If all engines quit in flight, control is maintained on Boeing jet transport aircraft in the following manner:
707/720 - Elevators and ailerons are manually operated via tabs, same as when all engines were working.
727/737 (All models) - Elevators and ailerons have tabs for manual reversion.
747 - Windmilling engines power all four hydraulic systems for all control surfaces, but at reduced rate.
757/767 - Ram Air Turbine (RAT) located in wing body fairing deploys and drives Center hydraulic system. Windmilling engines can provide some pressure to the Left and Right hyd. systems but landing flare capability does not depend on it.
777 - Same as 757/767 except RAT includes an electrical generator to keep the fly-by-wire flight control system operating.