With thanks to 1103 who posted these quotes on my forum:
From Brian Trubshaw's autobiography - Test Pilot - page 64
"It is worth recording that in 1972-73 BOAC reported that the Super VC10's were averaging 11.09 hours per day compared to the 707's 8.7 hours and the operating costs per revenue flying hour were £486 for the Super VC10 and £510 for the 707".
From Sir George Edwards biography - From Bouncing Bomb to Concorde - page 138
"The VC10 achieved load factors nearly 20% higher than the average of fourteen other airlines and were soon attracting average payloads of 70%, which according the Charles Gardner, made them a bigger profit earner than the optimum 707. these high numbers were sustained by BOAC as the aircraft became ever more popular, becoming the preferred choice for regular passengers despite extensive choice.
Gardner concluded; 'So the Super VC10, denigrated in advance by BOAC as too expensive to operate economically - and for which they obtained some £30 million in subsidy as recompense - turned out to be actually cheaper to fly than the 707 and also attract more passengers'."
From the book British Aircraft Corporation - A history by Charles Gardner
The breakdown of load factor figures were in 1965
Super VC10 ...........................................71.6%
Average BOAC........................................60.8%
Average for 14 airlines (excluding BOAC)........52.14%
BOAC's 707 figures were inflated by over-spill from fully booked Super VC10s.
And what is difficult to figure out are the total costs of the aircraft when maintenance is factored in. The 707s were apparently lifed to something like 30,000 hours and then needed a large bulk of cash to get back into service. The VC10s in comparison had a much less costly programme to extend its service life and this could be done more often.
More details here:
A Little VC10derness ? View topic - 707 higher overall cost of ownership than the VC-10 ?