Gungwa mountain
FOLLOWING A BREAK AT THORNHILL I returned to ops earlier than planned on 4 May. This was in response to a call from JOC Hurricane at Bindura. SB had received reports of a large ZANLA base just across the border in the vicinity of a high feature known as Gungwa mountain, upon whose summit was one of the border beacons. I was asked to pinpoint the base.
Flying a Cessna, I searched outwards from the mountain but failed to find any base. Only one place remotely resembled the type of temporary camp found inside Rhodesia. This lay in dense jesse bush at the base of Gungwa mountain itself. Because it was not possible to remain overhead for a detailed look, I had to fly all over the place before returning for a second and then a third look. I was not convinced that this was a base but I could not reject it either because too many cattle paths ran in parallel lines within and outside the jesse bush. If in fact it was the site of a CT base, I decided it was for no more than ten CTs residing on a temporary basis.
At Bindura I reported that there were no CT camps near Gungwa and that only the large patch of jesse bush offered the remotest possibility for a mere handful of CTs. I thought no more about the matter believing an OP (observation post) callsign would move in to monitor the site. However, a couple of days later I received instructions to fly to New Sarum and report to OC Flying Wing. On arrival, Wing Commander Bill Jelley told me that I was to fly lead Vampire on 6 May for the biggest air strike to date on the Gungwa mountain base. This was to be followed by every available helicopter making a vertical envelopment with RLI troops. I protested and made it quite clear that I felt that Air Force was being drawn into a huge ‘lemon’. My objections were noted, but SB interrogations of captured CTs had satisfied JOC Hurricane that the jesse bush lying at the base of Gungwa mountain fitted with the intelligence. The strike would go ahead as planned. It was then that I came to realise that the whole fiasco was going to be recorded on film. In fact I saw myself on national television giving the air briefing for the very air strike I had tried to prevent.
I flew in the lead Vampire piloted by Justin Varkevisser. We marked with a full load of 20mm cannon and two 50-gallon Frantans and were followed in rapid succession by two Vampires, six Hunters and three Canberras. Four Provosts came from behind the mountain just ahead of about twelve helicopters. The whole operation went like clockwork on a patch of bush that was devoid of any ZANLA presence.
As expected, I was used as the scapegoat for the wastage of air weapons. Because of this I refused, with Air HQ support, to be involved in a similar situation in late 1974.
Countering Strela missiles
AS I HAD PREDICTED, WE needed to lose aircraft to Strela missiles before the Treasury hurriedly provided funds for the research and modifications needed to protect helicopters and piston-driven aircraft. Flight Lieutenant Archie Ramsbottom was appointed the technical officer for the project. I became involved with him immediately on an ad hoc advisory basis and together we paid a visit to CSIR in Pretoria for discussions on Strela missiles and the steps to be taken to render them harmless.
A sensor that could ‘see’ objects radiating infrared energy in the 2-micron wave band controlled Strela flight. Highest intensity emissions were from the relatively small exposed sections of exhaust pipes and hot engine parts. However, the cumulative value of infrared radiating from an entire standard airframe, although apparently cold, presented a good target. Strela would initially home on the entire heat signature of an aircraft and only seek out the hottest spot late in its flight; hence the strikes on the exhausts of the two Trojans.
Exhausted gas plumes did not present any problem but it was quite obvious that hot exhaust stubs and any exposed sections of engines had to be shielded. This needed some clever design and engineering work, which our technicians managed quite easily. Surface paint was the bigger problem. We established that colour was not the main criteria in selecting a paint mix that exhibited low radiation properties in the 2-micron wave band. In fact, and surprisingly, it was easier to achieve this with white paint than in the camouflage colours we intended to retain.
Archie worked long hours with paint manufacturers and the Paint Shop at New Sarum to develop the ideal paint mixes for our camouflage colours. What they eventually produced virtually eliminated radiation of infrared energy in the critical wavelength sector, even when the surface was hot.
The dedication and enthusiasm of Air Force technicians and paint manufacturers made Archie’s job easier and the results were impressive. Provosts and Trojans looked the same as before except for strange-looking fibreglass fairings shaped like half cups that screened exhaust stubs that had been turned to face upwards. Simple screens were also used to disallow Strela from ‘seeing’ hot components through the cooling-gills under the engines.
Dakota exhausts required a different solution. This involved extending the exhaust pipes all the way to the trailing edge of the mainplanes where the pipes turned upwards to exhaust gases vertically. A wide tunnel-like fairing through which air flowed to keep the outer surface of the tunnel cool surrounded each long exhaust line. At the trailing edge of the mainplane, the tunnel fairing rounded upwards to screen the hot upturned outlet of the exhaust pipes.
Counter-Strela modifications for Alouettes and Cessna 185 aircraft were created by SAAF in conjunction with CSIR. The Cessna modifications were much the same as those developed for the Trojan. Alouette helicopters presented bigger problems because the entire engine and exhaust pipe were exposed. As with fixed-wing aircraft, it was necessary to modify the jet pipe to exhaust upwards and the entire engine was shrouded in a bath-like shield. This shield was without a top to allow access for engine servicing in the field. Because of this, the engine and jet pipe could be seen from the ground when a helicopter banked steeply.
All anti-Strela modifications were very successful and many Strela missiles were wasted against our slow aircraft.
Jets, however, could not be protected to the same degree. There was no easy fix to the exposed ends of jet pipes. All that could be done was to paint the airframes with the new paint to minimise total radiation, thereby limiting Strela’s ability to acquire target until a jet aircraft had passed its operator’s position.
When all the Strela protection work was completed, Archie and I paid a visit to Air Rhodesia’s top managers to suggest to them that their Viscount airliners should be protected along the lines of our Dakotas. The reason for our visit arose from tests we had conducted with a Strela missile that had been acquired by Air Force to evaluate our counter-missile work.
The missile’s firing mechanisms were neutralised and a battery pack replaced the regular pyrotechnic generator. As a mobile test bed, this modified missile worked very well. Our tests confirmed that our light aircraft and Dakota modifications were satisfactory, and that the missile could not easily ‘see’ Canberras and Hunters until after they passed abeam. During these tests we noted that, whereas a Viscount produced a stronger signature from its four exhausts than either a Hunter or a Canberra, its entire airframe and large under-wing exhaust pipes made the aircraft highly visible, irrespective of range and direction of travel.