Which of the following ECAM valve indicators always displays green (does not display amber during transit)?

Which of the following ECAM valve indicators always displays green (does not display amber during transit)?

• A. APU bleed
• B. Engine bleed
• C. Left PACK
• D. Right PACK

Answer: (A)

ECAM valve indicators show the valve’s position and whether it is moving. Green indicates the valve is in the commanded position and stable, while amber flags that the valve is in transit or cycling between positions. The APU bleed valve is designed so its ECAM indicator does not show amber during movement; it stays green when the valve is in the appropriate state for APU bleed operation. In contrast, engine bleed and both PACK valves can display amber while they are moving to meet changing bleed/pack demands, so they are not guaranteed to stay green during transitions.

ECAM valve indicators show the valve’s position and whether it is moving. Green indicates the valve is in the commanded position and stable, while amber flags that the valve is in transit or cycling between positions. The APU bleed valve is designed so its ECAM indicator does not show amber during movement; it stays green when the valve is in the appropriate state for APU bleed operation. In contrast, engine bleed and both PACK valves can display amber while they are moving to meet changing bleed/pack demands, so they are not guaranteed to stay green during transitions.