South African Civil Aviation Authority- (SACAA-) approved aircraft modifications design organisation Challenge Air has successfully fitted a forward-looking infrared (FLIR) system to a Robinson R44 helicopter belonging to the Protea COIN security company. (The FLIR was manufactured by US company FLIR Systems.) This project was carried out under the current Supplementary Type Certification (STC) system, mandated by the SACAA in 2011.

“Protea COIN approached us about two years ago to do this work,” reports Challenge Air head of engineering Mike Piksa. “We worked closely with the SACAA and we have an excellent relationship with them. The SACAA were very strict and had to oversee all the tests.”

There were two aspects to the fitting of the FLIR system to the helicopter – avionics and structural. “The avionics side was reasonably simple,” says principal engineer: avionics and electrical Gary Bernstein. “It involved proving that the aircraft had enough electrical supply to support the system and then integrating the system to the aircraft electrical supply. “No STC was required, but we did do a complete load analysis of the aircraft’s electrical system and proved that there was more than enough electrical power to support the FLIR system.”

More work was involved on the structural side. A bracket to mount the FLIR monitor had to be designed and installed in the cockpit. On an aircraft, this is not a simple job. The bracket had to be padded to avoid injury to aircrew in the event of an accident. It had to be subjected to static tests before being installed in the helicopter. And it had to meet various statutory require-ments, including the ability to withstand heavy landings and emergency landings. In addition, the mounting for the FLIR system itself had to be fitted to the outside of the fuselage.

“We also had to install an electronic control unit (ECU) in the rear of the cabin. We needed to develop a false floor to accommodate it,” explains principal engineer: structures Kavita Vanmari. “And we had to make provisions to accom-modate the installation of the wire looms to link the FLIR, the ECU and the monitor. “We had to cut out sections of the airframe to do this and we had to reinforce the structure in compensation. “We also had to do conduct flight tests after the installation to ensure the vibration levels were acceptable. We had to draw up the flight test programme. All the static and flight tests were monitored by the SACAA. Our installation didn’t affect the weight of the aircraft significantly – everything is within limits.”

The installation of the Flir systsem and associated equipment required continuous trial fitments and all changes had to be approved by Challenge Air chief design engineer Clinton Bridgelall. The project was closely monitored by company structural engineer Vishaal Bhana, who was in constant liaison with the SACAA.

The FLIR allows the helicopter to operate effectively at night and in bad weather. Operated by a crew of two, its missions include the escort of armoured trucks carrying cash and/or other valuable assets. “We also use the helicopter and the FLIR system to hunt for suspects and to support the [South African Police Service],” states Protea COIN helicopter operations manager and chief pilot George Tonking. “Our company also supports community policing and uses the helicopter for this, whenever possible. The FLIR works very well – the system has excellent definition. It is also fitted with a [global positioning system] and a laser pointer. It’s a very good tracking system. The R44, which is owned by us, is very reliable, very safe, very economical.”

Challenge Air can undertake avionics, electrical, electronic and structural modifications on aircraft. It has installed antennas and light detection and ranging (Lidar) systems on aircraft. (Lidar is an airborne remote sensing technology that uses light pulses from a laser to precisely measure the distance from an aircraft to the ground, thereby building up very accurate three-dimensional data about the shape and surface characteristics of the terrain being overflown.) The company has also extensively modified and installed aerial delivery systems on Lockheed Martin L-100 Hercules aircraft (the civil version of the C-130 military airlifter). These allow pallets loaded with emergency supplies to be easily parachuted out of the rear of the aircraft.

In addition, Challenge Air can design helipads and consults on cash investigations and maintenance. It also assists with repairs. “Our primary goal at the moment is to get all the necessary paperwork approved by the SACAA to allow us to become ‘SACAA-designated engineering representatives’,” reports Piksa. “This status would allow the company to approve or recommend approval of technical data to the CAA.

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