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Module 5. Digital techniques / Electronic instrument systems

When removing a PC card from an ESDS assembly ensure a low current path between

  • aircraft and ground.
  • you and the assembly.
  • you and the aircraft.

Explanation

When withdrawing a PC card you bond yourself to the aircraft so both sit at a common potential and only a low, controlled current can flow as the card is removed. Equalising with the aircraft structure prevents a static difference between operator and airframe from discharging through the sensitive card.

Stavros asking:

Why isn’t B the correct answer

Community Comments (1)

D
Devraj_S Posts: 6 05.06.2026 / 09:30
The correct option is C. When the card is removed while still installed, you must sit at the same potential as the aircraft structure the assembly is referenced to, so any static charge bleeds away through a controlled low current path instead of discharging through the sensitive component; bonding only to the assembly leaves both of you floating relative to the airframe. Refer to Module 5.12 electrostatic sensitive devices, where grounding personnel to aircraft structure is the specified precaution.

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