Aircraft Prebuy Inspection: Define the Scope Before the Mechanic Starts
A prebuy is a buyer-defined condition and records review, not a standard FAA inspection. Build a written scope, evidence pack and decision record before closing.
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Updated July 16, 2026
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An aircraft prebuy is not a named FAA inspection with one mandatory checklist. It is a buyer's agreed review of condition, configuration and records before a transaction. Its value depends on the written scope, the inspector's qualifications and independence, and what happens when the first discrepancy appears.
This article replaces a checklist that made unsupported claims about common defects and what every inspector should do. The revision builds from FAA maintenance and ownership records and leaves aircraft-specific inspection content to the applicable data and mechanic.
A prebuy is not automatically an annual inspection
The FAA Plane Sense handbook advises a prospective buyer to have a mechanic they rely on perform a thorough inspection and provide a written condition report. It also says a prepurchase inspection need not be an annual inspection.
That distinction should be explicit in the work order. A prebuy can identify conditions relevant to a purchase without completing every task, authorization and record entry required for an annual. If the parties intend to convert the work into an annual inspection, the appropriately authorized person, complete scope, discrepancies and record outcome need to satisfy the annual rules.
Do not let “prebuy,” “annual-level” and “annual” become interchangeable words in the quote.
Define the decision before defining the inspection
The buyer and mechanic should agree what question the work must answer:
- Is the identity and configuration supported by the records?
- What known discrepancies or maintenance actions are open?
- What condition evidence can be obtained within the agreed access and disassembly limits?
- Which findings require specialist review or a deeper inspection?
- What would cause the buyer to stop, renegotiate or proceed?
The purchase agreement, deposit, access permission, test-flight authority, damage responsibility and response to findings are transaction terms. Aviation maintenance evidence can inform them, but legal and title advice may be needed separately.
Assemble the records before opening the aircraft
A useful prebuy pack can include:
- registration and airworthiness documents;
- airframe, engine, propeller and appliance records;
- total-time and time-in-service reconciliation;
- current inspection status and the applicable inspection programme;
- airworthiness-directive status;
- major repair and alteration records, including Form 337 where applicable;
- supplemental type certificates and approved data supporting installed changes;
- current weight-and-balance and equipment records;
- life-limited and overhaul-status evidence relevant to the aircraft; and
- known damage, occurrence and insurance records available to the parties.
14 CFR 91.417 defines maintenance records that must be retained and transferred with the aircraft. Active AC 43-9D provides current FAA guidance on maintenance record-making and retention.
A neat stack of logbooks is not the same as a reconciled record. The review should identify gaps, inconsistent times, missing alteration data and statements that cannot be tied to a signed entry.
Use independent public records as cross-checks
The FAA Aircraft Registry provides registration search and a process for requesting copies of aircraft records. Those records can help cross-check identity, ownership filings and documents held by the Registry, but they are not a complete maintenance history or a title opinion.
The FAA Airworthiness Directives page is the starting point for current federal AD research. Applicability and compliance still need to be established against the specific product, serial number, configuration and maintenance entries.
The NTSB aviation occurrence database can be searched by registration and other fields. A result can lead to relevant records; no result does not establish an accident-free history because registration, jurisdiction, reporting and database coverage have limits.
Write a type-specific physical scope
The physical scope should come from the aircraft's approved data, maintenance instructions, configuration, history and known type concerns. It can state:
- panels or areas to be opened and who will restore them;
- engine and propeller condition checks and their limitations;
- corrosion, structure, control, landing-gear and system areas to inspect;
- functional checks and whether a ground run or test flight is authorized;
- avionics configuration and paperwork reconciliation;
- sampling methods that do not cover the whole component; and
- stop-work and additional-authorization thresholds.
A compression reading, borescope image or oil report is one piece of evidence. None should be turned into a universal pass/fail rule outside the applicable manufacturer and maintenance context.
Independence needs a disclosed relationship, not a slogan
Ask the inspector to disclose current or expected relationships with the seller, broker, listing platform and shop that would receive corrective work. A prior relationship does not automatically invalidate the inspection, but the buyer should know it before setting the scope.
Also confirm:
- certificate and inspection authorization needed for the intended work;
- familiarity with the specific aircraft and installed engine or systems;
- professional-liability terms and report limitations;
- who owns photographs, samples and test data; and
- whether estimates for corrective work are inspection findings or a separate commercial proposal.
Require a written decision record
The final report should distinguish:
- observed condition;
- record evidence reviewed;
- discrepancy or unresolved question;
- work outside the agreed scope;
- maintenance performed and its separate return-to-service entry;
- specialist follow-up; and
- estimates or opinions with their assumptions and date.
The buyer can then maintain a disposition table: accept, require evidence, obtain a quote, amend the agreement or stop. That is more useful than a generic “good prebuy” conclusion.
Questions to settle before work begins
- What exact inspection and records scope is included?
- Is this a prebuy only, an annual, or a staged path that may become an annual?
- What access, disassembly, engine operation and test flight are authorized?
- Who approves and pays for work beyond the initial scope?
- What findings trigger immediate notice or stop-work?
- Which public and Registry records will be cross-checked?
- What written report, images and test results will the buyer receive?
- How will maintenance performed during the inspection be recorded?
The inspection cannot remove every ownership risk. It can make the evidence, unknowns and commercial decision visible before closing.
