What should a pilot first suspect if there is no power turbine reading on a cold day startup?

When a pilot observes no power turbine reading during a cold startup, the first suspicion should be power turbine tips rubbing. This scenario often occurs because, in cold conditions, the thermal expansion of components is not yet at equilibrium. The components, including the turbine tips, may not have sufficiently cleared their designated clearances, leading to the tips coming into contact with the casing. This rubbing can prevent the proper rotation of the turbine, which would be reflected as a lack of power turbine reading on the instruments.

Recognizing this issue is crucial, as it can lead to significant engine damage if the engine is operated under these conditions. Addressing any signs of rubbing before further operation is essential to prevent costly repairs and ensure safety. The other options relate to different operational conditions; fuel blockage would typically show other symptoms, electrical connections would likely cause a total instrument failure, and low oil pressure would affect engine performance significantly before reaching the startup phase.