The 61915-003 is a Piper OEM spring used in the elevator trim control system, typically identified as part of the mechanical linkage that provides tension and return force within the trim mechanism. In aircraft such as the Piper PA-38 series (and related variants), this spring is part of the elevator trim system that helps maintain trim wheel feedback, stabilizes trim cable tension, and contributes to the aerodynamic balance of the elevator through the trim tab or stabilator control system.

The elevator trim system allows the pilot to relieve control forces on the yoke by adjusting the neutral position of the pitch control surface. This spring plays a key role in ensuring consistent mechanical resistance and proper return characteristics of the trim assembly, helping maintain smooth and predictable trim response during flight.

Depending on aircraft configuration, the 61915-003 spring may be installed in conjunction with trim cables, pulleys, and the trim wheel assembly in the cockpit or tail section. It is a fatigue-sensitive component, operating under repeated tension cycles, and is therefore subject to periodic inspection for elongation, corrosion, or loss of elasticity.

In Piper parts catalogs, this component may also appear in elevator trim control kits or be referenced as an alternative or superseding part depending on aircraft serial number and configuration.

Key features include:

Piper 61915-003 elevator trim control spring
Used in elevator/stabilator trim system mechanical linkage
Provides tension and return force in trim mechanism
Supports trim wheel feedback and control stability
Installed with trim cables, pulleys, and control assemblies
Material: high-carbon spring steel or corrosion-resistant alloy steel
Designed for repeated cyclic loading in vibration-heavy environments
Critical for consistent pitch trim behavior and control feel
Used in light aircraft elevator trim systems (model-dependent)
Subject to periodic inspection for fatigue, corrosion, or deformation