Soaring Skies to Searing Rails

Aermacchi MB326 of the South African Air Force

Steven McLean – Impala in flight

At 400 km/h and 100 feet above the Atlantic Ocean, Cape Point was filling the windscreen of the jet very fast.

‘I’ve got her.’ the instructor said from the rear seat.

He pushed the throttle forward and felt a punch in the back as the Viper engine responded. The Impala trainer soared over the mythical tip of Africa and in seconds they were screaming over the city of Cape Town.

At four in the morning, on a bitterly cold snowing winters day the New York Metro Transit Authority (MTA) maintenance engineer moved the snow blower onto the rail yards’ main line and pushed the button to start the Viper engine mounted on the front of the unit. Through the sound proofing he heard that same whine that the two pilots had heard 46 years earlier in a sun filled African sky.

Viper

In the immediate aftermath of World War II the British government were keen to take advantage of technological advancements made during the war. They established a joint missile technology development agreement with Australia whereby the Australians would provide test facilities and the British would develop target drones.

Armstrong Siddely created a short life jet engine for the Jindivik target drone, which was the forerunner of the Viper series of jet engines. Built to run for only 14 hours, the first tests in 1951 promised great things and the basic design was upgraded beyond the wildest dreams of the pioneers of the British jet industry. Although production of the drone ceased in 1986, the Jindivik is still the standard UK target drone with over 502 aircraft produced.

The Viper was the U.K.’s first post-war attempt at the design and production of a relatively inexpensive, simple turbojet. Mergers and consolidation saw the Viper produced later by Bristol Siddeley and finally Rolls Royce.

Additionally it was licensed for manufacture in a number of countries; India for the Kiran, Romania for the Orao and IAR99, Yugoslavia for the Galeb range and others, Italy for the MB326, MB339, and PD 808, Brazil, Australia and South Africa for the MB326, a single engine two-seat jet trainer and light attack aircraft produced by Aermacchi, today Alenia Aermacchi S.p.a.

Probably the longest production aircraft engine in the business, in total 5727 units were built of which 334 were made in South Africa.

In the early 1960s the South Africa Air Force began a process of modernisation and used this program as a springboard for the establishment of an indigenous aircraft industry under the name of Atlas Aircraft Corporation.

The Aermacchi MB326 was the first aircraft manufactured under license. It was powered by the Viper 11 Mk.22/1 engine, initially supplied by Piaggio who built the Viper at their factory in Finale Ligure near Genoa, Italy. Subsequently Atlas assembled most engines from Piaggio-supplied kits.

Sixteen MB326 airframes, known locally as the Impala, were imported for assembly at Air Force Base Ysterplaat Cape Town. The first one numbered 460, was officially handed over on 3 June 1966. An additional 30 kits were delivered and after that the fledgling South African aviation industry produced a further 105 dual seat and 100 single seat Impala aircraft.

These aircraft were used as primary jet trainers and as light attack fighter. It had many advantages over high performance jets. Although slower, it could operate from primitive, short airfields and was a tough little plane.

It became well known with the public as the mount of the superb Air Force aerobatic team the Silver Falcons with which it served for 30 years.

On retirement some aircraft were sold to Brazil, others in the United States and one or two into private hands and to museums. A large number were scrapped and in some cases the long lasting Viper 11 Mk.22/1 engines were sold on separately.

The Metro

During the summer of 2011 the Metro Transport Authority rebuilt three jet-powered snow blowers. The main new feature of the blowers was the high efficiency Rolls Royce Viper aircraft turbine engines used for melting snow. These units produce exhaust gases measuring 600 degrees Fahrenheit, which virtually vaporizes snow.

The MTA press release highlights the benefits of the new equipment.

‘"If the jets do the job right, all you see is steam coming off the steel," said Peter Hall, Foreman of the Maintenance of Way Equipment Shop in North White Plains. "They produce 2,500 pounds of thrust, which makes them very good at getting under heavy, wet slush, ice and crusty snow."

The Rolls Royce turbines use half the fuel of the engines they replace, 1950s-era General Electric/Westinghouse J57 turbines that were used in B-52 bombers.

"With fuel tanks that hold 1,800 gallons, these new jet blowers can run continuously without having to stop to refuel in the middle of a storm," Hall said.

These turbines produce less smoke, "spool up" (get up to speed) quicker, run cooler and are more reliable than the one they replaced.The turbines have directional controls that allow the operator to point the turbine's 600F degree exhaust straight ahead or sweep from side to side. This specialized, self-propelled, 30,000-pound, rail vehicle travels no more than 30 miles an hour to move from place to place, but much slower when the jet engine is engaged.

The turbines make noise (imagine an airport runway) so the operator's cab has sound-deadening insulation and ear protection is required. This is one reason these machines are intended for use in the rail yards and remote locations. In densely populated areas, the railroad relies on cold-air snow blowers.’

It is extremely important for the MTA to maintain reliable and above all safe commuter services for their customers. Their New York City Transit's Department of Subways maintains a fleet of snow and ice-busting equipment which are tasked to keep the tracks and most significantly the third rail which delivers the power, clear of snow and ice during harsh winter weather.

The fleet includes super-powered snow throwers, jet-powered snow-blowers, and specially-built de-icing cars, all designed to keep service moving. The judicious use of this equipment allows more trains to run which in turn keep the tracks used and clear of snow.

The last Impala flew in in November 2005, but the heart of the little jet lives on with the MTA.

MB326 on the production line

Viper motor as used by the MTA

Photographs

Steven McLean – Impala in flight

John Miller – Impala in production

MTA - Snowblower

Acknowledgements

Emilio Gravano Piaggio Aero Industries S.p.A.

Giulio Valdonio, Italy

Stanislaw Dabrowski, MTA New York

Barbara Buzio Alenia Italy

Olie M. Ericksen, OLIE ERICKSEN, INC. Pennsylvania, USA

Wynand Breydenbach and Martin Laubsher Denel Aviation South Africa

Page updated

Google Sites

Report abuse