PPRuNe Forums - View Single Post - EC-225 orders hot up
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Old 14th Mar 2007, 11:15
  #42 (permalink)  
HeliComparator
 
Join Date: Aug 2004
Location: Aberdeen
Age: 67
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simfly

Of course the 225 has had some technical issues, as has the 92 in service with other operators and soon with BHL. Because manufacturers don't test their aircraft properly, its a sad but well-known fact that new helicopters always come with problems and will certainly be initially less reliable than those they replace. Its the bathtub theory - ie take a section longways through a bathtub so see the shape of the reliability graph. Crap at first, but then steeply improving to bottom out for a long time, before aging aircarft syndrome starts to cause failure rates to creep up again. I would say the 332 is just starting to creep up the back of the curve whilst the 225 and 92 are very much in the middle of the downward slope.

I am not sure if the oil companies understand this - they certainly like to complain at every glitch. But it has to be that way (until manufacturers do more maturity flying) as otherwise you never replace your aircraft and they slowly die on their feet.

What this debate has really been about is the different design approaches followed by Sikorsky and Eurocopter. Once intial reliability and spares issues are addressed, you will be left with two fairly reliable aircraft but which are completely different in design concept, and that is what I have been talking about.

Yes, the 92 is intrinsically rougher than the 332L even when flown at the same speed, however its active anti-vibration system does generate spheres of acceptable vibration in the cabin, but unfortunately also zones where the vibration is bad. So it just depends on where you sit. For the structure outside the cabin though, it has to put up with the stress.

HC
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