Rotables in the Aviation Industry: A Deep Dive into Operations and Practices

September 25, 2023 by
Rotables in the Aviation Industry: A Deep Dive into Operations and Practices
Roland Pinto

The aviation industry, with its vast expanse and intricate operations, is a marvel of modern engineering and logistics. Among its many facets, one segment that plays a pivotal role yet often remains behind the scenes is the world of 'rotables'. In this comprehensive article, we'll explore what rotables are, how the rotables segment operates, and delve into the standard practices surrounding their sale and purchase.

What are Rotables?

Rotables refer to aircraft components that can be repeatedly and economically restored to a fully serviceable condition after they have reached the end of their service life. These parts are removed, overhauled, and then placed back into service, often multiple times over the course of their lifespan. Examples of rotables include landing gear, engines, engine accessories, and avionics components.

How Does the Rotables Segment Operate?

The operation of the rotables segment is characterized by a cycle of usage, removal, refurbishment, and reinstallation:

  1. Usage: The rotable part is used in the aircraft until it reaches the end of its service life or requires maintenance.
  2. Removal: Once deemed unserviceable, the part is removed from the aircraft.
  3. Refurbishment: The part is then sent to a maintenance facility where it's overhauled, repaired, or modified to bring it back to a serviceable condition.
  4. Reinstallation: Post-refurbishment, the rotable is either stored for future use or immediately reinstalled in an aircraft.

Standard Practices for Selling and Purchasing Rotables

  1. Documentation: Given the critical nature of aviation components, every rotable part comes with extensive documentation that details its history, repairs, modifications, and overall condition.
  2. Warranty: Sellers often provide warranties for rotables, ensuring their functionality and reliability post-purchase.
  3. Quality Assurance: Before a sale, rotables undergo rigorous quality checks to ensure they meet aviation standards.

Core Exchanges and Core Deposits

A core exchange is a common practice in the rotables segment. Here's how it works:

  1. Exchange Basis: When an operator needs a replacement part immediately, they can obtain a refurbished part (the exchange unit) from a supplier. In return, they send their unserviceable part (the core) to the supplier.
  2. Core Deposit: To ensure the return of the unserviceable part, suppliers charge a core deposit. This deposit is refunded once the supplier receives the core and deems it repairable.

Why is a Core Deposit Important?

The core deposit serves multiple purposes:

  1. Guarantee of Return: It ensures that the operator returns the unserviceable part, allowing the supplier to refurbish it and keep the cycle going.
  2. Economic Viability: Refurbishing and selling rotables is economically viable for suppliers only if they continuously receive unserviceable parts to overhaul.
  3. Inventory Management: Core deposits help suppliers maintain a steady inventory of parts to refurbish, ensuring a consistent supply in the market.

A Real Life Example

Liberty Air Charters, a premier on-demand charter service based in Maryland, USA, boasts a fleet of sleek Learjet 60 aircraft. Every 600 flight hours, the Learjet's stabilizer actuator, known by its part number 5435005-028 or "stab actuator," necessitates a comprehensive service. The director of maintenance or their team oversees its removal and inspection. Subsequently, the parts manager accesses their account on to initiate a core exchange.

Promptly, AirParts Aero dispatches an overhauled stab actuator to Liberty. Upon its arrival, Liberty's team installs the new actuator and sends the old one back to AirParts Aero. This returned part is then forwarded to an overhaul partner for refurbishment.

To ensure the return of the old actuator, Liberty places a core deposit with AirParts Aero during the initial purchase. This deposit not only guarantees the part's return but also facilitates its repair and overhaul. If the returned actuator from Liberty exhibits issues beyond regular wear and tear, the overhaul process incurs additional costs for AirParts Aero. These extra expenses, stemming from atypical repairs, are subsequently billed to Liberty and deducted from the core deposit. Once the overhaul is complete and all associated costs settled, AirParts Aero refunds the remaining core deposit to Liberty, providing a detailed breakdown of additional repairs and any parts procured for the overhaul.


Rotables are the unsung heroes of the aviation industry, ensuring aircraft remain operational by undergoing cycles of refurbishment and reuse. The practices surrounding their sale, purchase, and exchange are meticulously designed to maintain the highest standards of safety and efficiency. As the aviation industry continues to grow, the rotables segment will undoubtedly remain a cornerstone of its success.