Choose a control that changes the hazard path: During night…

Chооse а cоntrol thаt chаnges the hazard path: During night maintenance, a technician can mistakenly open the adjacent fuel-system valve because two identical controls are mounted side by side. Four feasible options are available: add a caution to the manual; provide recurrent training; add a guard and distinct control shape; or redesign the panel so the valves cannot be confused. Choose the highest practical option in the safety order of precedence and explain one verification activity and one remaining limitation or dependency.