Maintenance is the one cost that you cannot predict. For a Cessna 172
type aircraft it is $5-$15 per hour. It will be more toward $15 if you
have a lot of instuments and radios as gyros, vacuumn pumps and radios
go out periodically. Don't forget prop/engine reserve at about $10 per
hour. It also depends on how much the plane is flown. The more it is
flown per month the lower the hourly maintenance.

The fixed costs, hangar, insurance, even annual can be predicted
fairly accurately.

And then you have to be able to put $10k into the plane at any random
moment in time due to something big failing, usually the engine, but
also could be an accident. So you need a reserve. Also, although
people rarely consider it, there are instrument, upholstry and paint
reserves, as these eventually need to be redone.

Andrew Gideon wrote in message gonline.com...
Barry wrote:

Our club has both dues and hourly rates, but we don't strictly allocate
fixed costs to dues - it's based more on what works out overall and what's
preceived
to be reasonable. We've also found that our maintenance costs per hour
depend on hours flown - or I guess you could say that maintenance has a
large fixed component that we're unwilling to allocate completely to dues.

Hmm. I don't suppose you've any numbers associated with this?

There is certainly at least one fixed cost maintenance component: the
annual. Aside from that, though, what? As I understand it - and I'm new
to all this, so take my understanding with a huge grain of salt - most
problems in active aircraft occur from use, as opposed to from time.

One other exceptional case is a recently acquired aircraft. Paramus bought
two about a year ago, and there was a fair bit of money spent on both
"maintenance" and "upgrades". The upgrades were considered part of the
capital investment, but the maintenance costs were not. I think that this
was wrong (some early maintenance should be considered part of the capital
cost) but we'll know better after a few years of use.

Of course, there is the idea that an aircraft not being flown is a waste
of
fixed costs. Is that what you mean?

Pretty much. In our system, this shows up as the cost per hour being too
high.

In theory, this just shows up for us as too few hours. If the cost per hour
is high, then there's a separate problem.

Part of the issue in the fixed vs. monthly costs for us is that there's no
distinction made in the monthy fees between a member that is, or is not,
qualified to fly a particular aircraft. More, there's no distinction made
between one that does or does not fly a particular aircraft.

Thus, the choice was made to have those flying the airplane pay for the
variable costs.

A similar argument could be made that the tach rate should cover *all*
costs, and I can see the point. But that would make rates less
predictable, which is considered undesirable.

Funny...when I joined I was far more interested in learning about
maintenance. But after discussions involving the numbers, I'm finding the
financial details strangely attractive grin.

- Andrew