B737 Undifferentiated or Other Model
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Workload; Distraction; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Excursion Runway; Inflight Event / Encounter Unstabilized Approach
General None Reported / Taken
Human Factors; Weather
Planned for 22L arrival. On initial contact with arrival 22R was assigned.On short final GPWS constant 'below glide slope' call-outs. PAPI was all red. Noticing red side lights and PAPI location; I stated 'displaced-threshold'; Captain responded something like 'yes or got-it'. He reacted as if to land beyond. Power/Pitch. Landed close to displaced threshold; unsure if beyond or not.Change of planned runway. Lack of attention to airport diagram.
Planned on 22L ILS; cleared 22R ILS. Transitioned to visual when well clear of weather because of offset localizer; used 3 degree line on HUD; intended to land beyond displaced threshold and I think we did but not 100 percent sure.
B737 flight crew reported possibly landing before the displaced threshold by mistake.