( CNN ) As relatives and friends mourn the loss of their loved ones aboard Germanwings Flight 9525 , the world community is stunned by the sequence of events that led to co-pilot Andreas Lubitz purposely crashing the plane into the French Alps , killing all 150 people on board . I happen to have several personal connections to this tragedy : a recent graduate of Drexel University -- where I teach -- and her mother were on the ill-fated flight , I lived in Germany for 18 years and I am a psychologist who has researched the psychology of terrorism and developed psychiatric tests that are used to determine pilot flight fitness . While the engineering of the Airbus aircraft is fascinating and the world of air traffic control absorbing , what is even more complex and challenging to understand is the human mind of the co-pilot investigators say is responsible for the crash -- the machine that flies the machine . When complex engineering systems interact with human factors , it is most often the human that causes the anomaly . Humans are far less reliable than machines . The average aviator has superior intellectual and cognitive abilities , and is psychologically stable and reliable . While it is not surprising that when it comes to aviation accidents , the first line of inquiry is into what went wrong with the plane . However , very often , as apparently is the case here , something went wrong with the human flying the plane . Pilots are typically tested for emotional stability and screened for the presence of mental illness when they are selected . The U.S. Navy has strict testing programs related to fitness for duty protocols for their pilots during the length of their careers . But we have learned that the German company Lufthansa and its budget airline affiliate Germanwings do not use psychological testing once the pilots have made it through the selection process . Psychological assessment and screening is not held in as high esteem in Germany as it is in the United States . Perhaps it should be . A fitness-for-duty evaluation asks this important question : Can the pilot safely and effectively perform his job from a mental health and cognitive standpoint ? The deliberate destruction of Flight 9525 by a single person , most likely related to some grievance or other unknown intrinsic motivation that he took to the grave , can also be considered an act of terrorism . The action constitutes the unlawful use of violence against the passengers on the flight to further some yet unknown objective . Research on the perpetrators of terrorism has revealed that a single person is capable of executing odd , unexplainable violent actions . Their behaviors may be related to a political or social framework , or it may be associated with something deeply personal . Examples include Richard Reid , the failed shoe bomber ; Eric Rudolph , the Olympic bomber ; or Theodore Kaczynski , the Unabomber . In 2009 , Maj. Nidal Malik Hasan , a U.S. Army officer and psychiatrist , went on a shooting spree at Fort Hood , Texas , killing 13 and wounding 32 . And in 2012 , Staff Sgt . Robert Bales , a 38-year-old father of two , opened fire and killed 16 innocent Afghan civilians . When examining Germanwings Flight 9525 from the `` cockpit of the human mind , '' one must ask this question : How can we ever predict or prevent tragedies like these when we can never truly know what lurks in the mind of another human being ? As a psychologist , I would , of course , advocate for more rigorous psychological screening and regular testing for pilots , as well as instituting additional security measures to prevent future incidents like this . Just as aircraft are inspected and maintained , it is important to regularly evaluate one of the more fragile components of modern aviation -- the pilots operating the plane . But , just as the overwhelming majority of automobile accidents are caused by driver error , with a human mind at the helm of an aircraft , there will always be an element of unpredictability present . And , unless we had a `` flight recorder '' for the human brain , we will never really know what took place inside the mind of co-pilot Andreas Lubitz . One thing is for sure : the tragic events of Flight 9525 will surely renew conversation about what happened to Flight MH370 -- the biggest aviation mystery since Amelia Earhart vanished in 1937 -- and the role that human factors may have played in its disappearance .
Eric Zillmer : It 's hard to predict or prevent tragedies like the Germanwings crash . He says German airlines should consider more rigorous psychological screening and testing for pilots .