Aircraft Pre-Purchase Inspection (PPI) — Complete Buyer's Guide | AeroGurus

The Aircraft Pre-Purchase Inspection (PPI): A Complete Guide

A pre-purchase inspection (PPI) is the single most important step in buying a used aircraft. It is an independent assessment of the aircraft's present condition and the accuracy of its records, carried out before you commit — and it routinely pays for itself many times over by catching problems the seller's photos and asking price never show.

What a PPI is — and isn't

A PPI is not an annual inspection and not a guarantee. It is a focused, buyer-commissioned evaluation of airworthiness, condition, records and value, scoped to the aircraft and your budget. A good PPI answers three questions: Is the aircraft airworthy and safe? Do the logbooks match the airplane? And are there hidden or looming costs (corrosion, run-out components, deferred maintenance, damage) that should change the price or the decision?

Choosing the inspector — independence and type experience

Two rules: the inspector must be independent of the seller, and must know the type. A mechanic who regularly works on the model knows where it hides corrosion, which ADs bite, and what "normal wear" looks like versus a problem. Avoid using the seller's own shop for the PPI. For complex, high-performance, turbine or helicopter purchases, a type specialist is essential, not optional.

What a thorough PPI covers

• Logbook and records audit — total times, engine/prop times since overhaul, AD/Service Bulletin compliance (recurring and one-time), damage history, and record continuity.
• Engine health — compression test and a borescope of cylinders, oil analysis history, and signs of corrosion or metal — the costliest single area to get wrong.
• Corrosion and structure — the airframe's known corrosion-prone areas (especially on older or coastal/float aircraft), control surfaces and attach points.
• Gear, systems and avionics — landing gear and (on retractables) gear cycling, hydraulics, electrical, fuel system, and verification that installed avionics work and are current.
• Cosmetics last — paint and interior matter least to airworthiness; don't let a nice paint job distract from the logbooks and the engine.

Scope by aircraft class

The PPI scope scales with the aircraft. Each class has its own decisive items, summarised on our per-model safety pages:

• Piston singles/twins — engine compression/borescope, corrosion, and (on retractables) the gear system are central. See examples like Cessna 182 safety or a classic retractable's watch-items.
• Turboprops and jets — the engine/maintenance-program status (hot-section, overhaul, hours/cycles) dominates value and airworthiness; verify program enrolment and airframe cycles.
• Helicopters — dynamic-component times-to-overhaul (rotor, transmission, gearbox) are the dominant safety and cost factor; a rotorcraft PPI lives or dies on component times.
• Amphibians and bush aircraft — hull/corrosion integrity and hard-cycle structural wear; gear-position systems on amphibians are safety-critical.
• Warbirds, vintage and homebuilts — provenance, build/restoration quality, and (on wood/fabric) structural condition; original-vs-reproduction status transforms value.

Deliverables and negotiation

A PPI should produce a written report with findings categorised by severity (airworthiness items, recommended items, cosmetic). Agree in advance how findings affect the deal: a price adjustment, the seller rectifying airworthiness items before closing, or a walk-away for deal-breakers. Discovering a problem during the PPI is a success, not a setback — it's exactly what the inspection is for.

Deal-breakers and red flags

• Failed compression or borescope findings (cylinder/valve/corrosion issues).
• Significant structural corrosion or poorly-documented damage repair.
• Missing or non-compliant AD records.
• On turbines, an engine off its maintenance program or with undisclosed cycles.
• On helicopters, dynamic components near or over time-to-overhaul presented as "fine."
• A seller who resists an independent, type-experienced inspection — the biggest red flag of all.

How much a PPI costs

A PPI costs a fraction of the aircraft and a tiny fraction of what an undiscovered problem can cost. Budget for the inspection, your travel, and possibly a ferry/positioning flight. It is the cheapest insurance in the entire purchase.

When you're ready, start by choosing the right type with our model pages and aircraft comparisons, review the how-to-buy-a-used-aircraft guide, then let an independent, type-experienced PPI make the final call.