This is according to a notice to airmen (NOTAM) issued on Monday 10 August, which was posted on aviation forum Avcom.
According to the notice, the Instrument Landing System (ILS) used at OR Tambo would be switched off by 16:00 as it was due for calibration.
“Instrument Landing System JS 03R/21L will be switched off today because it has reached its calibrations expiry date, 25 days extension, and 180 days exemption today,” the notice stated.
“Instrument Landing System JS 03L/21R also reaches its 90 days exemption period today; we have applied for the extra 90 days exemption, however the CAA has not yet signed; if not signed by 16:00 today (10 August) we will have to switch off these ILS’s as well,” it continued.
NOTAMs are filed with an aviation authority to alert aircraft pilots of possible hazards along their flight route or at a location that could affect the safety of the flight.
ILS employs ground-based antennae which provide pilots with their location relative to a particular landing strip.
This is particularly important during periods of bad weather, where clouds or mist may impede the pilots’ ability to view their approach to the airport.
As required by the International Civil Aviation Organisation (ICAO), a runway’s ILS needs to be calibrated regularly to ensure continued accuracy and safe use.
In South Africa, this responsibility lies with the South African Civil Aviation Authority (SACAA), which uses specially-equipped aircraft to perform the calibration.
More airports affected
According to another member of Avcom, OR Tambo is not the first South African airport to be affected.
Citing multiple previous NOTAMs, the member said that King Shaka, George, and Kruger airports have no ILS or VOR (another orientation system) due to calibration expiry.
The member added that Cape Town airport had been downgraded, likely due to calibration exemptions.
Solidarity Trade Union Deputy General Secretary Marius Croucamp also addressed the issue in a tweet on Tuesday morning.
The union represents numerous pilots in the industry.
A very serious situation has developed at OR Tambo International airport. The ILS instrument landing system is off due to the calibration that has expired. The CAA calibration aircraft that was written off in a crash has not yet been replaced. More SA airports affected.
— Marius Croucamp (@croucampm) August 11, 2020
Calibration aircraft crash
Croucamp’s tweet refers to one of the aircraft SACAA had previously used for calibration, which crashed after take-off from George airport.
The Cessna Citation II – carrying three SACAA crew members – was due to conduct calibration work for the airport’s navigation systems.
Captain Thabiso Tolo (49), first officer Tebogo Lekalakala (33) and Gugu Mguni (36), a flight inspector, died in the crash.
SACAA is still investigating the cause of the incident, an issue which has been met with scepticism from aviation experts, who don’t believe SACAA can investigate its own conduct in such a case.
SACAA’s financial woes
SACAA is facing a financial battle as it struggles with the impact of the COVID-19 pandemic on the aviation industry.
The initial lockdown regulations meant that the vast majority of domestic, regional, and international flights were grounded for several months.
SACAA draws its income from passenger safety fees, a fuel levy, and user-related charges, which include licensing, approval, and other regulatory service fees.
It previously warned Parliament that it would only be able to continue paying salaries until the end of the year or early 2021 should restrictions on flights remain for five to seven months.
MyBroadband contacted SACAA and the Airports Company of South Africa for a response to the NOTAMs and comments on the forum, but we did not receive feedback by the time of publication.