Part of that of course because they are - they have got a lot of moving parts, they work in very difficult environment, very hot, so really engines are a very different issue from the airframe. The airframes are, you know, harder to inspect and that is why it is important that the inspection program is put in place by the manufacturer. Anecdotally it may be worth, just for background, recognising that in the late 80s, 747s had a much bigger problem than this one with the 767 in terms of a cracking around the nose area around by the front door where the first class passengers get on. And, I mean, it was not a question of grounding 747s at that stage, but it was a question of putting in a process, and that process is actually a complete rebuild of the nose section of a 747 which is undertaken by all the old 747s when they come up to a certain number of take-offs and landings. There is a history of a very similar occurrence but a much more significant one.
All aircraft are fatigue tested by the manufacturers and they have a life.
It is significantly higher than anything we are talking about here. I do not know if you recall Hawaiian Airlines had a 737 where literally the whole of the top skin ripped off and it ended up looking a bit like a convertible. And this would have been about 1987 I guess, and that really first brought to the fore the fact that some aircraft aged a lot more quickly than others, and that is an issue of what people do with it. I mean, Hawaiian, they are sort of wandering between the islands and they are going up down, up down all the time and this was putting a pressure on the aircraft that the designers had never anticipated. And it did give us the opportunity to start as an industry recognising that aging aircraft is an issue and there have been a number of major studies of the whole area of aging aircraft since then.