Our arrival at Cape Town today was not quite in the style that we intended. We left Walvis Bay on time and quickly climbed through a thin layer of SC which had crept in from the coast overnight to strong sunshine above. We followed the coast down with endless miles of sand to the left and sea to the right.
All was going well until about 300 nm from Cape Town, the red ‘low voltage’ light appeared and it was apparent that the main alternator had failed. We switched on the reserve generator which powered the turn and slip indicator, COM1/NAV1/GPSS1 and transponder no 2 and not much else. We advised ATC of the problem and continued towards Cape Town. Phil and I shared the flying as there was now no autopilot.
We were transferred to Approach who gave us vectors for a visual approach; we had kept our speed up to facilitate spacing for CAT and then at two mile final slowed down and I switched the main battery switch on to drop flap and undercarriage. This resulted in a total electrical failure so we broke off the approach and orbited left. Phil took over the flying while I hand cranked the undercarriage down and retrieved the hand held radio, and so we landed and taxied to our parking position. Two fire engines followed us down the runway – a first for us both!
I phoned Stellair at Stellenbosch (who are going to carry out a 50 hour check) and advised them of the problem and they put me in touch with an electrical engineer at Cape Town airport who came over and diagnosed a faulty alternator rather than in the wiring to/from the alternator. Eventually with the help of a GPU, we restarted Juliet Bravo and taxied her over to the engineer’s hangar. The engineer seems confident that it should be possible to sort the problem tomorrow but time will tell.
We had a car coming to collect us from Stellenbosch Airfield but this was diverted to collect us from the engineer’s hangar at Cape Town.
So all in all an interesting experience. On reflection, I should have switched the standby generator off before putting the battery master switch on to lower gear/flaps etc and I think this is what caused the electrical failure on short finals. Having two pilots aboard definitely helped in resolving the problems and Phil and I thought we handled the CRM aspects rather well. If this problem had to happen, then Cape Town is about the best place it could happen.
Walvis Bay to Cape Town: 723 nm in 5 hr including left hand orbits at Cape Town