My brother worked out the landing gear articulation, with mechanical locking; previous Boeings had complicated hydraulic valving to make the gear stop moving at the bottom, with the failure mode that it immediately folds back in.
Here's hoping some of the 777s are chosen for hydrogen-fuel conversion. A 2-4 year job for a dozen A/Ps, by my guess. Aerogel-insulated LH2 tank amidships, all new fuel piping, new or reconfigured engines, for tens of tons more payload, and ultimately all wind- and solar-powered.