Piper also introduced a new limitation: a zero-fuel weight of 4000 pounds, meaning that any weight over 4000 pounds had to be in fuel, not payload.
However, the zero-fuel weight stayed at 4000 pounds, so the benefit was a mixed blessing.
Airbus said the heavier version would include a 3t increase in maximum zero-fuel weight
as well as maximum landing weight, with a resulting 3t increase in payload.
This oversight led the crew to enter inaccurate centre-of-gravity and zero-fuel weight
data into the A330's computer systems, and delays in notification of the loading error meant the jet operated 10 more sectors before undergoing precautionary maintenance checks.
50 max zero-fuel weight
[tonnes] 61 max fuel canacity  24210 Tab.
The zero-fuel weight
is 9040 pounds, which, on the airplane we reviewed, allowed a hefty 2566 pounds in the cabin.
With a zero-fuel weight
of 6032 pounds, the 850 can carry 1334 pounds in the cabin and baggage areas.