Scheduled passenger services between South Africa and its northern neighbour, Zimbabwe, were disrupted this past weekend after either country's civil aviation authority sanctioned commercial aircraft registered in the other's jurisdiction.

The stand-off began on Friday, August 18, when the South African Civil Aviation Authority (SACAA) grounded Air Zimbabwe (UM, Harare International) B767-200(ER) Z-WPE (msn 24713) at Johannesburg O.R. Tambo just prior to its departure for Harare International as UM462.

SACAA said in a statement a pre-flight ramp inspection revealed the aircraft did not comply with its regulations and safety requirements thus necessitating its grounding.

“The ramp inspection conducted by the SACAA personnel discovered that this operator was not compliant with both international civil aviation standards, and Part 129 of the South African civil aviation regulations,” a SACAA statement said. “Part 129, among others, requires an operator to be in possession of a Foreign Operator’s Permit in order to conduct operations into, and within South Africa. A copy of the Foreign Operator’s Permit, together with other documents, must be onboard an aircraft at all times, and made available for inspection on request by the relevant authorities."

In an apparently retaliatory move, the Civil Aviation Authority of Zimbabwe (CAAZ) grounded a South African Airways (SA, Johannesburg O.R. Tambo) B737-800, ZS-SJM (msn 30476), at Harare International just prior to the departure of its return service - SA25 - to Johannesburg O.R. Tambo on Saturday, August 19, citing the same reasons - a lack of a Foreign Operators Permit (FOP).

"SAA was notified of the decision on Saturday morning and flight SA025 from Harare to Johannesburg could not operate at 07h00," the carrier said in a statement. "SA022, which was scheduled to depart at 10h45 from Johannesburg to Harare, has also been cancelled."

Zimbabwean media reports state the embargo also affected Comair (South Africa), which operates as a British Airways franchise.

Zimbabwean Minister of Transport, Jorum Gumbo, subsequently engaged his counterpart in South Africa, Joe Maswanganyi, to resolve the impasse which ended on Sunday, August 20.

Flightradar24 ADS-B data shows Z-WPE returned to Harare on the evening of August 19 in time to conduct its Sunday milkrun between Harare and Johannesburg as UM467/8. For its part, ZS-SJM returned to service on Sunday as SA25 Harare-Johannesburg.

"Since the grounding of SAA’s aircraft in Harare yesterday, the airline prepared and submitted all required documentation in compliance with the instruction from the Zimbabwean authorities," a follow-up SAA statement issued on Sunday, August 20, said. "Following the clearance and approval received, SAA started recovering its schedule."