Waiting for an aircraft part to be repaired or overhauled may take too long, and buying a part outright may be too expensive. Purchasing a part on exchange is a quick and cost-effective way to receive a serviceable part, ready for installation on your aircraft.

There are a few different exchange options, but they all require a core return. The core (or off-unit) is the part that is removed from the aircraft and traded for the serviceable exchange unit. This may seem very straightforward, but the core return process can be more complex.  

We get asked about the core return process all the time – everything from what cores are accepted on exchange, what documentation to include, how to ship the core, and what to do if the core is unable to be repaired. In this article, we answer your questions, providing you with the information you need about the core return process.

What are the Options for a Core Return?

The core offered in exchange should be the same part number (or an acceptable alternate) as the exchange unit. The core must not have been involved in an incident and must be capable of being refurbished to the same condition as the exchange unit for the supplier to resell. 

Alternate Part Numbers

Sometimes alternate parts are acceptable as cores. An alternate part will have a different part number than the exchange unit but is interchangeable with that unit.

The buyer should research whether an alternate part is acceptable. Not all alternates are interchangeable, depending on the type of aircraft on which they are being installed.

Due to company policies, the supplier may choose not to accept an alternate part number, even if it is interchangeable. 

A Repaired or Overhauled Core

In some cases, a supplier will accept back a core that has already been repaired or overhauled (to the same condition as the exchange unit) by the buyer’s repair vendor.

This happens when a buyer sends their core out for repair, then can’t wait for maintenance to be completed. The buyer offers their core in exchange for a part they can obtain sooner.

The supplier must approve the repair vendor before exchanging the repaired or overhauled part.

What is Trace Documentation?

To accept a core back in trade, many suppliers require a specific “Core Return Form” with key trace details. Trace documentation will usually include the following:

• Non-incident Statements – Cores should include a non-incident statement. This indicates that the core was not taken from a U.S. Government or Military source and was not subject to severe stress or heat, was immersed in salt water, or was involved in a major engine failure, accident, incident, or fire. Cores from aircraft that have been involved in any of the above are usually not accepted in exchange.
• Who Removed the Part from the Aircraft – Cores should include documentation with a signature from an authorized company representative (most likely an A&P Mechanic) who removed the part from the aircraft.
• What Aircraft Did the Part Come From – Cores should include information about the aircraft from which the part was taken. This would include the aircraft’s serial number, registration number, etc.
• Time/Cycles – Some cores should include information about how much time or how many cycles are on the part. For example, a TSO (time since overhaul) or CSO (cycles since overhaul) help calculate when the part needs to be overhauled again. If the part has a limit on its allowable life, it might have a TSN (time since new) or CSN (cycles since new).

What Do You Need to Know About Shipping the Core?

Specific Packaging

Aircraft parts may require special packaging, specified on the supplier’s notes or quotes. The D.O.T. may also require specific packaging and labeling for shipping aircraft parts, such as HAZMAT parts.

You may be required to return your core in the same packaging the exchange unit arrives in, or you may have to acquire that specific packaging before shipping the core to the supplier. For instance, if a windshield is shipped in a crate from the supplier, the core windshield must be returned in that crate or another just like it.

Using inadequate packaging could result in the core being damaged. You may be billed for a replacement package. Be sure to always use appropriate packaging.

Timeframe for Shipping

Core due dates are specified on the quote, sales order, or exchange agreement. Cores must be sent to the supplier before the core due date.

If the core must pass through customs, there may be delays. Anticipating possible delays into your shipping time may help to ensure the core arrives before the due date.

Additional exchange fees or core billing will be charged if the core is not received on time.  

What if the Core is BER?

Cores are deemed beyond economical repair (BER) if the cost to repair or overhaul exceeds the value of the core.

If you learn that the core is BER after sending it to the supplier’s repair vendor, the supplier may allow you to send a (hopefully) better core for evaluation. If the supplier will not accept another core (or you do not have a second core), you will be responsible for the core charge and any additional fees incurred. 

Core Advice

If you have questions about when the core is due, what documentation needs to be included with the core, or what the supplier defines as BER, always feel free to ask the supplier. You may also consult the exchange agreement provided by your supplier that outlines the terms and expectations of the exchange. Suppliers should be willing to discuss their specifications for exchanging a core.