" None the less, age doesn't matter when it comes to aircraft.. Its all about the maintenance."
This is utter nonsense. Nothing is forever and increased age means increase aging aircraft checks, parts that on a newer aircraft would not have to be replaced, being replaced due to fatigue/corrosion, and at the end of the day, higher costs. It's not for nothing that aged aircraft are comparatively cheap on the market.
Another factor is that as an aircraft ages, it gains weight. Patches, repairs, modifications, etc. The weight creeps up. The result is felt on the bottom line: less useful load, higher fuel consumption, etc.
Air Canada looked into the possibility of rebuilding its DC-9s instead of going for A319s and concluded it was economically unfeasible.
And I speak from experience. I own a 25 year-old Beechcraft with over 10,000 hours on the airframe (high for a light aircraft). I bought it cheap, but in the knowledge that I would have to pour money into it over the long run.
For example, I have a minor corrosion problem with the aircraft floor that has to be fixed within a year or so if it's not to become a major problem. It's repairable though. It comes from people's wet shoes dripping onto the floor for 25 years.
Now, multiply the hours on my Beech by 80-100. Add the stress-strain of repeated cycles of takeoff, pressurization, and landing. Leaking lavs, fraying wires, and other issues. It should be obvious that age DOES matter, though I agree with fine maintenance, an elderly aircraft can be safe, but it won't be as cheap to maintain as a newer one. Up to the bean counters to determine if the cost of patching an older bird is more economical than leasing a new one. Different airlines have come to different conclusions with, for example, the DC-9 (AC and NW
, and don't give me the "but AC
is bankrupt so they're a bad example" crap, they're bankrupt under a mountain of debt from an unwise acquisition of Canadian).
Finally, even with the best of maintenance, tops and sides come do off aging aircraft (Aloha 737, United B747). No matter how consciencious the maintenance, the more problems there are, the more likely a crack here or a spot of corrosion there will be missed and result in an incident.
Used airliners are cheaper for a reason...