Ben, thank you for an attractive and easy-to-use spreadsheet.
Spreadsheets aren't hard to make; but they're hard to make user-friendly to
others.

Since you pre-plugged some numbers for a model I'm considering, let's
discuss how realistic they are for a Cherokee 140:

Fixed Costs/year
Insurance 1,500
Tie-Down 900 (at my airport)
Annual 1,200 ("minimal surprizes" for 100 hours?)
Total Fixed 3,600

Hourly Costs
Fuel 23.31 (7.9g/h x 2.95/gal)
Overhaul 10.00 ($20,000 / 2,000 hours; engine overhual only, not
prop)
Reserve 15.00
Total Hourly 48.31

At 100 hours/year that's $4,831 + $3,600 = $8,431, plus the capital and
opportunity costs of buying it.
Opinions?


"xyzzy" wrote in message
...
Ben Jackson wrote:

For a long time I've been meaning to convert my cost of ownership
spreadsheet into a web page. Over the weekend I wrote a rudimentary
sc-to-html converter (sc is an ancient, terminal based spreadsheet).

http://ben.com/flying/costown.html

I've already filled the page with caveats and disclaimers in
anticipation
of the tough rec.aviation audience. Constructive criticism welcome...


This is great. I've been working on my own spreadsheet (who hasn't
and have some suggestions:

Breakeven hours are cited as tach hours. I think most renters only
think in terms of hobbes (elapsed time) hours and it took me a bit to
realize that when looking at the results. After all when I look in my
logbook to see if I'm flying enough to justify it, my logged time is
hobbes hours. You might want to consider adding an entry for "breakeven
hobbes hours" just to make it clear.

An "annual total cost for the renter" entry would be nice so renters
could see that number as a total in one place, as is done for the
owners. It's one thing to see the owner's annual total as $9047, wow
that's a big nut to crack, but when I compute my renter's annual total
from the spreadsheet's assumptions it comes to $5340 and suddenly the
annual premium, while still significant, doesn't seem quite as
intimidating.

Also, consider figuring in club dues to the hourly cost of renting. Do
you figure them into the breakeven point?

Also maybe different insurance entries for renters and owners. Looks
like you're assuming insurance for a renter is $0 (and it is in my club,
which insures all members) but many renters purchase renter's insurance
which is cheaper than owners' but is a cost they should figure in.

I know you suggested adding opportunity cost to the Annual entry, but
why not go ahead and have an entry for that, so people with loans can
put in their monthly payment.

It's the start of a great tool. I hope you will continue to maintain it.