The South African Air Force (SAAF) has displayed for the first time two Denel Oryx helicopters, separately fitted as communications interception (COMINT) and jammer platforms.

The jammer aircraft is fitted with twin flat antenna arrays mounted sideways across the cabin on a steerable platform supported on air-cushion bearings. The main jammer array operates in L-band with the secondary array in S-band. The helicopter's side doors have been replaced by sliding blisters enabling steering of the antenna across an arc of around 110¹. The system is claimed to have an output capacity of up to 80Mhz but is about to be upgraded.

The system was developed by little-known South African electronic warfare specialists Sysdel, which also developed equipment for the SAAF's electronic intelligence configured Boeing 707.

A steerable electronic support measures (ESM) antenna is located beneath the rear fuselage on a mechanically retractable mount. The rear of the cabin houses a twin operator console supporting separate ESM and techniques roles.

The COMINT Oryx features a Grintek-developed fold-away dipolar antenna array projecting from the starboard side of the aircraft with a palletised signals processing and analysis suite fitted into the cabin. The system has a single operator.

The same firm was involved in the conversion of two SAAF Boeing 707s for COMINT operations in the early 1990s. One of these was also displayed for the first time at the show.

The Oryx jammer is primarily designed to support strike operations against enemy air defence sites by SAAF Denel Cheetah fighters. An initial version was probably in operational service during the final twelve months of operations against Angola in 1989.

The proposed upgrade programme will see the introduction of digital RF memory based signals processing and to provide improved performance against low probability of intercept radar emitters. The upgrade will also introduce a co-processing capability to handle more sophisticated signals environments.

The SAAF has only one Oryx fitted with the jammer suite, but the upgrade may see additional aircraft converted. According to the chief of the SAAF, Lt Gen Roelf Beukes: "We are looking at a certain number for specialised roles only and that programme is well on its way."

The 707 COMINT aircraft displayed featured a palletised Grintek signals processing suite with four multifunction operator consoles and a twin display command console.

Source: Flight International