The news that an airliner landed on half an engine drew some well-merited applause for the guts and skill of the pilots. It also awakened some slumbering anxieties. On the whole while joining in the applause I was rather on the side of the reader who wrote to the Post suggesting that it might have been a good idea to head for the nearest airport when engine trouble first blew up, soon after leaving Jakarta. This incident will no doubt be the subject of a detailed inquiry and we may find that the real story is less controversial.
Speaking in general, though, it is well known in the industry that the days when no self-respecting airline would send up a plane which was not fully functional are well behind us. Nowadays many systems are duplicated for safety reasons. But if there are four gadgets, each capable of doing the job on its own, there are obvious economies to be had from not being too officious in replacing them when they go on the blink. Airliners are expensive and need to be working to earn their keep. A few months ago I did a long and uncomfortable flight in a section of the aircraft in which the reading lights were not working. This is of course not a safety hazard, but the seat belt lights were not working either. This sort of thing leaves you wondering which of the parts you can’t see have also been “returned to service for evaluation” as the euphemism goes.
Another change over the years concerns the matter of having spare engines. Now of course airliners did not have four engines to provide a spare. They had four because they needed that much puff to get off the ground. But having got off the ground they could fly comfortably on three engines, less comfortably on two — depending on which two it was — and in an emergency they could limp along on one. Because of this safety feature it used to be a requirement that airliners on long distance flights — especially over water — should be four-engined types. This has gradually been corroded and now seems to have disappeared completely. Engines are, I suppose, much more reliable than they were. Still, if you are a long way from home on two engines clearly the failure of one is a very serious matter and most of us, under these circumstances, would wish to be delivered to the nearest railway station rather than participating in an epic further journey.
The mention of railways brings me to an interesting oddity. I am an eager reader of disaster accounts of all kinds. The stories of accidents combine technical and human interest in a compelling way. Simplifying a bit, we can say that in the 19th century the interesting accidents are on the railways, in the 20th they involve aeroplanes. But there is another difference. In the railway accidents the inspectors were robustly critical of any part of the arrangements which did not seem to them to be conducive to safety. Managements were vigourously badgered to adopt improvements like air brakes and automatic train control to improve the safety of their operations. The people who investigate air accidents seem to be less inclined to include the management in their area of operations. Accidents are attrributed to obscure technical deficiencies, blamed on the weather or ascribed to error by the pilots, who are often not there to defend themselves. It is a common observation that some airlines have a lot more accidents than others, which seems to suggest that something more systematic than the fickle finger of fate is involved. But this is rarely discussed in public. Instead we get used to it. There was another air crash in Indonesia the other day. Didn’t even make the front pages.
tim's experiment 
It is general belief that outsourcing of aircraft maintenance has increased the risk of engine failures. A classic example is the Qantas Airways which has contracted out its aircraft maintenace to Malaysia. Before outsourcing, Qantas was the most reliable and safe airline but after, all sorts of breakdowns and faults have emerged. It has been reported that Cathay Pacific has also outsourced its maintenance to Malaysia on economic grounds.
Indeed. I have a suspicion that what is going on here is rather like those studies of driver behaviour which find that as cars get safer people simply go faster. Drivers have a desired level of risk and if you remove it in one place they put more in somewhere else. Where airlines are concerned this means that if the equipment gets safer in some ways then they can save money by skimping on maintenance and still provide what they doubtless consider “acceptable” levels of risk. Unlike car drivers, though, they are risking other people’s lives rather than their own. Recently we had the interesting spectacle of European airline chiefs complaining that they were not allowed to experiment with the effects of volcanic ash by flying plane loads of passengers through it. That would have been an exciting flight.