Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Confusion; Human-Machine Interface; Time Pressure; Workload
Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Flight Crew FLC complied w / Automation / Advisory; Flight Crew Overcame Equipment Problem; Flight Crew Took Evasive Action; Flight Crew FLC Overrode Automation
Aircraft; Human Factors; Procedure
After takeoff; the Captain - pilot flying - engaged the autopilot at 500 ft. and the aircraft immediately started to level off [and] then tried to descend. He disconnected the autopilot and returned the flight path to a climb. During that time we got a GPWS 'Don't sink' aural warning. Upon later investigation we figured out what had happened. The first point on the SID; GG511. has a speed restriction of 230 kt. which was loaded in the FMS. It was his intention to load 230/005A to command 230 kt./500ft. or above at GG511 but it was inadvertently loaded as 230/005 so the FMS wanted 230 kt. at 500 ft. at GG511; when the autopilot was engaged it tried to capture 500 ft. The rest of the departure and flight were uneventful. [The cause was] a mistake loading the FMS. [I suggest to] properly load the FMS and better cross-check from the pilot monitoring - myself.
Air carrier First Officer reported that a mistake during the FMS programming caused the aircraft to descend when the autopilot was engaged after takeoff.