Two Consignments, One Hold
A narrow-body freighter is loading at a regional airport. The load plan places a pallet of UN1263 Paint (Class 3, packing group II) in the forward hold and a pallet of UN1942 Ammonium nitrate (Class 5.1, packing group III) in the aft hold. Both are in non-refrigerated compartments. The loader notes that the aft hold also contains a small package of UN3480 lithium-ion batteries. The captain's loading instruction shows no segregation requirement between these items because the load planner treated them as unrelated commodities. Ambient temperature on the ramp is 38 degrees Celsius. The loading supervisor must decide whether to sign off the load sheet.
1. Evaluate the segregation and loading decision, identifying which combinations require action and why.
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The load planner's assumption that the items are unrelated is the core error. Segregation is driven by hazard class and subsidiary risk, not by commodity description.
Analysis:
- Class 3 versus Class 5.1. Flammable liquids and oxidizers are incompatible. An oxidizer increases the intensity of a fire involving a flammable liquid. On a freighter with separate holds this may be acceptable only if the compartments are effectively separated and the operator's segregation standard permits it; the supervisor must verify against the operator's dangerous goods segregation table rather than assume.
- Class 5.1 versus Class 9 lithium batteries. Ammonium nitrate is an oxidizer that can accelerate thermal runaway in lithium cells. The small battery package in the same aft hold as the oxidizer is the highest-risk pairing on this aircraft and should be separated or removed.
- Temperature. At 38 degrees Celsius ambient, ammonium nitrate and flammable liquids are both sensitive to heat. The supervisor should confirm hold temperatures and whether any package is temperature-controlled.
- Documentation. The load sheet must reflect the actual segregation applied; a load sheet showing no requirement is itself a finding.
Action: Do not sign off as presented. Separate the lithium package from the oxidizer, verify Class 3/5.1 separation against the operator's table, and correct the load sheet.
2. Describe how the supervisor should document and escalate the discrepancy, and what records should be retained.
Read the worked answer
The discrepancy is both a loading error and a documentation error, so the response has two tracks.
Immediate escalation:
- Halt loading and notify the captain and the operator's dangerous goods post-holder before any further cargo is placed.
- Record the finding in the loading discrepancy log with time, location, package identifiers, and the person who identified it.
- If the aircraft has already been loaded, offload or reposition before departure; do not rely on a verbal instruction.
Documentation:
- Amend the load sheet and the loading instruction to show the segregation actually applied, signed by the person making the change.
- Retain the original load plan showing the error, since destroying it undermines the investigation.
Records to retain:
- The dangerous goods transport documents and acceptance checklists for both consignments.
- The corrected load sheet and the discrepancy report.
- Names and roles of personnel involved and the training records confirming their competence.
Follow-up:
- Raise a corrective action on the load planning process, since the root cause is a systemic failure to apply segregation rules, not a single loader's mistake.
- Feed the finding into the quality assurance review so trends can be tracked.