Before working on landing gear, which procedure isolates energy sources and prevents unexpected re-energization?

• A. De-energize hydraulics
• B. Follow lockout/tagout procedures
• C. Chock wheels
• D. Wear PPE

Answer: (B)

Lockout/tagout procedures create a true zero-energy state before maintenance by identifying every energy source feeding the landing gear, isolating them, applying locks to prevent re-energization, and tagging the equipment to warn others. In landing gear work, energy can come from hydraulics, electricity, pneumatics, and stored mechanical energy. Simply shutting down one part, like hydraulics, doesn’t guarantee no energy will re-energize the system or that all sources are safely isolated. Lockout/tagout ensures all sources are blocked and clearly communicates that work is in progress, with verification that energy has been dissipated before maintenance begins.

De-energizing hydraulics alone is not enough because other sources may be present or residual energy still stored. Chocking wheels prevents movement but doesn’t address energy isolation. PPE is about personal protection, not stopping energy.