Most owners know roughly what fuel costs. Far fewer know what their airplane costs per hour once insurance, hangar, the annual and the surprise cylinder are counted. Good expense tracking turns a pile of receipts into a number you can use to set a rental rate, split a partnership fairly or decide whether to keep the plane.

Two kinds of cost

Every aircraft expense is one of two kinds, and keeping them apart is what makes cost per hour useful.

Fixed costs

You pay these whether the plane flies or not: hangar or tie-down, insurance, the annual inspection, loan payments, database and subscription fees. They're usually recurring, so you can enter them once with a schedule.

Spread across the hours you fly, fixed costs fall as you fly more. That's why an airplane flown 50 hours a year costs far more per hour than the same airplane flown 150.

Variable costs

These rise with every hour: fuel, oil, routine maintenance, and the reserves you set aside for the engine and propeller. They're roughly the same per hour no matter how much you fly.

For a detailed breakdown of what goes in each, see how much it costs to own a plane.

Categories that work

Use few enough categories that you'll actually use them, and enough to answer the questions you'll ask later:

  • Fuel
  • Oil
  • Maintenance and repairs (squawks, parts, labor)
  • Inspections (annual, 100-hour, ELT, transponder)
  • Hangar or tie-down
  • Insurance
  • Financing (loan payments, interest)
  • Avionics and subscriptions (database updates, ADS-B service, apps)
  • Fees (landing, ramp, parking, FBO charges)
  • Other

Tie each expense to the aircraft, not to the person who paid. If a partner buys fuel on a trip, it's still the airplane's fuel.

Receipts

Attach the receipt to the expense when you enter it, not later. It answers partner questions, supports insurance claims and helps whoever prepares your taxes. A photo on your phone is enough.

Keep maintenance invoices with the maintenance records too. A buyer will want to see them, and they back up the logbook entries.

Getting to cost per hour

Cost per hour is total cost over a period divided by the hours flown in that period:

(fixed costs + variable costs) ÷ hours flown

Use a long enough period to smooth out lumpy bills. A three-month window that happens to include the annual will look alarming; twelve months is more honest. Decide which meter you're counting, Hobbs or tach, and stick to it.

Want a quick estimate before you have a year of data? Try the aircraft cost per hour calculator.

Splitting costs in a partnership

Most partnerships split costs two ways:

  • Fixed costs are shared equally (or by ownership share), usually as monthly dues.
  • Variable costs are paid per hour flown, at a wet hourly rate that covers fuel, oil and reserves, or dry plus the fuel each partner buys.

This only works if every flight's hours are recorded and every expense lands against the aircraft. Write the method into your partnership agreement, and review the hourly rate once a year against actual costs.

Common mistakes

  • Forgetting reserves. Engine overhaul is a real cost per hour even if you won't pay it for years.
  • Counting only the fuel you bought at home. Trip fuel is often the biggest line.
  • Mixing aircraft with personal spending on one card without labeling it.
  • Updating once a year. By then nobody remembers what the $340 invoice was for.

Frequently asked questions

What is a good way to track aircraft expenses?

Record each expense against the aircraft as it happens, with a category and a receipt photo, and record the meter readings for every flight. With both, you can calculate cost per hour for any period. Aircraft expense tracking software does the math for you; a spreadsheet works if you keep it current.

What is the difference between fixed and variable aircraft costs?

Fixed costs, such as hangar, insurance and the annual, don't depend on how much you fly. Variable costs, such as fuel, oil and maintenance reserves, go up with every hour flown.

How do I calculate my aircraft's cost per hour?

Add up all costs for a period, ideally 12 months, and divide by the hours flown in that period. Splitting the result into fixed per hour and variable per hour shows how much flying more would lower your cost.