A carbureted 172 over the Alaska coast, in rain, with the carb heat knob pulled halfway
On the evening of September 21, 2025, over the Alaska coast, an unplanned headwind and deteriorating weather with precipitation push you to divert to an alternate airport.
The alternate is reporting cool, wet, near-saturated air.
To hold the cylinder temperatures where you want them in the cool air, you've had the carburetor heat control pulled partway out — not full, not off.
On approach to the alternate, the engine RPM begins to fall — smoothly, steadily, over three or four seconds. It sounds like the engine is running out of fuel.
The engine RPM is winding down. What do you do first?