Why Are Legacy Aircraft Fuel Gauges Notoriously Inaccurate?

Answer can be traced to a combination of multiple things—corrosion, latency, and time.

FLYING Staff

Wednesday, December 11, 2024 at 11:02 AM ET

Verified

Edited By: tccjeremy

Key Takeaways:

Legacy aircraft fuel gauges are notoriously inaccurate due to corrosion from fuel moisture and dissimilar metals, wear from extended periods of stagnation, and stress from abrupt flight movements, all compounded by the age of the original components.
This inaccuracy poses a significant safety risk, contributing to fuel starvation accidents, which are a leading cause of incidents.
Upgrading legacy aircraft with modern, corrosion-resistant digital fuel level sensors and compatible gauges is highly recommended as a critical safety improvement to prevent fuel starvation.

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Question: Why are legacy aircraft fuel gauges notoriously inaccurate?

Answer: It is the combination of multiple things—corrosion, latency, and time.

There is always trace amounts of moisture in fuel, and it produces compounds that are corrosive. While most of the aircraft is aluminum (which is lighter and less susceptible to corrosion), steel is used in specific applications (such as older fuel senders) because of its conductive qualities and low cost.