The quoted price on a rotable is rarely the full cost of getting it. Whether the deal is structured as an outright purchase, an exchange, or a loan changes what you actually pay, how fast you get the part, and what obligations follow you after the aircraft is back in service. Comparing quotes without accounting for that structure is comparing incomplete numbers.
The three models, in practice
Outright purchase is the simplest structure: you buy the part, you own it, there is nothing to return. It is usually the slowest option when the specific unit needs to be sourced rather than pulled from ready stock, because the seller is finding and preparing a part to sell, not shipping something already sitting on a shelf against a standing program.
Exchange means the supplier ships a serviceable unit from their own stock immediately, and you send your removed unit, the core, back to them within an agreed window. You are charged an exchange fee up front, and typically a core charge that gets refunded, in full or in part, once your core is received and evaluated. Exchange is usually the fastest path to a part in hand because the supplier is not sourcing anything new, they are drawing from a pool built specifically to support exchange transactions.
Loan means you receive a serviceable unit temporarily, often to keep an aircraft flying while your own unit is being repaired or overhauled elsewhere, and you return the loaned unit once your original part comes back. Loans typically carry a daily or flat rental fee for the loan period rather than a purchase price, and the commercial terms usually assume your own part is not lost or scrapped, just temporarily unavailable.
What a core charge actually is
A core charge is a deposit, effectively, tied to the expectation that you will return your removed unit, the core, to the supplier. It exists because the exchange model only works if cores keep coming back into the pipeline to be overhauled and returned to stock. If you never send a core back, you keep the core charge as a cost, on top of the exchange fee you already paid, which usually makes the total cost close to or higher than what an outright purchase would have been. The core charge is not a penalty, it is what keeps the price of the exchange itself low, because the supplier is counting on getting a repairable unit back.
Core return: what actually determines the refund
When your core arrives back at the supplier, it gets evaluated against the condition it was expected to be in, typically repairable and complete, not beyond economical repair and not missing components. A core that comes back in worse condition than expected, missing a required accessory, or outside the agreed return window, commonly gets a reduced credit or none at all. Before you ship a core back, confirm what condition and completeness the agreement actually requires, and hold onto proof of shipment and delivery. A core that gets lost in transit with no tracking is a cost you will not be able to dispute later.
Return windows are real deadlines, not suggestions
Exchange and loan agreements specify a window to return the core or the loaned unit, and that window is enforced financially. Miss it and you typically lose part or all of the core credit, or start accruing additional charges on a loan. Before agreeing to a return window, confirm your own operation can actually meet it: does the removed core need its own repair or paperwork prepared before shipment, is there a customs step if the core is crossing a border, and does your team have a process to make sure the return does not get forgotten once the aircraft is flying again and the urgency has faded. The return window is usually the part of the transaction most likely to be missed simply because attention moves on once the AOG is resolved.
Comparing the real cost, not just the quote
| Factor | Outright purchase | Exchange | Loan |
|---|---|---|---|
| Speed to part in hand | Often slower, sourcing required | Usually fastest, ships from ready stock | Fast, similar to exchange |
| Upfront cost | Full purchase price | Exchange fee plus refundable core charge | Rental fee for loan period |
| Core return required | No | Yes, within an agreed window | Yes, return the loaned unit |
| Risk if core not returned | None | Lose core charge, cost rises toward outright | Additional charges accrue |
| Ownership after transaction | You own the part outright | You own the exchanged unit, core goes to supplier | You never own it, temporary use only |
| Best fit | You want the part permanently and speed is not critical | You need a part fast and have a core to send back | Your own unit is being repaired and will come back |
How to actually decide
Start with whether you have a viable core to send back. If your removed unit is scrapped, missing, or clearly beyond economical repair, exchange pricing that assumes a healthy core return will end up costing you close to outright purchase once the core charge is forfeited, so compare against an outright quote before assuming exchange is cheaper. If speed is the priority and you have a good core, exchange is usually the right call. If the goal is simply to keep flying while your own unit gets fixed, and you expect to get that same unit back, a loan is often the cleanest structure because there is no core evaluation risk at all, you are just returning what you borrowed.
Weighing exchange against outright on a specific part number? Send us the details and we will lay out the real cost of each option.