Immediately after an engine has started up, what is the first instrument reading to be checked?

The first instrument reading to be checked immediately after an engine has started up is oil pressure. This is crucial because oil pressure is vital for ensuring that the engine’s moving parts are adequately lubricated. Insufficient oil pressure can indicate that the oil pump is not functioning correctly or that there is a problem with oil circulation, which could lead to serious engine damage.

Monitoring oil pressure soon after startup helps confirm that the lubrication system is operational, which is essential for the engine's performance and longevity. While checking battery volts, gyro erection, or vacuum levels is also important in the overall operation of the engine, ensuring proper oil pressure immediately after startup takes precedence due to its direct impact on engine health.