What must be done before performing any aircraft fuel cell maintenance?

Before performing any aircraft fuel cell maintenance, it is essential to first download all explosives. This step is crucial for ensuring safety, as it prevents any accidental ignition of volatile materials that could pose a significant risk during maintenance work. Fuel cells contain flammable substances, and disconnecting or removing explosives minimizes the risk of explosions or fires.

Other considerations, such as checking fuel levels, performing visual inspections, or testing fuel integrity, are important in their own right but do not address the immediate and critical safety concern surrounding potential explosive hazards that exist during maintenance operations. Therefore, prioritizing the removal of explosive materials is vital to safeguarding personnel and equipment in the maintenance environment.