Buying a partially completed homebuilt aircraft can save years of work or cost you far more than starting fresh. The difference lies almost entirely in how carefully you evaluate the project before money changes hands. This guide shows you what to inspect in the airframe, why the paperwork can matter more than the metal, and how the FAA major-portion rule affects whether you can even certify the finished aircraft as amateur-built.
Why Most Cheap Projects Are Cheap
Understand the seller’s situation first. Projects come to market for ordinary reasons, such as health, money, or lost interest, but also because the builder hit a wall they could not solve. A suspiciously low price often reflects hidden problems: poor workmanship, missing documentation, or a design the builder discovered was beyond their skill. The bargain is real only when the reason for selling is unrelated to the quality of the work.
The Paperwork Comes First
Before you look at a single rivet, look at the documentation. For an amateur-built project this is not bureaucracy; it determines whether you can legally finish and register the aircraft.
The Builder’s Log
A complete, dated, photographed builder’s log is the single most valuable document. It shows who built what, when, and how. Without it, you cannot prove who performed the work, which matters for the certification path. A project with a thorough log is worth substantially more than an identical airframe with none.
The 51% (Major Portion) Rule
The FAA amateur-built category requires that the major portion of the aircraft be .
Inspecting alone. Fix: pay an experienced type-specific builder or counselor to look with you.
Assuming the amateur-built path is guaranteed. Fix: confirm the kit’s FAA listing and understand how prior work affects the major-portion requirement before you buy.
Evaluation Checklist
- Ask directly why the project is being sold.
- Demand the complete builder’s log and photos.
- Confirm the kit appears on the FAA approved amateur-built listing.
- Bring a type-experienced inspector or EAA Technical Counselor.
- Inspect for corrosion, delamination, and rivet quality.
- Inventory every included component against the plans.
- Verify engine, propeller, and avionics existence and condition.
- Price the project against a fresh kit plus your labor, not against the seller’s sunk cost.
Conclusion and Next Step
A partial project is only a deal when the workmanship is sound and the paperwork supports certification. Your next step before any purchase: request the full builder’s log and confirm the kit’s FAA amateur-built listing. If either is missing, negotiate hard or keep looking.
Frequently Asked Questions
Is a more complete project always more valuable?
No. Completion built poorly can force you to disassemble finished work, which is slower and costlier than building from a fresh kit. Quality and documentation drive value more than percentage complete.
Can I still certify it as amateur-built if I did not build the major portion?
It depends on how much amateur work was done and how it is documented. The FAA major-portion requirement governs eligibility, so verify the situation before assuming the amateur-built path is open to you.
What if there is no builder’s log?
Treat it as a serious problem. You lose the record of who did what, which weakens your certification documentation and your ability to trust the workmanship. It justifies a large discount or walking away.
Do I need a professional to inspect it?
Strongly recommended. An EAA Technical Counselor or an experienced builder of that type will spot problems a first-time buyer cannot, and their fee is small against the purchase price.
References
- FAA National Kit Evaluation Team (NKET) approved amateur-built kit listing.
- FAA Advisory Circular AC 20-27, Certification and Operation of Amateur-Built Aircraft.
- Experimental Aircraft Association (EAA) Technical Counselor program.