Rovos' two aircraft were among the 30 or so produced as C-131D Samaritan transports. For more than 30 years they flew Air Force officials and provided medevac service. In the late 1980s they were retired to the Davis-Monthan Air Force Base storage facility in Arizona, and in 1991 they were transferred to the custody of the U.S. Air Force Museum in Dayton, Ohio (though the airplanes belonged to the museum, they stayed in Arizona). The museum swapped them for an airworthy Beech 18 owned by Long Island trader Bob Smirnow. In 1992, Smirnow sold the C-131s to Rolando Canedo, owner of Bolivia-based Líneas Aéreas Canedo.
Canedo ferried the aircraft to Bolivia and refurbished the interiors and added seats, replaced hoses and hydraulics, rebuilt the engines, and added GPS instruments. Because the airplanes were no longer owned by the U.S. Air Force, Bolivian aviation authorities certified them for airworthiness as Convair 440s. LAC operated the aircraft until 2001, when Canedo decided he might retire and sell the airplanes.
Just as Canedo was contemplating retirement, Rovos Rail was facing a crisis. Zimbabwe, through which Rovos ran its main route-Pretoria to the town of Victoria Falls-was crumbling under the rule of President Robert Mugabe's Zimbabwe African National Union-Patriotic Front and its campaign to redistribute white-owned land to poor blacks.
In March 2000, faced with problems operating the trains in Zimbabwe and widespread flooding in the region, Vos concluded that it was no longer wise to run a luxury train through the Zimbabwe countryside. He plotted a route from Pretoria through Kruger National Park and on to Pietersburg, followed by a final leg to Victoria Falls in a chartered DC-3 or -4. (After much tinkering, the trip now consists of rail legs from Pretoria to Kapama Game Reserve and then Kapama to Pietersburg, followed by a flight into Livingstone, on the Zambian side of the falls. Rovos offers the one-way journey weekly.)
Though the charters served admirably, Vos wanted an aircraft he could modify for luxury. He searched the trades and the Internet for airplanes that would match the nostalgic allure of his rail cars. His heart was set on a piston-engine airliner that was pressurized and powerful enough to fly over bad weather and take off in the heat and humidity that thinned the air in Africa. He also needed to carry 44 passengers-the capacity of one rail dining car and about the number of tickets to turn a profit on a run to Victoria Falls.
There wasn't much out there-just a few DC-4s, DC-6s, and the Convairs. He sent an engineer to Bolivia to evaluate LAC's two 440s, which he'd read about online. The engineer's report came back positive, and in May 2001 Vos personally inspected the airplanes.
To assure Vos that the airplanes could operate at altitude, LAC flew him on a round trip from its 8,360-foot-elevation base at Cochabamba to La Paz-at 13,325 feet, the world's highest international airport. Vos also insisted LAC crunch numbers for what he said might be a typical Rovos Air trip: "A flight from Johannesburg to Livingstone...which is 5,500-odd feet down to 4,000-odd feet at [95 degrees Fahrenheit] with 44 people." The calculations said the 440s could make the trip. "On the strength of that, I bought these things," says Vos. Two airliners, $1 million each.
Because the aircraft had flown only intermittently for the Air Force, and because they operated at altitude in Bolivia, the airframes were in good condition with almost no corrosion, but they were out of compliance with international airworthiness directives. Vos removed the airplanes' insulation and wiring, the avionics were again updated, and the instruments reconfigured and modernized.
One instrument that remained was the engine analyzer, a circular display near the flight engineer's seat. The flight engineer's main job, after starting the Pratt & Whitney R-2800 engines, is to monitor them during flight. "That instrument enables us to tell if the spark plug is firing or if the lead that's going into it is performing," says Theo Munro, a Rovos flight engineer who worked on DC-3s and DC-4s for 30 years in the South African air force. The analyzer can spot problems before they turn into real trouble. Its backlit sine waves pulse in synch with the engines and look like an electrocardiogram ("We often joke that that's the captain's heart rate," says Rovos Air operations chief Stuart Vere-Russell).
The Convair's signature system is its engine augmenter, which uses heat from the exhaust to warm outside air it has collected. The warmed air can be used to heat the cabin and de-ice the leading edges of the wings and stabilizers. In addition to warming the aircraft, the augmenter also helps cool the engines. It uses the vacuum induced by the high-speed flow of the exhaust gases as they pass through the exhaust tube to suck ambient air through the engine nacelles and reduce the need for cowl flaps. Convair boasted that the system added about 10 mph to cruising speed and 2,000 pounds of payload.