Patrick gave his thoughts on the retirement of Concorde. I have some too, but first some background. (This post is actually mostly about the Concorde, but I am going to do a digression on aircraft safety before I get to my point).

The Airbus consortium was founded in the early 1970s, as an attempt to compete with the American companies (Boeing, Douglas, and to some extent Lockheed) which then dominated the commercial aircraft industry. Like the Franco-British Concorde consortium, Airbus was a multinational European consortium, which got launched with government money, although Airbus had the participation of Germany as well as Britain and France. The first Airbus Aircraft, the A300, made its first flight in late 1972, but for a few years Airbus had few customers except Air France, who were compelled to by Airbus aircraft by the French government.

However, as it turned out, the A300 was actually an excellent aircraft, and in one one respect was a long way ahead of the curve. It was the first wide bodied aircraft with only two engines. In terms of fuel economy, this arrangement is superior to using three or four engines, and the aviation world eventually woke up to this, to the extent that most new widebody jets sold now have two engines.

(Digression: In aviation speak, a "wide bodied" aircraft is one with two aisles inside the cabin and that therefore carries seven or more passengers in each row. The Boeing 747, 767 and 777, the McDonnell Douglas DC-10 and MD-11, the Lockheed L-1011, the Airbus A300, A310, A330, A340 and forthcoming A380, and the (Russian) Ilyushin IL-86 and IL-96 are widebodies. All other passenger aircraft are narrow bodies and have a single aisle).

Airbus eventually managed to get some A300s in service in the US by essentially loaning a few for free to Eastern Airlines. Eastern figured out quite quickly that they were an excellent aircraft, and orders for the aircraft (and the A310, a smaller version of the same plane) eventually got going in the late 1970s). Still, though, Airbus was a niche players, as most aircraft sold were narrow bodies, and this sector of the market was dominated by Boeing's 727 and 737, and McDonnell Douglas' MD-80.

Airbus, with a great deal more European government money, was determined to enter this market segment. It developed a new aircraft called the A320, which was around the same size as the 727 and MD-80. Airbus again attempted to be ahead of the curve, by producing the first passenger jet that used what is known as "fly by wire". All previous aircraft had direct hydraulic connections from the controls to the control surfaces of the aircraft. The A320 instead has a computer that controls the aircraft, and the pilot essentially operates the computer through a set of controls that include a "sidestick", something like a computer game joystick. Airbus promoted this aircraft is being somewhat safer than previous designs, because if the pilot did something silly he could be overruled by the computer. Which was great. Airbus received a substantial number of orders for the new type, and it went into production.

When the A320 was a brand new type, Airbus demonstrated it at the Paris Airshow in 1988, and managed to crash one of the first examples in a demonstration of the aircraft. Airbus management were rather eager to blame the crash on "pilot error", after previously promoting the fact that the aircraft was rather more immune to "pilot error" than previous aircraft. Another A320 crashed in Bangalore, India, in 1990, and a third in France 1992. All were what is euphemistically called controlled flights into terrain.

The question that arose at this point was whether there was anything wrong with the fly by wire system. Investigations occurred, and training of pilots for the A320 was changed a little as a result. There was nothing fundamentally wrong with the aircraft, but it seemed some miscalculations were made at the beginning of its time in service. Airlines continued to order it in large numbers, at least partly because Boeing retired its 727 without producing a proper replacement. There are now around 2000 of the aircraft in service, most of them flying four or five (or more) flights a day.

Personally, in 1993 I was concerned about the safety of this type of aircraft. The fact that there had been several similar accidents was a concern, and I wasn't sure whether fly by wire for passenger aircraft was a good idea. Accidents aren't caused solely by pilots, but are generally caused by a mixture of factors, one of which is the quality of the user interface. Given the crashes, there were inevitably doubts about the user interface.

However, when you have 2000 aircraft flying every day, you can do very accurate statistical analyses about how safe they are. And the number of subsequent A320 crashes has been small. We can say with something close to certainty that the A320 is a very safe aircraft, even though this may once have appeared not to be the case. If the aircraft appeared unsafe originally, this was either a statistical fluke, or the problems that caused this were fixed. From the worst possible way of looking at it, the aircraft had been flown enough and tested enough to get the bugs out. The number of aircraft in service also allows the cost of a safety effort to be spread around a large number of customers, which adds relatively little to the costs of each of them.

Now, however, look at the Concorde. Only 14 of them ever went into airline service. The number of routes they operated on was small, and six aircraft could have handled those routes pretty easily. Therefore, the number of flying hours per aircraft was very small. While the aircraft have either equalled or exceeded their expected life in terms of years, they are absolutely nowhere near their expected lives in terms of flying hours (which is probably the more important of the two issues).

And as everyone knows, a Concorde crashed in Paris in 2000. Suddenly, there were doubts about the aircraft's safety. My first reaction was that the type would never fly passengers again. The reason for this was essentially a variant of the above discussion of the A320. In terms of flying hours per accident, the Concorde suddenly had a far worse record by far than any other type of aircraft. This could have been a statistical fluke, but it probably wasn't. However, we didn't have enough data to tell. Investigators found the direct cause of that particular accident, but aircraft accidents are usually caused by a mixture of factors, and even if that particular problem was fixed, the fact that a crash had occurred suggested that even though the aircraft had been in service for nearly 30 years, it actually hadn't been flown enough to get the bugs out. This was made worse by the fact that the Concorde is a supersonic aircraft (although it wasn't being flown supersonically when it crashed) as this meant it was likely to have an entirely different set of bugs to subsonic aircraft.

Air France and British Airways did what they were asked to get the Concorde back in service, and at the time this may have appeared to make financial sense due to the fact that we were at the tail end of the bubble and City type people were still prepared to pay to fly Concorde. (Plus of course it was a matter of pride). However, sensitive to the types of arguments I have given above, I think it is likely that safety regulators demanded that the aircraft receive much more maintenance and much more monitoring for other potential safety concerns than was the case before the crash. This Reuters article says that operating costs had surged 58 percent since the crash. One needs to strip out changes in fuel costs to really understand what this means, but my suspicion is that an increase in maintenance and safety compliance costs were a big factor in all this. There is also probably a gradual increase in other maintenance costs due to the simple age of the aircraft - fewer and fewer of its spare parts are readily available and have to be made specially. I don't know if this is as bad as NASA buying parts for the space shuttle on ebay, but even so there must be a gradual increase in costs of running the Concorde for this reason too, although one does not expect this to be responsible for a sudden jump in the costs of running the Concorde as was the Paris crash. Basically, BA and Air France were being much too optimistic when they decided to get Concorde flying again after the crash.

And we now have the economic slump in the financial services sector. It looks extravagant to have executives flying Concorde when they are simultaneously sacking lots of people, so the number of people flying Concorde has dropped. Because of the reasons given above, the load factors needed to make Concorde profitable have increased considerably at the same time load factors are dropping, and it is much hurder for BA and Air France to hold out until the end of the recession. There have been flights cancelled recently, and this may be due to much more stringent safety requirements than those that existed before the crafh. When the recession ends, the factors to do with the aging of the aircraft will make operating costs even worse than they are now, so there is little point in mothballing the aircraft with the thought of bringing them back later.

Some of the safety and spare part costs are fixed regardless of the number of aircraft, so if British Airways stop flying the Concorde, on a per aircraft basis they increase further if Air France keeps flying. Therefore, when one airline decided to stop flying Concorde, the other was pretty much compelled to do so also. This also makes it very hard for one or two airlines to be kept around for charters. Which leads us to where we are today. The Concorde was a beautiful anachronism. But an anachronism it was, and this has finally caught up with it.

(A reasonable amount of the above is supposition. If we have any readers who know the actual details, I would be interested to hear tham).