General Authority of Civil Aviation (GACA) Aeronautical Information Publication (AIP) Practice Exam 2026 - Free GACA AIP Practice Questions and Study Guide

The illumination of the "BRAKE SOURCE" light is specifically triggered by a loss of both the right and center/reserve hydraulic systems. In an aircraft, the brake systems typically rely on multiple hydraulic systems to function properly. If these crucial systems experience failure, it indicates that there is insufficient hydraulic pressure available to operate the brakes effectively, which is a critical safety concern for the aircraft's operation. The "BRAKE SOURCE" light serves as an essential alert to the pilots, informing them that the backup hydraulic systems are compromised, and action must be taken to ensure safe operation.

The other options do not trigger the "BRAKE SOURCE" light. While a loss of the left hydraulic system could affect brake function, it would not necessarily illuminate this specific warning light. Similarly, a failure in the parking brake system pertains to a separate function within the brake operation that would not activate this light. Lastly, under normal operation of the brake systems, the "BRAKE SOURCE" light should remain off, as it indicates that all hydraulic systems are functioning as required.