Occurrence Details
On 23 July 2024, at approximately 09:15 local time, a Boeing 737-800 aircraft registered P2-PXB and operated by Air Niugini Limited was preparing for a regular public transport flight from Jacksons International Airport in Port Moresby to Nadzab Tomodachi International Airport. During passenger boarding and cargo loading, a spill of mercury occurred in the aft cargo compartment (Cargo Hold No. 3). The aircraft had arrived from a previous flight at 08:41 and was being turned around for the next departure.
Cargo loading began at 09:00. A porter inside the cargo hold noticed a liquid spill on the floor and suspected it to be mercury. Loading was immediately halted. The source of the spill was traced to a 37-kilogram general cargo item declared as "excavator parts" under consignment number 656-41871701. Engineers confirmed the substance was mercury.
At the time, all 61 passengers, 2 pilots, and 4 cabin crew were on board. The pilot in command (PIC) was informed and subsequently made a public announcement that the flight could not proceed due to an unserviceable aft cargo compartment. All passengers disembarked with their personal belongings. The PIC switched off both air conditioning packs and notified company customer services via radio. Engineers retained the Aircraft Journey Technical Log and recorded the defect.
No injuries were reported among the crew, cargo handlers, or passengers.
Damage
According to the operator's internal safety investigation, an estimated 200 grams of mercury leaked from the package. The spill spread from the doorway of Cargo Hold No. 3 onto the compartment floor. No other damage was reported.
Aircraft Information
The aircraft was a Boeing 737-800 equipped with lower cargo compartments designed to meet FAA Class C compartment requirements. These compartments are sealed and pressurized but lack fresh air circulation and temperature control, unlike the passenger cabin. A pressure equalization valve is installed in the aft bulkhead to maintain pressure balance, and blowout panels provide pressure relief in case of depressurization.
Personnel Information
The PIC held a valid PNG Airline Transport Pilot License and had endorsements for single- and multi-engine aircraft, including the B737 (300-900 series). His medical certificate was current with a limitation requiring spectacles. Training records showed valid B737 Safety and Emergency Procedures and Dangerous Goods Awareness certificates at the time of the occurrence.