Question 13 UFIV02 - Assistant Engineer - UFIV

The Correct Answer is C **Explanation for C (Correct Option):** The lubricator reservoir bowl should be re-filled with clean oil when it becomes approximately half full, as visible in the sight glass. This proactive maintenance practice ensures a continuous supply of oil to the air-starting motor. Allowing the oil level to drop too low increases the risk of the lubricator assembly sucking air instead of oil, which can lead to oil starvation and damage to the vanes and internal components of the air-starting motor. Refilling at the halfway mark (or a similar conservative level) provides a necessary margin of safety and prevents unnecessary wear and tear. **Explanation of Incorrect Options:** * **A) The lubricator reservoir bowl should be re-filled with clean oil when the level is no longer visible in the glass.** This is incorrect because waiting until the oil level is no longer visible means the system may already be running dry or very close to it. This increases the immediate risk of air ingestion into the oil line and subsequent damage to the air motor. * **B) The lubricator reservoir bowl should be re-filled with clean oil as soon as the level drops to the very upper part of the glass.** While frequent refilling is better than letting it run dry, refilling immediately after a slight drop (the very upper part) is overly cautious and unnecessary. Standard maintenance practice focuses on maintaining a sufficient reserve (like half full) rather than constantly topping off, which provides adequate safety margins without requiring excessive attention. * **D) The lubricator reservoir bowl should be re-filled with clean oil when it is estimated that the bowl is completely empty.** This is dangerously incorrect. Allowing the bowl to become completely empty guarantees that the air motor will operate without lubrication, leading to rapid component wear, catastrophic failure of the vanes, and significant repair costs.