psychological or emotional issues. but government regulations are not as strict. the faa says pilots can't fly if they have bipolar or similar problems. pilots have to under go a medical exam every year or six months. he says those examines don't place a heavy emphasis on psychological screening. >> if the screening is merely adequate and they're lumping psychological screening in with medical screening, is it possible to dupe the screener? >> absolutely. most psychological evaluations are simply a checklist. and a person will answer and the evaluator will look down to mark it on his paper, never looking to see what kind of body language maybe the person does that gives you a clue that there's some sort of stress or anxiety in answering a question. >> reporter: another problem,