Check what the view covers

A sunlit face can clear before a shaded edge or sheltered recess. A ground image may not show the back of a blade, cover interfaces or other affected parts. Improved air temperature also does not prove every component has warmed equally. Describe the observed clear regions and the areas that remain unobserved; do not substitute a general statement that the turbine is ice free.

Consider the event consequences

The assessment can require more than confirming that an external layer melted. Any reported abnormal motion, debris impact or displaced cover needs its own physical review. A normal-looking static rotor cannot resolve every prior event concern. Qualified personnel should determine the necessary scope without forcing motion, bypassing restrictions or approaching the turbine simply because fragments have stopped falling. This page does not provide a field restart test.

A thaw observation and a damage assessment answer different questions. Even if the first establishes that visible surfaces cleared, any independently reported impact or abnormal movement still needs its own closure before the overall equipment condition can be considered resolved.

Use a defined release decision

Ask which evidence and authority the applicable instructions require for resuming operation and whether any outstanding condition prevents release. A weather forecast or a nearby clean structure cannot stand in for the turbine-specific finding. DNV treats detection, manuals and protection within icing assessment; it does not establish a universal restart temperature. MARSTON de-icing features and icing restart functions remain unconfirmed and must be requested explicitly if needed.