If the magnetic oil drain plug detects metal particles, will a cockpit chip light illuminate to warn the pilot?

• A. Yes
• B. Maybe
• C. Not necessarily
• D. No

Answer: (D)

A magnetic drain plug is a passive device. It simply collects ferrous metal particles as oil flows by; it does not contain any sensor or wiring to send a signal to the cockpit. Because there’s no electronic signal from the plug itself, it cannot cause a cockpit warning light to illuminate on its own.

If there were an active sensor—like a chip detector integrated into the oil system and wired to the cockpit—then metal particles detected in the oil could trigger a warning. But the magnet on the drain plug alone doesn’t provide that signal. So, the absence of a light from simply the drain plug is expected; you’d rely on actual sensor hardware to set off a warning.

In practice, you’d visually inspect the drain plug for metal debris and follow maintenance procedures if metal is found, since metal particles indicate wear somewhere in the engine.