During the early hours of November 28, 1987, communication with South African Airlines (SAA) flight SA295, registration ZS-SAS, was lost. 

The aircraft, a Boeing 747 Combi, experienced a devastating in-flight fire in the cargo area before crashing into the Indian Ocean east of Mauritius, killing all 159 people on board. 

The incident would prove to be a complicated case, resulting in numerous debates and conspiracy theories, with certain aspects remaining unclear even to this day. 

Aircraft and loss 

The aircraft, named the Helderberg, was a modified version of the 747 that could transport both passengers and cargo in the main deck. Known as a ‘Combi’ (short for combination), the model included a moveable partition separating passengers from cargo, allowing airlines to be flexible when it came to the volume of cargo they transported.  

In a time of Apartheid political tension, SAA, the flag carrier for South Africa, was facing airspace restrictions over numerous African states. Confronted with having to fly longer routes such as the one taken by Flight 295, the versatile Combi proved to be an economical choice of transport for the airline.  

On the afternoon of November 27, at 14:23 Coordinated Universal Time (UTC), SAA 295 departed Taipei, bound for Johannesburg, South Africa with a stopover in Plaine Magnien, Mauritius. The flight had 140 passengers and six pallets of cargo on the main deck as well. A flight crew of 19 were also onboard the aircraft. 

At 23:48 UTC over the Indian Ocean, the captain contacted Air Traffic Control (ATC) at Mauritius Plaisance Airport and declared an emergency. The smoke alarm indicated that a fire had developed in the cargo section on the main deck. 

The last reported communication was at 00:04 UTC, November 28. All efforts by ATC to reestablish contact were to no avail.  

As day broke, the first signs of floating wreckage were spotted on the surface of the Indian Ocean. The Helderberg had been lost, leaving no survivors.  

Fire on the Helderberg and subsequent investigation 

Among the first sources of evidence were debris floating on the surface of the ocean. For example, the Republic of South Africa (RSA) report mentions two damaged wristwatches, which stopped at 00:07 UTC. The time shown on the broken watches suggests the impact occurred just four minutes after the last communication, indicating Heldeberg’s demise was sudden.  

The RSA report said some of the recovered items such as cabin paneling, furnishings and cargo showed traces of fire damage, such as heat discoloration and soot. In addition, scorched insulation wiring, a fire extinguisher with molten plastic on its surface and a melted graphite tennis racket all indicated an exceptionally fierce fire onboard, which had somehow originated in the main-deck cargo hold.  

The underwater wreckage was located on January 28, 1988. Remains from the passenger cabin of the rearmost galley along with the fuselage from the main deck cargo hold and a section of the rear pressure bulkhead all showed heat damage. Pieces of the forward left main deck cargo floor were also found to have accumulated melted aluminum and nylon on the upper surface, reinforcing suspicion of a fierce fire in the main-deck cargo hold that engulfed the flight.  

Dealing a blow to the investigation, the Flight Data Recorder (FDR) was not recovered. However, the Cockpit Voice Recorder (CVR) was and yielded evidence that the crew were aware of a fire on the main deck cargo hold. Moreover, the sound indicated the audio was being affected by the fire and ultimately disabled it.   

The cause of the fire remains a mystery 

The joint investigation by the RSA with aid from the National Transportation Safety Board (NTSB) and Federal Aviation Authority (FAA) concluded that the cause of the loss of SAA 295 was an in-flight fire, which eventually led to the plane crashing into the ocean.  

Investigators determined that the fire had originated in the main deck cargo hold. “From evidence pieced together it is clear that a fire commenced in the front pallet, on the right-hand side in the main deck cargo hold”, the RSA report stated. “The fire developed rapidly and could not be controlled”.  

According to the cargo log, SAA 295 was transporting six pallets of cargo, consisting of a mixture of electronic components including computer hardware, various paper documents, textiles, medicines and sports equipment.  

Evidence pieced together indicates that a fire commenced in the front pallet on the right-hand side (pallet N° PR) in the main upper deck cargo hold. The fire developed rapidly and could not be controlled. It generated smoke and carbon monoxide and carbon dioxide, some of which penetrated the passenger cabin and possibly the cockpit. Post-mortems indicated traces of soot in the victims’ respiratory passages, with carbon monoxide intoxication cited as a contributor in the cause of death 

Additionally, the fire caused a number of plastic supports for the insulation blankets to melt and damaged some of the blankets themselves. Such evidence reinforced the notion of the fire’s intensity and destruction. “The effects of the fire eventually led to the aircraft crashing into the sea”, stated in the RSA report.  

The report also criticized the Combi for its inadequacy in terms of fire protection for passengers. The exact source of the fire remains unknown.  

The RSA report concluded there was nothing in the cargo contents in pallet N° PR that could be described as dangerous goods. “Some of the computers consigned in pallet N° PR and other pallets were fitted with nickel-cadmium or lithium batteries, but under the circumstances those items were not likely to any ignition or explosion.” 

“The combustion included cardboard and plastic materials, but the actual source of ignition cannot be determined,” the report explained.  

“Nevertheless, the possibility of misdeclaration or even false declaration in the consignment notes of the cargo manifest cannot be ruled out completely,” the report continued.  

Given the political tensions at the time, the crash of flight 295 caused speculation about what had been put onboard the aircraft, something which persists today. The catastrophic in-flight fire on November 27, 1987, triggered multiple conspiracy theories and remains one of aviation’s great mysteries.