MHS Aviation, which primarily operates to oil and gas rigs in the South China Sea, is stepping up trials of the Swedavia-developed Global Positioning & Communications (GP&C) system and plans to use it on its entire helicopter fleet. MHS Aviation initially installed a system on a Sikorsky S-61 in September 1994 - the first time the system was installed in a helicopter - and, since then, it has been installed on a further S-61 and an S-76. All three helicopters are being flown from Kerteh to rigs in the South China Sea.

The GP&C uses automatic dependence surveillance (ADS) reports, together with a datalink in a future-air-navigation-system type of application for use in airborne and land-based units. MHS is able to use the system to track the position of helicopters to the furthest rig it services - 240km (130nm) from the coast. Data reports are sent through line-of-sight VHF links, with one repeater station on a rig 180km offshore.

"Without this system, our pilots have to call back to base every ten minutes to make verbal position reports; now we can track them precisely without the need for the pilots to keep calling," says Syed Abdul Rahman Alhadad, engineering manager at MIIS Aviation.

"We are planning to install transponders on all our helicopters which are in daily use. Those which are on ad hoc charter will probably only have the antenna racks and wiring put in. A transponder can be fitted and programmed when that helicopter needs to fly," he says.

So far, MHS is using the system only to track its helicopters from the base station on Kerteh. The installation of GP&C cockpit displays will give pilots, as well as ground controllers, full situational awareness.

Syed says that a cockpit display will be installed for evaluation on the S-61 as soon as temporary certification has been received - probably early in 1997. Pilots will then be able to use the touch-screen to communicate through datalinks with the ground controllers, to create flight plans, to perform precision approaches to rigs, and also to view the position, heading, altitude and speed of all other equipped helicopters in the area of coverage.

Source: Flight International