When is it advised to avoid issuing a frequency change to a single piloted helicopter?

The advice to avoid issuing a frequency change to a single piloted helicopter during air taxiing and hovering stems from the operational complexities and demands placed on the pilot in such scenarios. When a helicopter is air taxiing or hovering, the pilot’s attention is primarily focused on maintaining control of the aircraft, ensuring safe altitude, and managing the surrounding environment.

In these stages of flight, distractions can significantly elevate the risk of error. A frequency change could divert the pilot's attention from critical visual cues and aircraft control, which is particularly crucial when close to ground level or in busy airspace. Therefore, it is considered safer to wait until the helicopter has transitioned to a more stable and less demanding phase of flight, such as cruising, where the pilot can concentrate on the frequency change without immediate control concerns.

While other phases like landing procedures or transitioning to holding patterns may also be critical, the very specific challenges of maneuvering during air taxiing and hovering make this situation the most critical for avoiding frequency changes to ensure the pilot's focus remains on the aircraft's control and the immediate environment.