If the headwinds are a little strong or the OAT is high, the JNB to ATL leg on the 777 can be problematic.
One night we left with 40 empty seats and the same amount of revenue passengers behind.
On another, we pushed with a full airplane but not one bag or ounce of cargo in the holds.
On yet another, we departed with reduced fuel and had to flag stop in SJU where another crew had been pre-positioned to take the flight on to ATL.
Makes for a lot of happy campers.
Regardless, I still miss that plane.