Boxes Marked "Empty" — Fire in the Hold Over the Everglades

ValuJet's heavy-maintenance contractor SabreTech was replacing expired and near-expired chemical oxygen generators on MD-80s. From about mid-March 1996 crews removed roughly 144 generators; the work cards were signed off on 30 April and 5 May. An unexpended chemical oxygen generator is a live pyrotechnic device: pull the lanyard and it burns at hundreds of degrees making oxygen. The required plastic safety caps were never installed — mechanics signed the cards anyway — and the generators were tagged with the wrong parts tags, boxed with bubble wrap, and staged as if they were ordinary stock. Days before the accident the boxes were prepared for return to ValuJet as company material: five boxes described on the shipping ticket as "Oxy Cannisters - Empty," with no hazardous-materials markings. Loaded into the forward class D cargo compartment of Flight 592 — a hold with no fire detection and no suppression — one or more generators actuated, ignited the packaging around them, and the DC-9 crashed into the Everglades ten minutes after takeoff.

This is the corpus's hardest lesson about where a maintenance task ends: not at the sign-off, but at the safe disposition of everything the task removed. Every handoff after the wrench — tagging, packaging, labeling, shipping — is still maintenance, and each false word on a tag traveled forward until it put live oxidizers under a passenger cabin. The NTSB found the failure of SabreTech to properly prepare, package and identify the unexpended generators causal to the accident, alongside ValuJet's oversight of its contractor and the FAA's failure to require fire protection in class D holds.

1. Treat removed energetic or hazardous components as live until rendered safe — an unexpended oxygen generator is a hazmat item, not a spare part.
2. Install the safety caps (or expend the generator) before it leaves the aircraft's side; never sign a step that was not done.
3. Tag honestly: the tag's condition status must match physical reality, and "empty" is a measurement, not a hope.
4. Package and label per the hazmat regulations, with trained shipping personnel — maintenance's paperwork is the only truth the ramp will ever see.
5. Anyone in the chain — mechanic, stores, shipping, ramp — who cannot verify what is in the box has the duty to stop it.

Frequency of hazmat-mislabeled maintenance shipments is not quantified in public sources; the NTSB documented the systemic gaps — undeclared hazardous materials carried as company material — in this report and the industry's recurring-error canon keeps fitting-of-wrong-parts and mishandled components at the top of maintenance occurrence lists (UK CAA CAP 716, Table 2).

Activation of one or more chemical oxygen generators in the forward cargo compartment initiated the fire; the class D hold had no smoke detection, so the crew's first warning came minutes into the flight. The aircraft crashed into the Everglades at high speed; all 110 aboard died; the airplane was destroyed (NTSB AAR-97/06).