( CNN ) So now we know . The Germanwings aircraft that crashed earlier this week was deliberately brought down by a co-pilot who had managed to lock himself in the cockpit as he set the plane on a course for destruction , according to officials . We all wish it were n't so , and the investigation , instead of looking at possible deficiencies of the plane , will now look to the co-pilot , who -- by all accounts -- showed no signs that this would be his horrific legacy . The irony would be rich , if it were n't so tragic . The locked door , the very mechanism put into place to protect the cockpit from unruly or dangerous passengers -- made more secure in response to the September 11 , 2001 , terrorist attacks -- was used against a pilot who , for reasons still unknown , left the cockpit . It may be too early to draw conclusive lessons from what has happened , but as this unfolds and before we begin constructing a narrative about the pilot that may be filled with rumors , innuendo and half-truths , there are structural issues to address immediately . First , we have seen that there is a real risk of pilots bringing down planes . We have built no back-up plans into the secure cockpit programs . It might be necessary to devise secure and classified entry access passwords or electronic keys that are available only to both pilots or a pilot and the lead flight attendant . No system of security should rely on a single point of entry and while the post-9/11 security planning made sense then , it may have outlived the threat now . Second , regardless of pilots ' backgrounds and ideologies , airlines as sophisticated as Lufthansa may need to implement more than voluntary stress-relief assessments . The zeitgeist of pilots is very similar to the military : tough , strong , with psychological challenges viewed as `` sissy . '' Perhaps airlines will need to guarantee that pilots who seek counseling will not be unjustly punished . And instead of sitting back and waiting for someone to approach counselors , regular and consistent check-ins might be necessary . Finally , the `` t '' word . Before the news today , the Obama administration quickly rejected a notion that this was terrorism . And that may still be accurate . But as someone who has been a part of counterterrorism efforts , I am impressed with the French prosecutor 's honesty in a search for the right words . This is obviously terrorism in the general sense to elicit fear in a general population , but whether it was done for some political or ideological reason ( in the absence of any group taking credit , it does not fit the model of most major airline terror attacks ) we still do not know . And it is n't as if there is a national response that we can expect from Germany , such as going to war . Still , it clearly is n't just suicide . This is different . If there is some nefarious ideological motivation , this may be one of a few incidents where a `` loner '' is able to create massive , simultaneous deaths . Most lone wolf terror is almost always of low consequence . It may be that we are in an era when we do n't have the right words to describe the threats we face from loners with the capacity for mass casualties . As Lufthansa CEO Carsten Spohr said , `` If a person kills himself and also 149 other people , another word should be used -- not suicide . '' And that honest assessment is what we heard today .
Juliette Kayyem : Now we know co - pilot brought down Germanwings safely ; this shows need for structural changes to post 9 - 11 security . She ##wing airlines will explore new ways to allow secure access to cockpits ; better evaluate safety of pilots ; consider what is ` ` terror ''