband he probably doesn’t hear you.  In flight school we learned this priority system:  aviate (i.e. fly the plane), navigate, communicate.  Don’t mix up the order – gravity is not just a good idea, it’s the law!

The crash of Flight 401 reveals the serious consequences of multi-tasking:

Flight 401 was approaching Miami International Airport at about 2330 local time, when the nose landing gear position indicating system light did not illuminate. The pilots had to identify whether the gear had indeed failed to extend, or more likely, that the bulb had simply burned out. As a result, the pilots aborted the landing and the first officer set the autopilot to keep the aircraft at 2000 ft to allow them to sort out the problem.

Shortly afterwards, during a discussion regarding the landing gear, the FDR (Flight Data Recorder) detected slight nose-down pressure on the captain’s control column. This coincided with the captain asking the second officer to check the gear through the avionics bay viewing window. It is likely he unknowingly bumped the control column while turning to speak with the second officer, enough for the pitch mode to swap from altitude hold to control wheel steering, which initiated a gradual descent.

Meanwhile, the captain and first officer tried to replace the bulb and confirm that the original had indeed burned out. CVR (Cockpit Voice Recorder) clearly revealed that the crew was frustrated with the problem of changing the bulb, as the cover had jammed.

Due to differences in the two pitch computers, the first officer’s display still indicated that the autopilot was in pitch mode. As the aircraft descended 250 ft below the assigned altitude of 2000 ft, an aural warning from the second officer’s speaker was detected on the CVR, but the crew seemed to be unaware of it, and by that time the second officer was already in the avionics bay. There were at least four indications that the L-1011 was slowly descending towards the Everglades. The altimeter, vertical speed indicator, the captain’s autopilot display, and the aural warning all went unnoticed by the crew.

Just a few minutes later, while the pilots were still working on the problem, the first officer noticed that the altimeter was indicating a dangerously low altitude, and then the radar altimeter sounded an altitude warning. However, by the time the pilots realized their situation it was too late; flight 401 impacted the Everglades in a left turn and began to disintegrate, the wreckage being strewn over an area of 50 square kilometers. It was the first accident involving a wide-bodied airliner, and the most deadly crash in the United States at that time.

Investigators were puzzled to subsequently discover that apart from one burned out bulb, there was nothing wrong with the L-1011. The main causal factor in this accident was not the aircraft, but the crew, the human factor.

Even though the crew was dealing with the landing gear indicator, they still could have noticed their surroundings and the aircraft’s altitude. As long as stress levels are not too high, the average human has enough additional information processing capacity to notice things unrelated to the current task, such as the aural altitude warning, and instruments indicating a descent (Robson, 2008). When stress levels increase, however, it is possible for cognitive tunnelling to develop (Chou, Madhavan, & Funk, 1996); this is where one particular task is given a very high priority at the expense of other tasks. It can be especially dangerous when the task being focused on is actually less important than those tasks being neglected. Initially, it may seem that the crew was presented with the simple task of changing a lightbulb. However, as the cover had jammed, both the captain and first officer likely experienced cognitive tunnelling as they tried to establish a way of replacing the bulb without breaking the cover.  In this case, all of their attention was given to this one small problem, at the expense of flying the aircraft.

Give yourself the freedom of doing just one thing at a time.  The Apostle Paul realized the importance of focusing on one thing at a time,

Brethren, I do not regard myself as having laid hold of it yet; but one thing I do: forgetting what lies behind and reaching forward to what lies ahead, (Philippians 3:13)

Notice Paul’s emphasis, this one thing I do, not fifty things I dabble at.  The reality is we’re not multi-tasking but multi-switching and that is inefficient.  Try focusing on one task at a time and see if you’re not only more efficient but also less stressed.