What happened
On the morning of 15 January 2025, a Beechcraft King Air 200C, registered ZS-PEA, departed Chief David Stuurman International Airport (FAPE) bound for O.R. Tambo International Airport. The aircraft was operating a commercial cargo flight, carrying various quantities of powdered and liquid chemicals packaged in boxes and 25-litre containers.
While cruising at flight level 220, a flight courier seated in the rear cabin reported hearing a popping noise originating from the cargo area, immediately followed by an unusual odor. The crew reacted quickly by donning oxygen masks. The first officer declared a MAYDAY and requested an emergency descent to flight level 100. The aircraft returned to FAPE and landed safely, where a specialized hazardous materials team was called to assist with the offloading process.
The investigation
The SACAA AIID investigation focused on the source of the odor and the handling of the dangerous goods. Investigators found that the cargo, which included flammable materials, had been loaded such that the crew had to climb over boxes to reach the cockpit. One specific box containing flammable material had been placed in the aircraft lavatory.
Upon inspection of the cargo by the HAZMAT team, all containers and boxes were found to be structurally intact with no visible leaks or spills. While the crew reported experiencing itchy eyes and throat irritation, medical personnel eventually cleared them of any serious injury. The investigation also noted that the notification to captain (NOTOC) documentation lacked required signatures from both the shipper and the captain.
Findings
- The aircraft was airworthy and properly maintained at the time of the incident.
- The crew followed emergency procedures by using oxygen masks and initiating an emergency descent.
- A chemical smell in the cockpit and cabin area was the primary driver for the emergency return to airport.
- The origin of the chemical odor could not be identified, as no leaks were found in the cargo.
- The cargo loading configuration obstructed the walkway, and the use of the lavatory for flammable cargo storage was noted as improper.
Safety action
Following the investigation, two safety recommendations were issued to the operator:
- The operator should clearly mark cargo load areas and maintain an unobstructed walkway in the cabin.
- Proper, purpose-built storage solutions should be implemented for segregated dangerous goods, as the lavatory is not an appropriate storage location.
- The operator should provide all crew members with specialized personal protective equipment (PPE) relevant to the types of dangerous goods being transported, ensuring it is readily available for emergencies.