Management, technical and engineering staff of OR Tambo International Airport have completed an assessment of the circumstances that led to power disruptions at the airport on Sunday 12 January.
OR Tambo GM Bongiwe Pityi-Vokwana released a statement that reads:
As a National Key Point, the airport is licensed and regulated by the South African Civil Aviation Authority (SACAA). We adhere to global standards for critical infrastructure systems back-up to ensure the safety and security of passengers going through our airport.
We have 45 generators which can operate for three days. We also have a large number of uninterruptable power supply (UPS) units that keep engineering and IT systems running when power is disrupted, giving generators the time required to start up.
In spite of the power interruption, the airport ecosystem handled 571 flights with more than 71 000 passengers and 39 000 departing bags processed. Twenty flights and 530 bags were affected by the power interruption, with delays averaged at 30 minutes for the flights concerned.
The sequence of events
A total loss of power from Eskom was reported at 10.24am. Our business continuity plans were activated. Back-up generators took over and various engineering and IT systems were reset at this point, the equivalent of rebooting.
Critical services such as fuelling, baggage handling, water supply, instrument landing system and aircraft navigational aids were not affected. The airside network comprising of airfield ground lighting systems, supplied by separate UPS systems and generators, was not affected.
The process of restoring Eskom loads ran from 12.40pm to 13.05pm. The transition from generator to mains and back is not seamless as loads are restored in phases. Some systems require 30 minutes and more before they are again fully operational.
Impact on systems
Back-up generators supplied uninterrupted power to the following areas:
* Domestic terminal and critical systems necessary for passenger processing;
* Airport fuelling system;
* Airfield navigational aids;
* Instrument landing system and aircraft navigational aids;
* Weather observation systems;
* Airfield ground lighting systems;
* Some people movers for vertical circulation and parking management systems; and
* Emergency lighting.
The following systems were partially affected during the interruption:
* Vehicle parking systems;
* People movers not on essential supply;
* Non-emergency terminal lighting;
* Retail outlets such as banks, restaurants and shops;
* IT systems and some related wire centres;
* International baggage handling system; and
* Public address system.
Every realtime disruption reveals some fresh challenges that cannot be anticipated in business continuity plans. Therefore, as part of adapting our responses, the airport will now do three things.
First, run more simulations of longer power outages to understand the impact on infrastructure; second, re-assess all systems and areas that are regarded as essential services with a view to providing additional capacity from back-up generator supply; and third, re-evaluate the synchronisation and sequencing of generators to mains power during supply restoration.
Management of OR Tambo International Airport understands the frustrations of people at times such as this and we thank passengers and airport visitors for their understanding.
We are also most appreciative of the support provided by everyone working in the airport environment. Their efforts helped to mitigate the effects of the disruption and enabled the efficient return to normal operations once power had been restored.