A pre-buy survey is the moment when every flaw in paint, brightwork and cabin becomes a line item in the buyer's negotiation. Inspectors document oxidation on nacelles, corrosion bloom around fasteners, fluid staining on the belly and worn cabin materials—all of which translate directly into price reductions or deferred-sale clauses. Detailing before the inspection removes the cosmetic flags that distract from airworthiness and preserves the seller's position at the table.
What does a pre-buy inspector actually check on the exterior?
Airworthiness inspectors and independent surveyors follow a structured walk-around that includes paint condition, corrosion indicators and fluid leaks. The CAA's Guide to Pre-Purchase Inspection and EASA Part-M continuing airworthiness standards both require documentation of "general condition," which includes finish integrity and corrosion evidence.
Inspectors look for:
- Paint oxidation and chalking on horizontal surfaces (wing leading edges, nacelle tops) where UV exposure is highest
- Corrosion bloom around fasteners, door seals and belly panels—white or green deposits that indicate active aluminium corrosion
- Fluid staining from hydraulic weeps, APU exhaust residue or lavatory service ports
- Delamination or chipping on composite fairings and radome edges
- Brightwork pitting on window frames, door handles and exhaust bezels
Even minor issues are photographed and logged. A 2019 Business & Commercial Aviation article on pre-buy pitfalls noted that cosmetic defects often trigger deeper structural inspections, adding weeks to the survey timeline and unsettling buyers.
How does paint condition affect valuation?
Paint is not merely cosmetic; it is the primary corrosion barrier on aluminium airframes. The Aircraft Fleet Recycling Association's Best Practice Guide states that compromised paint accelerates corrosion, particularly in high-salinity or industrial environments. Surveyors use paint condition as a proxy for maintenance quality.
Oxidised or chalky paint suggests:
- Deferred exterior care, raising questions about hidden maintenance lapses
- Reduced hydrophobic protection, meaning faster future degradation
- Potential corrosion beneath the surface layer, which requires costly NDT inspection
A single-stage machine polish removes oxidation and restores gloss without removing significant paint thickness. This is standard practice before any pre-buy; it costs far less than the valuation hit from a surveyor's "poor exterior condition" notation in the TLB.
What cabin details do inspectors document?
Cabin condition is weighted heavily in pre-buy reports because refurbishment costs are predictable and high. The National Aircraft Resale Association's Valuation Guidelines list cabin wear as a primary adjustment factor, with refurbishment costs ranging from $500,000 to $3 million depending on aircraft size.
Inspectors photograph and note:
| Item | What they flag |
|---|---|
| Leather seating | Cracking, discolouration, piping separation |
| Carpet and soft goods | Staining, odour, wear patterns in high-traffic zones |
| Veneer and cabinetry | Delamination, water damage, mismatched grain from repairs |
| Galley and lav | Corrosion around sinks, cracked countertops, worn faucet finishes |
| Windows and side ledges | Crazing, yellowing, dust in gasket channels |
OEM cabin-care guidelines from Gulfstream, Bombardier and Dassault all specify pH-neutral cleaners and conditioners for leather and veneer. Inspectors know these standards; they will note if materials look neglected or cleaned with harsh products that have stripped protective coatings.
Can you remove corrosion bloom without repainting?
Early-stage corrosion—white powdery deposits around fasteners or seams—can often be arrested and cosmetically improved without a full repaint, but only if caught before pitting begins. EASA Part-M Subpart C requires that corrosion be evaluated and, if within limits, treated and documented.
The process involves:
- Decontamination with a pH-balanced decon solution to remove salt, exhaust residue and industrial fallout
- Localised corrosion removal using non-abrasive methods (Scotch-Brite pads, aluminium-safe compounds) per the aircraft maintenance manual
- Touch-up or sealant application if the corrosion has not penetrated the primer
- Documentation in the tech log so the inspector sees remedial action, not deferred maintenance
Boeing's Document D6-54446 on corrosion prevention notes that removing surface corrosion and applying a protective wax or sealant can extend repaint intervals by years. Inspectors appreciate seeing this work logged; it signals proactive care rather than a quick cosmetic cover-up.
Why does brightwork matter in a sale?
Polished aluminium and stainless-steel components—window frames, door handles, exhaust bezels, nacelle rings—are visual shorthand for overall maintenance standards. Pitted, stained or dull brightwork suggests long-term neglect, even if the airframe hours are low.
Brightwork degradation occurs when:
- Oxidation forms a dull grey layer on bare aluminium (common on older Challengers and Falcons with polished nacelle rings)
- Exhaust staining etches into steel bezels around APU and engine outlets
- Corrosion pits stainless components exposed to deicing fluid or salt spray
Restoration involves progressive polishing with aluminium-safe compounds and a final protective sealant. The AMT Handbook published by the FAA describes brightwork care as part of corrosion control, not optional detailing. Inspectors photograph brightwork closely; restored components photograph well and remove a common objection.
What about fluid stains and belly grime?
The belly and lower fuselage collect hydraulic mist, lavatory service residue, APU exhaust soot and runway deicing fluid. Inspectors look at the belly to identify active leaks and deferred maintenance. A clean belly allows them to see the airframe, not the operational history.
A proper belly decon involves:
- Rinseless or dry-wash methods if water access is restricted airside
- Degreasing agents safe for aluminium, composites and sealants (per OEM-approved product lists)
- Inspection of all panels and fasteners after cleaning, so any weeps or corrosion are visible and can be addressed before the surveyor arrives
The International Aircraft Dealers Association notes in its Best Practices for Aircraft Sales that a clean aircraft signals transparency; a dirty one raises suspicion. Buyers and their inspectors assume the seller is hiding something if the aircraft arrives for pre-buy survey still covered in operational grime.
How Terso prepares aircraft for pre-buy inspection
We work directly on the ramp or in the hangar during the days before a survey, coordinating with the flight department to ensure the aircraft is inspection-ready without pulling it off the line. Our pre-buy detailing includes exterior decon and polish, brightwork restoration, cabin deep-clean to OEM standards, and documentation of all work for the tech log. Learn more about our pre-purchase detailing service.
Sources
- CAA CAP 747 – Mandatory Requirements for Airworthiness
- EASA Part-M (Regulation (EU) No 1321/2014) – Continuing Airworthiness Requirements
- Business & Commercial Aviation – Pre-Buy Inspection Pitfalls (2019)
- Aircraft Fleet Recycling Association – Best Practice Guide for Management of End-of-Life Aircraft
- Boeing Document D6-54446 – Corrosion Prevention and Control
- FAA Aviation Maintenance Technician Handbook – General (FAA-H-8083-30A)