Methodology
How PlaneSnipe counts.
Every number on this site comes from one daily read of Barnstormers, kept since Jul 19, 2026. This page says exactly what each figure means, and what it does not.
What does PlaneSnipe actually read?
Once a day, in the small hours, PlaneSnipe fetches the piston single and twin categories on Barnstormers. From each ad it keeps the title as the seller typed it, the asking price, the state, the category and the link. It does not download photos, and it does not keep the seller's name, phone number or email. Turbines, helicopters, parts, partnerships and "wanted" ads are recognized and set aside; they are not part of any figure here.
The fetch is deliberately slow and polite: one page at a time, several seconds between requests, a few hundred pages a day. Adding users to PlaneSnipe does not add load to Barnstormers.
How does a seller's title become a make and model?
Sellers type free text. "1974 CESSNA SKYLANE 182P, NICE!" has to become Cessna, 182, 1974 before it can be counted with the other Skylanes. PlaneSnipe matches titles against a table of about 250 known types and their common spellings. When a title cannot be matched, the listing is still tracked but does not appear on a model page. Right now 87% of aircraft titles match a type.
The year is read only from the title. Around a third of listings do not state one, so the decade tables on model pages cover fewer aircraft than the price figures do.
What exactly is a median asking price, and what is a cut?
All prices are asking prices. "Call", "make offer" and "price reduced" with no number are recorded as unpriced. Median asking price is the middle value of the priced live listings for that type on the day the page was built; medians are used rather than averages because one project airframe at $23,900 or one turbo-normalized restart at $575,000 would otherwise move the number for everyone.
A price cut is recorded when the asking price of a listing is lower than the price recorded on the previous read. A price raise is recorded the same way, but is rare and is not counted as a cut. The percentage shown is the cut relative to the previous asking price.
Does a delisting mean the aircraft sold?
A listing is marked delisted after it has been missing from Barnstormers on two consecutive mornings. That means the ad came down. Sometimes the plane sold, sometimes the seller gave up, sometimes the ad expired and was relisted with a new number. PlaneSnipe does not know which, and does not claim to. Nobody has real transaction prices for private aircraft sales.
The naive median said seven days. The honest answer is months.
How is days on market calculated?
The naive way to compute days on market is to take every listing that has come down and average how long it was up. That number is badly wrong while the observation window is short: a listing can only be seen closing if it both appeared and disappeared inside the window, so long-lived listings, which are the majority and the interesting ones, are invisible to it. In the first fortnight that method reported a median of seven days for a market where the honest answer is months.
So PlaneSnipe does two things. First, it measures durations only over listings it watched appear. The standing inventory found on the first day had already been listed for an unknown time; those rows are tracked, but they do not contribute a duration. Second, it does not report a median until more than half of that cohort has actually closed. Until then it reports the survivor fraction: the share of listings still for sale a fixed number of days after first appearing. That figure is unbiased from day one and answers the same question from the other side.
There is a larger caveat on top of all of this, and it took a full quarter of data to see. Seven adverts in ten come down on exactly the same day of their life, because that is when the marketplace's advert term expires rather than when anything is bought. A median days-listed figure is therefore measuring the advert cycle far more than it is measuring the market, which is why the figure reads almost the same for every type. The 31-day wall sets out the distribution and what it does and does not let you conclude. Read any days-listed number here as how long that advert has been standing, which is exactly what it is.
Why do some types have no page, and when is a median too thin to trust?
A type gets its own page once 20 listings of it have been seen. Below that, a median is a guess. Types under the threshold are still tracked and still trigger alerts. Even above it, read a median on a thinly listed type like the Waco with more caution than one drawn from eighty live Skylanes: the figure is honest about what was asked, but a handful of aircraft cannot describe a market.
What is PlaneSnipe not?
PlaneSnipe is not an appraisal, not a valuation service, and not affiliated with Barnstormers. It is a record of what sellers asked and how long they asked it for. Use it the way you would use a logbook: as evidence, not as a verdict.
Cite this page: PlaneSnipe, "How PlaneSnipe counts", updated Oct 18, 2026, https://planesnipe.com/methodology/. Built from every used piston aircraft listing on Barnstormers, read each morning since July 2026. How it is measured.