Start with the mission, not the aircraft
Almost every bad aircraft purchase starts with a type rather than a requirement. Somebody flies on a friend's jet, likes it, and starts hunting for that model. Two years later they are selling it because it cannot reach the one destination they actually fly to with a full cabin.
The requirement that matters fits in a sentence. How many people, how far, how often, out of which airport, in what weather. Each of those narrows the answer, and they interact. A 1,400 metre runway at a hot and high field removes half the candidates before range is even discussed.
Write the requirement down before you look at a single listing. A broker who does not ask for it is telling you something about what they are selling.
Book range is a still air, zero wind, long range cruise figure. Plan against roughly 85 per cent of it with a full cabin, and less again westbound in winter.
Searching the market and building a shortlist
Between three and twelve per cent of any fleet is for sale at a given moment, and only part of it is advertised. A proper search covers the listed market, the aircraft whose owners would sell at the right number, and the ones coming off lease in the next six months.
A shortlist runs to three or five aircraft, ranked, with a written reason each one is on it and a written finding that would take it off. A list of twenty aircraft means nobody has done the work yet.
The letter of intent
The letter of intent fixes the price, the deposit, the scope of the inspection and the conditions under which either side walks away. It gets signed before anyone travels, and it decides who pays for what once the inspection finds something.
The most valuable clause says that discrepancies affecting airworthiness are corrected at the seller's cost and everything else is negotiated. Without it, an inspection that turns up a hundred thousand dollars of work becomes an argument instead of an adjustment.
The pre-purchase inspection
The inspection happens at a facility with no commercial relationship to the seller, and ideally none to the buyer either. It covers the airframe, the engines by borescope, the logbooks back to delivery, the areas prone to corrosion on that type, and compliance with every applicable airworthiness directive.
Reviewing the logbooks is not paperwork. Gaps in the record cut the value permanently, because the next buyer discounts them too. A missing engine trend monitoring history can cost more than the whole discrepancy list.
Budget one to three per cent of the purchase price for the inspection and the corrections that follow. On an aircraft that has been parked, budget more.
Escrow, title and closing
Purchase money goes to an independent escrow agent, never to the broker. That agent also runs the title search. Liens, mortgages, tax claims and unreleased security interests survive a sale unless they are cleared, and an aircraft can still carry one left by a maintenance shop three owners ago.
Closing is the simultaneous exchange of funds, bill of sale, deregistration from the old registry and registration on the new one. It is the only moment in the transaction where everything happens at once, and it normally takes a single morning.
Where deals actually fall apart
Three places, in order of frequency. The inspection finds something and the letter of intent did not say who pays. The buyer's financing was indicative rather than committed, and the credit committee says no after the deposit is placed. An import or export requirement nobody checked, such as a registry that will not accept the type, a certificate of airworthiness that cannot transfer, or a tax position that moves the price by twenty per cent.
All three are avoidable. All three are avoided by doing the boring work before the exciting part.