- Two Delta Air Lines flights from South Africa had to make fuel stops last week.
- A mixture of deteriorating weather conditions for airplanes and an increase in the number of passengers and / or cargo could be to blame, experts say.
- Both flights, operating from Johannesburg to Atlanta, were operated by Airbus A350-900 XWB aircraft.
Two Delta Air Lines flights between South Africa and the United States have had to make unscheduled stops for fuel in recent days on their way back to the United States. The first diversion occurred on November 28 when Delta Flight 201 from Johannesburg, South Africa, to Atlanta made a technical stop in Boston for refueling.
Another flight from Johannesburg to Atlanta that took off on December 2 was diverted to San Juan, Puerto Rico, where it also refueled before continuing. Delta said the two stopovers were “pre-planned” and new flight crews were to complete the final stages to Atlanta.
“The flight redirection was tied to the technical specifications of our A350 aircraft and the payload of that particular flight,” Delta told Insider of the Boston hijacking, in a statement. “This can happen on ultra-long haul flights when optimal operating conditions cannot be met.”
There are many factors that can play a role in a diversion, including weather conditions and payload, especially on an ultra-long-haul flight such as Johannesburg to Atlanta. Delta has not seen a detour on the route since September 6, the earliest date available for display using FlightAware tracking data, and the route was not relaunched until August 1.
One possibility could be a new demand for flights from South Africa leading to more fully booked flights. The discovery of the Omicron variant of the coronavirus and the start of travel restrictions imposed by the United States government have prompted some travelers to leave South Africa for the United States.
“You have unusual market conditions posed by the urgency of the Omicron variant and the changes in travel policies in the United States,” Henry Harteveldt, travel industry analyst and president of Atmosphere told Insider. Research Group.
Delta declined to comment on the occupancy rate of its flights on both occasions. But fuller flights are just one possibility among many that could affect an ultra-long-haul route such as Atlanta-Johannesburg.
The route could see an increase in freight demand, Harteveldt said, and the weather could also play a role as the weather warms in South Africa and colder in the United States.
Johannesburg is a “hot and heavy” city for airlines, which means planes operate at high temperatures in an airport at high altitude, which affects an aircraft’s performance capabilities. November and December are the middle of the spring season in South Africa, when temperatures rise and aircraft performance suffers.
And in the northern hemisphere, November and December mark the start of the cold season and when the winds get stronger. An ultra-long-haul flight such as Johannesburg to Atlanta is already at the peak of the performance capabilities of the Airbus A350-900 XWB, and any adverse conditions could affect its range.
Delta Flight 201 on Nov. 29 was able to complete the 7,300 nautical mile nonstop trip in 17 hours and 16 minutes, according to data from FlightAware. Delta previously flew the Boeing 777-200 on the Atlanta-Johannesburg route, the longest route in Delta’s network, until the aircraft was retired in October 2020. As the only aircraft in Delta’s fleet capable of traveling the route, the A350 was used to relaunch the route in August and Delta is still accommodating use of the aircraft on very long-haul routes.
“There might be a little learning curve here for Delta if they haven’t used this aircraft on this route before,” Bruce McClellan, aviation analyst at Teal Group told Insider. “I just think, probably, that they had some bad luck and had some pretty bad weather that caused the plane to divert and refuel.”
Both experts agree that fuel stopovers on scheduled non-stop flights can have reputational issues for Delta if they continue. United is currently Delta’s main competitor as the only other airline to operate non-stop flights between South Africa and the United States.
One solution could be to restrict the number of passengers and the amount of cargo carried on the plane even more than today. Delta will then need to assess how much it can restrict before the flight becomes unprofitable.
While the A350 cannot perform the route reliably without making stops and severely restricting its payload, Harteveldt said, “the airline has a
responsibility to reassess whether this route should be operated. “