Protective cover, radiation shield and test unit for helicopter blade crack indicator

In a cover for protecting and resetting a pressure sensor for use when the sensor is not in service, the sensor providing for indicating cracks in a hollow aircraft blade, the sensor having a shaft carrying a radiation source, with the sensor shaft sliding in a sensor housing between a first position with the radiation source within the housing and a second position with the radiation source external of the housing,

• the improvement in the cover comprising:
• a sleeve for slidably positioning around the sensor housing and removing from the sensor housing, said sleeve having an open end for engaging a stop of the sensor and having a closed end spaced from the sensor out of engagement with the sensor when said open end is engaging said sensor stop;
• and
• a plunger slidably mounted in said closed end of said sleeve and movable between an outer position and an inner position, said plunger and sleeve having interengaging means for retaining said plunger in said sleeve closed end, with said plunger out of engagement with the sensor shaft when in said outer position and engaging the sensor shaft when in said inner position to move the sensor shaft manually into the sensor and reset the sensor;
• with said sleeve being of a material absorbing the radiation of the source.