The SADF objective was to halt a Soviet-backed counteroffensive by the People's Armed Forces of Liberation of Angola (FAPLA) on the contested settlement of Mavinga.

UNITA Liaison Team – Colonel Fred Oelshig Mobile Air Operations Team – Major Brian Daniel (SAAF 89 Combat Flying School)[citation needed] 20 Medical Task Force – Commandant John Lubbe 20 Artillery Regiment – Colonel Jean Lausberg Combat Group Bravo – Commandant Robbie Hartslief Reserve The South Africans began Operation Moduler on 13 August with Sierra Battery unleashing 120 mm mortar fire on the 47 and 59 Brigades halting their advance at Catato Woods.

[6] During this period the Ratel-90 anti-tank squadron was advancing north to Mavinga while between 26 and 28 August, SAAF C-130s flew in the eight G5 battery and their support equipment for deployment to the Lomba River region.

[9] Flying an artillery observation officer on the night of 3 September, a SAAF Bosbok light aircraft was intercepted and shot down by a SA-8 south of the Lomba River killing the two occupants.

[10] Combat Group Bravo sent its Ratel 90 anti-tank squadron forward with a company from 101 Battalion and they encountered a fording BTR-60 that they destroyed but FAPLA artillery counter-attack and it forced the South African units to withdraw 6 km away.

[10] The detached unit of Combat Group Bravo returned on 10 September to the fording site on the Lomba River and again attacked elements of 21 Brigade, but the Angolans' counter-attacked sending in three tanks.

[11] MiG aircraft then arrived over the battle site and forced the South African units to withdraw but they had stopped 21 Brigade's advance.

[11] Later that night, President PW Botha, Defence Minister Magnus Malan and the generals flew into Mavinga and met Deon Ferreira and his officers the following day for a briefing.

[11][17] President Botha decided on a more offensive operation and the release of any SADF forces required to destroy the remaining FAPLA brigades east of Cuito Cuanavale.

[19] The South Africans withdrew to resupply around 12h00 and resumed their attack from 14h00 with the Angolans now attempting to retreat across the river taking even more casualties but the battle was over by 17h00.

[20] The same day saw plans formulated for 32 Battalion to send units to attack and disrupt the FAPLA supply lines between Menongue and Cuito Cuanavale.

[18] Angolan MiGs patrolled the skies above the South African units on 11 October and launched sporadic attacks but no damage or casualties are recorded.

[22] The same day saw the SADF artillery in position south of the Mianei River and would begin to shell Cuito Cuanavale for several weeks and the airfield outside the town and would eventually abandon all flights of aircraft.

[23] 20 Brigade is renamed Task Force 10 on 23 September with Ferreira remaining in command of the newly named unit comprising Combat Groups Alpha and Charlie.

[24] After a ten-day journey from Rundu, 4 SAI under Commandant Leon Marais arrived outside Mavinga on 30 October with thirteen Olifant tanks and became part of Combat Group Charlie.

Combat Group Bravo, who was close by, was sent forward as was a 61 Mechanised Battle Team from Mavinga that consisted of a mechanized infantry company and a Ratel-90 platoon under Major Dawid Lotter and they found the enemy within 2 km of the stuck guns.

[28] In the days leading up to 9 November attack, the SAAF conducted sorties against 16 Brigade positions with Mirages and Buccaneers to keep the FAPLA unit in place.

[29] The 7 November saw the SADF Tactical HQ moved up from Mavinga to Combat Group Charlie's position that was 45 km east of 21 Brigade and the Task Force 10 commander and his officers finalised the plan and its coordination.

[31] November 8 saw the SADF units complete their last-minute repairs and replenishment while the Tactical HQ moved later that evening south and then to the west close to the positions of Combat Group Alpha.

[44] Charlie's attack resumed around 10h00 as it had again been held up by poor navigation through thick bush and MiG bombing runs taking one wounded and this allowed FAPLA to withdraw some of its units in the south.

After resting Charlie regained the momentum around 12h25 when six Mirages bomb 16 Brigade positions but are then counter-attacked by the enemy infantry and artillery but is eventually beaten back with the loss of 2 killed and eight wounded.

[46] Early morning of the same day, saw an accidental explosion of an artillery round in a G5 gun which killed 2 SADF gunners and badly wounded another eight.

[46] Radio intercepts around 14/15 November reported that 16 Brigade no longer existed as a cohesive unit as the soldiers had deserted to Cuito Cuanavale.

[52] The battle lasted until 16h30 with Combat Team Bravo joining Charlie after engaging further tanks before withdrawing twelve kilometres when they ran short of ammunition and fuel.

[52] Alpha stepped off at 08h30 but its progress was hindered by UNITA's faulty intelligence concerning a minefield which slowed it down to a halt while the ground ahead was inspected.

[56] Alpha was hindered as it approached its attack on 21 and 25 Brigades as the bush was extremely thick and the armoured vehicles were unable to move fast.

[58] The third option had been discussed by the generals on 2 November, but would require another brigade on the western side of the river that would have to be made up of Citizen Force units who could only be ready for operations by the earliest 20 December.

[61] The heights favoured a defence plan aided by thick vegetation and sand so FAPLA forces dug in with their morale raised with the arrival of 300 Cuban soldiers.

[63] Due to heavy bush and trees, the SADF armoured vehicles found it difficult to turn their turrets and the vegetation hindered proper navigation.

[66] At the conclusion of the final phase of Operation Moduler, FAPLA casualties were estimated at 525 killed with the loss of 28 tanks, 10 BTR-60s, 85 other vehicles and 3 SA-13 anti-aircraft missile systems while the SADF was said to have lost 16 soldiers with 41 wounded.