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How Many Weeks From a Practical Test
Turn hours flown, lessons per week and your local examiner wait into a date you can actually defend to a student.
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What One Hour of Dual Actually Leaves You
Put the wet rate, the real hourly costs and the unpaid briefing time in one place and see what stays behind.
Most posted rates at small flight schools were set by looking sideways at the field next door. That works until fuel moves fifty cents, an engine reserve gets honest, or an instructor asks for a raise, and then nobody can say whether the school is making money on dual or quietly subsidizing it out of the discovery flight column.
This calculator builds one hour from the bottom up. Fuel and hourly reserves, the fixed costs allocated per flight hour, instructor pay, and the brief and debrief minutes that get paid but never billed. The result is contribution per dual hour, which is the number that tells you whether volume will help you or hurt you.
Your result
Billed per dual hour
$250
What the student pays for one hour of dual instruction.
Cost to deliver that hour
$187
Includes the ground time you pay for and never invoice.
Left after costs
$63
Contribution toward the airplane note, the office and your own pay.
Share of the bill you keep
Margin as a share of the invoice, before taxes and weather downtime.
A dual hour that clears less than the cost of one unbilled ground hour is a rate problem, not a volume problem.
Where small schools underestimate the cost
The two costs that go missing most often are hourly reserves and unbilled ground time. Engine and propeller reserve is not optional money, it is a bill arriving later with a fixed date attached, and a school that skips it is borrowing from the overhaul. Ground time is worse, because it is real labor that both parties agreed not to name. Thirty five minutes of briefing and debriefing per lesson at instructor pay is a meaningful line at any volume.
The other quiet cost is the hundred hour inspection on any airplane used for hire with instruction provided. It arrives on a schedule set by flight hours, so it belongs in the hourly reserve rather than in the annual budget where it is easy to forget.
Using the number in a rate conversation
Contribution per dual hour is the number to bring to a partner, an aircraft owner on leaseback or a co-owner who wants to know why the rate moved. It converts a rate argument into an arithmetic conversation, and arithmetic ends faster.
It also tells you which lever to pull. If contribution is thin because fixed cost per hour is high, the answer is utilization, not price. If it is thin because instructor pay plus unbilled ground exceeds the instruction line, the answer is either billing ground properly or shortening the brief with better preparation between lessons.
Questions about this calculator
Should the instruction rate be in here if the CFI bills students directly?
If the instructor invoices the student independently, set instruction billed per hour to zero and set instructor pay to zero. The result then shows the aircraft side only, which is the right view for a school that rents wet and lets independent instructors bill their own time.
How do I estimate hourly reserves honestly?
Take the realistic overhaul cost for your engine and divide by the hours you expect to reach before it, then add propeller and hourly maintenance history from your own invoices. Most small operations find the honest number is higher than the one they had been using.
Does this account for weather cancellations?
Not directly, because this is a per hour view. Cancellations hit you through fixed cost per flight hour, so if your airplane flies fewer hours than planned, raise the fixed cost input and watch the contribution fall. That is the real cost of a weak winter.
More free tools and working documents
Working document
The Student File Audit Checklist
Work this list once per student per stage and no examiner will find a gap you did not already know about.
Now hold that number steady all semester
One run answers one situation, and then a week of low ceilings and an open squawk move every input again. PreflightLog carries the hours flown, the graded maneuvers and the endorsement dates forward on their own, so the answer is already there when a student asks in the runup area. Book a demo and we will run it against your actual schedule.