A 2020 study fitted Andean condors with instruments recording every wingbeat across whole flights. Across more than 200 hours of flying, flapping accounted for about one per cent of flight time, and most of that was concentrated in take-off.
The reason is size. Adults weigh up to fifteen kilograms with wingspans approaching three metres, so powered flight is expensive and continuous flapping is not viable. Condors instead extract energy from the atmosphere, climbing in thermals over sun-warmed slopes and using orographic lift where wind is deflected upward by ridges. Take-off from flat ground is the hard part, which is why they favour cliff ledges and exposed perches.
The largest wingspan claims for the species are unreliable; measured birds cluster around 2.7 to 3.2 metres, and larger figures usually come from stretched museum specimens or unverified reports.