aircraft. Fred Bereswill, the investigator from Boeing, characterised the Flight 295 fire as significant for this reason. Barry Strauch of the NTSB visited Boeing's headquarters to inquire about the Combi's design. Boeing's fire test in the Combi models did not accurately match the conditions of Flight 295's cargo hold; in accordance with federal US rules, the Boeing test involved setting a bale of tobacco leaves ablaze. The fire stayed within the cargo hold. The air in the passenger cabin was designed to have a marginally higher pressure than cargo area hold, so if a crew member opened the door to the cargo hold, the air from the passenger cabin would flow into the cargo hold, stopping any smoke or gases from exiting through the door. Investigators devised a new test involving a cargo hold with conditions similar to the conditions of Flight 295; the plastic covers and extra pallets provided fuel for the fire, which would spread quickly before generating enough smoke to activate smoke alarms. The hotter flame achieved in the new test heated the air in the cargo hold. This heated air had a higher pressure than normal, and overcame the pressure differential between the cargo hold and the passenger cabin. When the door between the passenger and cargo holds was open, smoke and gases therefore flowed into the passenger cabin. The test, as well as evidence from the accident site, proved to the investigators that the 747 Combi's use of a class B cargo hold did not provide enough fire protection to the passengers. The US Federal Aviation Administration (FAA) confirmed this finding in 1993 with its own series of tests. After the accident, SAA discontinued use of the Combi and the FAA introduced new regulations in 1993 specifying that manual firefighting must not be the primary means of fire suppression in the cargo compartment of the main deck. Complying with these new standards required weight increases, which made the 747 Combi no longer viable. Nevertheless, the Combi remained in the 747 product line up until 2002, when the last 747-400 Combi was delivered to KLM. Conspiracy theories regarding the cause of the fire In January 1992, the journal of the Royal Aeronautical Society (RAeS) reported that the inquiry into the in-flight fire that destroyed Flight 295 might be reopened because SAA had allegedly confirmed that its passenger jets had carried cargo for Armscor, a South African