Originally Posted by
Rejuvenated
I believe one the reasons why JNB gets the 744s during their summer the most has something to do with the nature of the elevation combined together with the summer weather there that makes it a compulsory 744 route. Perhaps someone with better understanding on the technical details of this issue can elaborate further.
The problem that CX used to have with a 343/744 long-haul fleet was a lack of efficiency with the 343 during the summer months. JNB is what is known as "hot and high" - a 5000+ ft elevation combined with the climate requires aircraft to either load up more fuel and/or restrict payload to get climb velocity. From the original CX press release announcing 744 services:
"Johannesburg is a high-altitude airport. Climactic conditions during the hot summer in the Southern Hemisphere favour the operation of the larger and more powerful B747-400, which Cathay Pacific plans to deploy with the commencement of the additional flight. During the cooler winter months the airline's Airbus A340-300 is a more cost-effective option."
Anecdotally I understand JNB is often full down the back, though of course that is no indication of yields and overall profitability.