Freighter to Passenger Conversion

Contribution by Chris Bester

In the mid-1970s the Safair board had taken the decision to expand the fleet of commercial 

L382 series from eight to sixteen aircraft. They had also decided to convert four of these new aircraft from freighters into passenger configurations.

At the time, I was working in the United States as the Safair representative taking acceptance of the new aircraft and project managing the conversions.

After acceptance of the new aircraft by Safair crews, 4 of the aircraft had to be flown to 

New Braunsfield Airport near San Antonio Texas for conversion. The modifications were done by Ventura Company.

The modification basically comprised of cutting 3 holes into the side and above the floor level of the aircraft on each side of the airframe, and strengthening the airframe area surrounding each hole. These holes were to be escape hatches.

These modifications had to be approved by the USA Federal Aviation Authority before release. The modifications also included 101 passenger seats that were mounted on seven cargo pallets that operated on a roll-in-roll-off system. There was also an eighth pallet that was positioned on the ramp and served as a toilet cubicle. Inside all normal notices and alarms were fitted.

One of the FAA requirements was that the aircraft structure and sealing around each escape hatch had to withstand the pressure differential as applicable at maximum cruising altitude.

The first modified aircraft flew back to the Lockheed factory where it was pressurized up 

in the presence of FAA, Lockheed, and Safair staff. After a lengthy period of pressurising the aircraft and almost getting to the required pressure differential the lunch siren blasted and the lady operating the pump immediately shut it down and left for lunch. 

There was no non-return valve so the pressure simply decreased again. Despite requests from the audience that the process not be interrupted, the Lockheed management shrugged their shoulders and cited local Labour Laws.

After lunch, the process was resumed and after a number of hours the pressure differential was finally reached allowing the aircraft to pass the test.

When the first modified Herc arrived in South Africa, evacuation tests under the supervision of the South African Civil Aviation Authority, which in those days was designated as the DCA (Division of Civil Aviation), had to be conducted. Documentary compliance with all the US Federal Aviation Authority rules also had to be submitted and be proven.