Hello!
With mogas shooting sky high some estimates for 2010 of £1.20 per litre for cheap unleaded what on earth will AVgas hit?
I have been to places in Italy where Avgas is sold for 2,60 Euros per Litre already now. At the typical consumption of a C421 of 230 lbs/hr (twice that during climb...) the fuel alone costs 370 Euros per hour. And with five or even six people on board (*) you need to refuel on the return flight. Every time!
But the biggest problem (for me) with vintage piston twins is the availability of spares. A '421 that I used to fly was grounded for almost six months because there was no spare oil pump to be found anywhere. And when they found one, it cost over 5.000 Euros. Because it was the only spare oil pump for a Continental GTSIO 520 worldwide at that time. Next time, they will ask 10.000 Euros for one. Or twenty. Simply because somebody will pay for sheer frustration. You cannot base a commercial operation on anything like that. If your aircraft is grounded for technical reasons, it must be back in the air within a couple of days. Otherwise you lose your customers.
Greetings, Max
(*) Interestingly, the smaller and cheaper the aircraft, the more passengers will be inside (watch next time when you are on a GA apron). Customers who charter a piston twin because that's all they can afford will always come with as many people as there are seats. Because they pay for it and they don't want to lose those seats they pay for. Thats also why you always operate piston twins at (or above) MTOM with absoultely no performance reserve.