Two Delta Air Lines flights from South Africa to the US had to make stops for fuel on their way back to the US. The first diversion occurred on November 28th when Delta flight 201 from South Africa to Atlanta made a technical stop in Boston to be refueled.
A flight from South Africa to Atlanta was diverted to San Juan, Puerto Rico, where it continued on. New flight crews were required to fly the final legs to Atlanta.
Delta told Insider of the Boston diversion that the flight was changed because of the technical specifications of the A350 aircraft. This can happen on long-haul flights when optimal operating conditions are not met.
On an ultra-long-haul flight such as the one between South Africa and Atlanta, there are a lot of factors that can play a role. Since September 6, Delta has not seen a diversion on the route, and the route only reopened on August 1.
There could be a new demand for flights out of South Africa. The discovery of the Omicron coronaviruses variant and the start of travel restrictions imposed by the US government has prompted some travelers to leave South Africa for the US.
Henry Harteveldt, travel industry analyst and president of Atmosphere Research Group, told Insider that there are some unusual market conditions caused by the emergency of the Omicron variant and changes to travel policies in the US.
Delta wouldn't comment on how full its flights were.
The route may be seeing increased cargo demand as the weather gets warmer in South Africa and colder in the US, according to Harteveldt.
The city of Johannesburg is a "hot and heavy" place for airlines, meaning that aircraft are operating in high temperatures at a high elevation airport, which affects their performance capabilities. In the middle of the spring season in South Africa, November and December are when temperatures rise and aircraft performance suffers.
The start of the cold season in the Northern Hemisphere is in November and December. An ultra-long-haul flight such as the one between South Africa and Atlanta is at the top end of the A350-900 XWB's performance capabilities, and any adverse condition could affect its range.
The flight from Delta's hub in Atlanta took 17 hours and 16 minutes to make. The longest route in Delta's network was the Atlanta-Johannesburg route, which was retired in October 2020. The only aircraft in Delta's fleet capable of flying the route was the A350, which was used to relaunch the route in August.
If Delta hadn't used this aircraft on this route before, there might be a learning curve. I think they had some bad luck and the weather was bad enough for the plane to be diverted and refueled.
The experts agree that making fuel stops on flights can have a negative effect on Delta's reputation. Delta is the only other airline that flies non-stop between South Africa and the US.
One solution would be to restrict how many passengers and how much freight is carried on the plane. Before the flight becomes unprofitable, Delta will need to assess how much it can restrict.
If the A350 can't reliably perform the route without making stops and without significantly restricting its payload, then the airline has a fiduciary responsibility to reexamine whether that route should be operated.
