Every dollar figure on a flight row is one of two things: a real amount from a record we hold, labeled Documented cost, or a modeled estimate of air hours times an hourly rate, shown as a range. This page covers where the rates come from, how wrong they can be, and where we refuse to put a number at all.
Where the rates come from
782 priced public-record lines totaling $5.00M: state aeronautics billing logs, charter invoices, foundation reimbursements, payment postings, and booster gift valuations. Those are not all interchangeable. Charter estimates are fit only from paid invoices and reimbursements that can be tied to a complete flight outing. State billing tests owned-aircraft recharge rates; gift valuations and payment postings remain source evidence but do not train charter rates. Where we hold the actual invoice for a trip, the row shows that amount tagged Documented cost and the estimate steps aside. How we get the records: how we source flight records.
Owned, chartered, booster
For charter, we first look for paid outings from the same operator and aircraft type. If none exist, we widen the comparison in steps: aircraft type, operator and aircraft class, then aircraft class. Only after those receipt cohorts fail do we use published market rates. Receipt totals are already all-in, including fuel, so we do not add fuel or federal excise tax a second time. The estimated fuel usage shown on a flight report is separate operating context, not another charge added to the dollar estimate. Older payments are normalized to the flight date with the same aviation-cost index used by the fallback model. A university-owned aircraft has no bill, so we compute two numbers and show both: marginal operating cost (fuel, maintenance, reserves: what the flight added) and allocated operating cost (marginal cost plus the annual fixed operating burden the selected source establishes, spread across stated utilization scenarios). The current catalog does not consistently establish depreciation or cost of capital, so we do not label that scenario full economic cost. Which of the two we headline depends on which one the evidence supports. Where an operating agency publishes a recharge rate and its billing records let us test the model against real transactions (state-pool turboprops), the headline is that billed basis, because it is the only owned figure any transaction has validated, and the allocated number is listed beside it. For owned jets no such record exists, so the headline stays the allocated estimate and it is notvalidated against any individual trip: it is a model of what the ownership costs, not a bill anyone received. A booster’s airplane is neither: its rows show an estimated valueof the flight as gift-in-kind context, and that value is never added to a program’s spend.
How wrong it is
We refit the model on state billing records dated before 2024, then scored it on 2024 legs it had never seen. The published band contained the real billed amount for 85.4% of those flights (129 of 151); the median midpoint missed by 22.6%, so trust the band, not its midpoint. That holdout is turboprop state-pool billing from one state: a real test of the method, not a measurement of jet accuracy. The best owned-fleet anchor is Tennessee, which publishes its own totals: $3.29M across 647.3 hours, $5,084/hour in allocated operating expenditures. The Tennessee-specific row is anchored to that published total; it is a reconciliation check, not independent validation.
Because that validation covers turboprops only, an owned jet with no institutional cost record is modeled from the specific aircraft type’s variable hourly cost and annual fixed burden. The low, midpoint and high cases allocate those fixed costs across 450, 325 and 200 annual hours, respectively, while carrying the operating-cost catalog’s stated uncertainty. A published school- or aircraft-specific rate takes priority over this fallback. These utilization cases make the largest unknown explicit, but they are not jet-invoice validation.
Charter coverage is still uneven. A receipt-backed estimate requires at least three independent paid transactions; thinner cohorts fall back to class-wide or published market rates. Every flight report names the basis and comparable count. Where a class has at least three paid outings of its own, the class-wide rate is re-centered on what those outings actually cost per hour, so a class-level figure is the same number as a type-level one with a wider band rather than a different, lower one.
Where it is not (a published market rate and nothing else), the midpoint is a floor, not a quote. It prices observed air time and nothing else: customer-paid positioning, daily minimums, airport and FBO fees, crew overnights, deicing, catering and trip support are all real charges we cannot see. Across 16 documented charter outings, the amount actually paid ran a median of 1.1× and as much as 3.0× that floor. So the top of a market-rate range carries 2.37× the midpoint, the 90th percentile of those observations, and the range is deliberately lopsided. Read the midpoint as the least the flight can have cost.
For a standard domestic charter fallback, federal tax is modeled at the IRS rate effective on the flight date. The segment tax is per passenger per taxable segment. When no passenger count is documented, the estimate uses a disclosed one-passenger minimum; it does not infer a manifest. Rural-airport exemptions and fractional-program fuel-surtax treatment are not inferred; either requires source-specific support.
What these numbers do not claim
- Nothing about who was aboard or why. Cost is arithmetic on hours and rates, never evidence of purpose or passengers; those claims are governed by our editorial policy.
- No annual total is ever split into a flight list.A vendor’s yearly total from a tax filing sanity-checks an aggregate; it is never divided across trips we cannot tie to it.
- Some attribution is provisional.Trips matched through an aircraft’s present-day owner say so in their breakdown and will shift as effective-dated ownership fills in.
- An unpriced flight shows nothing. No established aircraft class or usable duration, no dollar figure.
If you hold a record that contradicts a figure here, we want it: see corrections.