Apart from trying to find out the motivations, the debate on the past week’s tragedy in which over 150 people were killed by the pilot who should have been taking care of them has centred on why Europe has not adopted the US standard of requiring two crew members in a cockpit.

The argument can be made that the US has been overly security conscious since the September 11 terrorist attacks. The rigours of getting through a US airport, especially for international arrivals, is testament to that. But the plus side has been no plane-related attack on US soil since 3,000 people lost their lives in the Twin Towers collapse.

There is also another argument: while certain security measures can be seen as too onerous on the vital process of travel, can the same be said for the two-person cockpit rule? No is the simple answer since all it requires is a flight steward to take a little time out while one of the pilots needs to leave to cockpit. That’s not onerous at all.

Which is what made Lufthansa’s insensitive and arrogant initial reaction to the question all the more surprising. The airline’s CEO initially said he saw no need to implement any change to existing practice before being forced into an embarrassing climb-down the following day after derision at his very misplaced comments. His remarks were not just foolish. They were a slap in the face to the families of those who lost their lives in the most cruel circumstances a few days earlier. The passengers on the ill-fated Germanwings flight from Barcelona to Dusseldorf did not perish due to a catastrophic mechanical failure but because of the mental condition of one man who was unfortunately at the controls.

Could this have been avoided by having another person in the cockpit when the captain left the flight deck to visit the toilet? One cannot say so definitively, but it would have made the outcome less likely. Why did the American authorities foresee this scenario while most European airlines did not?

Thankfully, this horrific act – whereby Andreas Lubitz intentionally put the aircraft into descent while ensuring the captain was locked out of the cockpit – is extremely rare. But the fact that the very possibility exists makes it necessary to guard against it.

Screening of pilots also needs to be improved. Mr Lubitz was not known to have any links to extremism or terrorism but reports have emerged showing he suffered from depression, which hampered his ability to qualify and prevented him from making it to the rank of captain.

More shocking news has emerged that German prosecutors said Lubitz was given a sick note from doctors showing he suffered a health condition which would have prevented him flying the day of the crash, which he apparently hid from his employer.

Lufthansa said that while it conducts regular medical examinations on its pilots to ensure they are fit to fly, it does not carry out psychological tests. This policy will have to change and the international aviation authorities should make it mandatory. Indeed, the European Commission should take the lead.

The fact that doctors were treating Mr Lubitz for what is believed to be a mental illness also raises questions about the responsibility of the medical profession in such a situation. In normal circumstances there is such a thing as doctor-patient confidentiality, but, knowing that Mr Lubitz was a pilot, a discussion needs to be held on whether in future doctors in this situation should inform the employers about their employee’s condition.

We will never be able to fully prevent incidents of this nature. But, with less arrogance and common sense, we can go a long way to ensuring they become even more unlikely.