What happens when the Pt2 probes become unblocked during takeoff?

When the Pt2 probes, which are responsible for measuring total pressure in jet engines, become unblocked during takeoff, the expected outcome is that the Engine Pressure Ratio (EPR) readings will stabilize to reflect the actual performance of the engine.

Initially, if the Pt2 probes are blocked, they may give skewed or incorrect pressure readings, which would lead to inaccurate EPR calculations. This could result in incorrect engine thrust settings and potentially mislead flight engineers and pilots regarding engine performance. Once the probes become unblocked and are able to measure total pressure accurately, the EPR readings will adjust to show the true engine performance, thus stabilizing the thrust levels to correspond with actual engine output.

In contrast, when probes are blocked, thrust settings could be unstable or inaccurately reported, leading to inconsistent thrust levels. This effect would not be seen when the probes are functioning correctly. Similarly, significant drops in all engine parameters or sharp increases in engine temperature would not directly relate to the unblocking of the Pt2 probes but instead would represent other mechanical or operational issues that could arise during flight. The primary effect of the probes unblocking is the return to accurate and stable EPR readings.