The circumstances are almost too horrible to contemplate. One of the pilots left the cockpit of the doomed Germanwings flight 4U9525 from Barcelona to Dusseldorf on Tuesday, leaving the other pilot alone. Even before 9/11 when four airliners were hijacked, cockpit doors had been strengthened. Following the US attacks, they became effectively impenetrable. This it seems was what contributed to Tuesday tragedy. It is being reported that the pilot who left the cockpit could not get back in. Despite increasingly frantic knocking, the other pilot did not respond. In eight minutes, the aircraft had plunged from it cruising height into the side if a French Alpine mountain and 150 people were dead. There are a number of issues which will need to be addressed as the inquiry progresses. One is why the security keypad override on the door could not be activated by the pilot outside. Did he forget the closely-guarded number or had the keypad been deactivated from inside the cockpit? If the latter, then it will suggest a horrific suicide by the pilot who remained at the controls. At least investigators have a great deal of evidence to go on in this latest crash. Though the aircraft was smashed to smithereens, it can still be reconstructed notionally. Since it already seems likely that there was no catastrophic failure of the fuselage, the focus will be on the cabin door and the security access pad. But there are also now questions about the safety of the Airbus A320, a medium haul workhorse used by airlines round the world. Last December an AirAsia flight crashed in the Java Sea in circumstances which have not yet been explained. It had apparently flown into bad weather, which was not the issue with this week's Germanwings disaster. The loss of Malaysian Airlines flight MH370 is, of course, the more disturbing because no trace of the airliner, a Boeing 777, has ever been found. Without even the smallest scrap of evidence, save inadequate tracking of the flight's errant course, investigators have absolutely nothing to go on. Mile for passenger mile, flying remains by far and away the safest form of transport. However, the statistic is inherently misleading. A single aircraft will travel many more miles than a car or train. There are, however, far less aircraft than there are trains and certainly motorcars. So when there are a number of plane losses close together, even the most seasoned flyer has the right to wonder if there is not perhaps something wrong. Some flight analysts will tell you that there is indeed a problem. Ever since the Wright Brothers first flight in 1903, aircraft technology and design has advanced at a dizzying pace, impelled by the demands of wartime and space travel. Modern aircraft are highly complex machines. However, with complexity comes risk. Computers are needed to help control a modern airliner, to say nothing of a superfast warplane. Such is the speed of change in advanced air forces, that it is now clear that the next generation of fighter aircraft will have no pilots at all. Moreover, there is now extensive replacement of metal with lightweight composite materials. Of course, these are all tested, but as the Boeing 787 Dreamliner battery fires make clear, the stability of brand new technology is always going to be an issue.
