Definition
A service in which air traffic control (ATC) helps pilots avoid hazardous weather by providing radar-observed precipitation information, suggesting headings or routes around weather, and coordinating deviations from the flight plan. The service is provided on a workload-permitting basis and does not relieve the pilot of the responsibility for weather avoidance decisions.
Plain English
Help from air traffic controllers to steer clear of bad weather. They can tell you what they see on radar and suggest a way around it, but the final call about how to avoid the weather is still the pilot's.
Context Anchor
Seen in instrument flying when a pilot is using air traffic control services and needs help avoiding rain, storms, or other unsafe weather along the route.
Why Pilots Care
Direct assistance reduces the chance of an inadvertent encounter with weather that could cause loss of control or force an emergency diversion.
Grounding Statement
A pilot might see a storm building ahead, ask air traffic control for help, and receive information or a route change to stay away from it.
Intuition Check
Do not assume “assistance” means air traffic control is responsible for keeping you clear of all weather. Here it means help when available; the pilot still has the final responsibility for safe weather avoidance.
Example Sentence 1
Approaching a line of thunderstorms, the pilot requested weather avoidance assistance and was given a 20-degree heading change to route around the cells.
Example Sentence 2
We requested weather avoidance assistance from Flight Service before departure when the outlook showed possible convective activity.