Comment It's the emergency power system (Score 1) 216
that's hazardous. Until safed on the ground, 500 foot clearance is required.
""hazardous chemical spill related to the plane crash,""
"What is Hydrazine?
Emergency Fuel: F-16s use an H-70 blend (70% hydrazine and 30% water) to power the EPU.
Automatic Activation: The EPU turns on automatically if the main engine fails in flight. It provides emergency electrical and hydraulic power so the pilot can keep control of the jet.
Toxic Risk: Hydrazine is a highly toxic and corrosive chemical. Exposure to liquid or fumes causes skin burns, dizziness, respiratory distress, and other severe health hazards. Crashes involving an active EPU often require hazmat teams to decontaminate the area."