Which ECAM indicator status is always green during transit?

Which ECAM indicator status is always green during transit?

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

Answer: (A)

In ECAM, colors show how healthy or available a system is: green means normal, amber warning or fault would be shown otherwise. The APU bleed indicator tends to stay green during transit because the APU bleed circuit is a separate source of bleed air that, when the APU and its bleed system are healthy and not isolated, is considered available. It doesn’t depend on the engine bleed usage in the same way as the engine bleed lines do or as the air conditioning packs do. Engine bleed status can change with engine start, bleed valve isolation, or faults, so it’s not guaranteed to be green in flight. The left and right PACK indicators depend on the bleed sources and pack operation, which can be commanded on/off or shut down due to phase of flight, cooling demands, or faults, so they aren’t always green either. Therefore, the APU bleed is the indicator that is consistently green during transit when everything is healthy.

In ECAM, colors show how healthy or available a system is: green means normal, amber warning or fault would be shown otherwise. The APU bleed indicator tends to stay green during transit because the APU bleed circuit is a separate source of bleed air that, when the APU and its bleed system are healthy and not isolated, is considered available. It doesn’t depend on the engine bleed usage in the same way as the engine bleed lines do or as the air conditioning packs do.

Engine bleed status can change with engine start, bleed valve isolation, or faults, so it’s not guaranteed to be green in flight. The left and right PACK indicators depend on the bleed sources and pack operation, which can be commanded on/off or shut down due to phase of flight, cooling demands, or faults, so they aren’t always green either. Therefore, the APU bleed is the indicator that is consistently green during transit when everything is healthy.