The Aircraft Ledger / TailCheck
The seller flew it for years. You get one afternoon.
TailCheck reads a jet's own flight record, grades it against every aircraft of its type, and tells you exactly what to ask before you commit.
Gulfstream G650. Data current to 29 Aug 2026.
A hard-worked G650 that works from easy airfields.
Gentler than its type on engines and brakes, harsher on utilization, typical on fatigue and corrosion.
They know this aircraft. You're reading their summary of it.
Every used jet sale starts lopsided. One side has lived with the aircraft for years. The other gets whatever that side chooses to write down.
What the seller knows
Years of living with it
- Every trip it has flown, and where it spent the night
- How many of those trips were short hops, and how many landings that meant
- Whether it lived by the sea or in dry inland air
- The runways it used, and how hot and high they ran
- How hard it was worked, month after month
- Why it sat at a service center for four weeks last winter
What you're handed
One afternoon and a data room
- A spec sheet the seller wrote
- A total-hours figure
- One inspection window, booked around their calendar
Total hours tell you how much it flew. Nothing in that pack tells you how hard.
So the questions that matter get asked late: at the inspection, or after the wire has cleared, when an answer costs you money instead of giving you leverage.
Four questions the spec sheet can't answer.
TailCheck answers each one in its own chapter. Each is graded gentler, typical or harsher than the middle half of the aircraft's own type.
How hard has every landing been on the structure?
Each landing and pressurization cycle costs the airframe. Lots of short hops cost more than the hours suggest.
Sample G650Typical2.3 hr per landing, 32nd percentile
What has the air been doing to it overnight?
Where an aircraft sleeps matters. We place each night at a field and read the weather there.
Sample G650Typical6% coastal nights, 60th percentile
What have its departures asked of the engines, brakes and tires?
Short runways load the brakes. Thin, hot air works the engines harder on every takeoff.
Sample G650Gentler11% short runways, 17th percentile
How hard has it been worked, and did it ever disappear?
Steady private use and heavy charter-style flying look the same on a spec sheet. They are not the same aircraft.
Sample G650Harsher19.6 flights/mo, above the 99th percentile
Percentiles compare the aircraft with every tracked jet of its type. Typical is the 25th to 75th percentile.
What's inside a report.
The answer on the first page. Every figure behind it one click deeper. Read it in a minute, or spend an hour in the data; both are there.
A hard-worked G650 that works from easy airfields.
Gentler than its type on engines and brakes, harsher on utilization, typical on fatigue and corrosion, with one four-week stay away from base.
Beside it sits the airframe and window: registration, type, the 20-month window, 402 flights, tracking gaps, peer set and coverage.
Fatigue
TypicalFew very short hops and longer trips. Set by hours per landing.
Corrosion
TypicalDrier nights. Set by salt air.
Engines and brakes
GentlerEasy airfields and hot, high takeoffs. Set by short runways.
Utilization
HarsherHeavy use and one long stay away. Set by flights a month.
Each chapter opens with a one-line verdict and its three most telling figures. Nothing more until you ask for it.
| Measure | Below, median, above | This aircraft |
|---|---|---|
| Short runwaysLead measure. 17th percentile. | 11%middle G650 26% | |
| Hot, high takeoffs84th percentile. | 6%middle G650 2% | |
| Density altitude84th percentile. | 1,670 ftmiddle G650 1,150 ft | |
| Dust and dry climate64th percentile. | 10%middle G650 6% |
Every chapter has this table, with a note on any assumption behind it. Here: we assume the longest runway at each field, so short-runway figures are on the low side.
27days
Nov–Dec 2025
At a field with a Gulfstream OEM service center. Good tracking at the field throughout.
Ask for the logbook entries and work orders for that period. A scheduled inspection and an unscheduled repair look the same from the track.
of flights on one corridor
of flights on its three busiest pairs
42 flights crossed a border
Route shape only. Airports and exact dates are left out on purpose. An appendix adds its day-of-week and seasonal rhythm.
What it can show
- What it has flown, and where
- How hard it is used against similar aircraft
- Long stays on the ground, and the kind of place
- Where it spends its nights, and the weather there
What it cannot establish
- Mechanical condition, maintenance quality or airworthiness
- Exact hours and cycles, or flights we didn't see
- What work was done at any shop, or why it sat anywhere
- Whether it was hangared or parked outside
The full list runs to 11 limits. We'd rather you knew them before you rely on a figure.
Where it earns its fee, from shortlist to signature.
One report works at every stage of a deal, and it is most valuable before anyone has asked you for money.
- 1
The shortlist
Before you fly out to see anything
Three aircraft are on the market. Check each tail for free, then order reports on the ones worth your time.
You knowwhich one has been flown gently, before you've spent a day traveling.
- 2
The offer
Before the letter of intent
Write the offer knowing how the aircraft has really been used, not how the listing describes it.
You knowwhere it's harsher than its type before the seller has to tell you.
- 3
The inspection
Before the pre-purchase inspection starts
Hand the report to your technical team. Harsher on salt air? They look harder for corrosion. A long stay at a service center? They ask for those work orders first.
You getan inspection aimed at this aircraft, not a generic one.
- 4
The signature
Before the wire clears
Every open question has been asked while you still had leverage. Share the report with your lender or adviser by link.
You signon evidence, not impressions.
The record the aircraft kept itself.
Every jet broadcasts its position, the same signal air traffic control relies on. We read that record, not anyone's description of it.
Nobody involved in the sale has written a word of it. That's the point.
It isn't an inspection, an appraisal or a records review.
It tells you where to aim all three, and which records to ask for first.
- Graded against its own type
- A G650 is measured against G650s, never against a light jet. Typical means the middle half of that fleet.
- The middle aircraft, not the average
- Comparison figures are the 50th-percentile aircraft, so a few extreme outliers can't distort them.
- Thin evidence stays ungraded
- With fewer than 30 comparable aircraft, a measure isn't graded. You see it as context, not as a score it hasn't earned.
- Every count is a minimum
- Flights outside coverage are missed, and the report tells you how many: in the sample, about one flight in 7.
- Coverage you can check
- 20,348 aircraft across 49 types. Every type is measured across all its aircraft, in every region. Checking a tail is free, so you see the evidence before you pay.
Set beside the aircraft, a rounding error.
Every tail’s free record is open without an account. Pay for one report, or for every report you need.
Single report
For one aircraft you’re serious about.
$395one aircraft
- The full TailCheck report
- Open for three months, kept up to date
- PDF, CSV and a share link
- Paid once, no subscription
Unlimited
For brokers, dealers and buyers working several aircraft at once.
$995a month
- Every TailCheck report you need
- Spotlight, to put up to five tails side by side
- PDF, CSV and share links on everything
- One user
- Cancel any time
Pays for itself from the third report in a month.
Team
Unlimited for a whole firm: brokerages, dealers, lenders and acquisition teams.
From $4,995a month
- Everything in Unlimited
- For your whole team, up to 7 users
- One invoice for the firm
- Cancel any time
Before you order.
Anything else, ask us directly. A person replies.
What if there isn't enough history for my aircraft?
That's why checking is free. Enter the tail number and you see how much evidence exists before you pay. If a measure has too few comparable aircraft, the report shows it as context rather than grading it.
Does it replace a pre-purchase inspection?
No. It can't establish mechanical condition, maintenance quality or airworthiness. It tells your inspector and records reviewer where to look hardest, and which records to ask for first.
Which aircraft are covered?
20,348 business jets across 49 types from ten manufacturers. Every type is measured across all its aircraft, in every region. See every type.
How current is the data?
Every report states the date its data runs to and the aircraft's last observed flight. The record runs from 1 August 2025.
Will it name airports or show exact dates?
No. Airports and exact dates are left out on purpose. The report describes the kind of place, such as a field with an OEM service center, and the shape of its routes.
Can I share it with my client, lender or technical team?
Yes. Every report comes with a PDF, a CSV of the figures and a share link.
Does it value the aircraft?
No. Pricing and valuation are for your appraiser. TailCheck gives them, and you, a clear account of how the aircraft has been used.
Ask the hard questions while you still have leverage.
Free to check. $395 for the full report, or unlimited from $995 a month.