What happened
The flight, which included a captain performing check airman duties and a first officer in training, proceeded normally through the takeoff, climb, and cruise phases. During the approach to Jacksonville Naval Air Station, the crew discussed changing runways twice due to heavy precipitation in the area. They eventually opted for a GPS approach to runway 10, which featured a displaced threshold and an ungrooved surface.
As the Boeing 737 (implied aircraft type from context of thrust reverser/flaps) descended, the crew configured the aircraft with landing gear and 30-degree flaps. However, the crew failed to place the speedbrake handle in the armed position as required by the landing checklist. While the initial descent was near the glidepath, the airspeed increased to 170 knots, which was 17 knots above the target speed, aided by a tailwind. The aircraft also drifted significantly above the 3-degree glidepath.
Shortly before touchdown, ground proximity warnings alerted the crew to a high sink rate. The aircraft crossed the displaced threshold 120 feet above the runway, maintaining a high descent rate and excessive speed. The aircraft touched down approximately 1,580 feet beyond the displaced threshold, exceeding the operator's standard touchdown zone. After landing, the pilot applied braking and deployed the No. 2 engine thrust reverser, but reported a lack of deceleration. The speedbrakes did not deploy until four seconds after touchdown, likely due to the failure to arm them prior to landing. The aircraft exited the runway 55 feet right of the centerline and struck a seawall before coming to rest in the St. Johns River. There were 0 fatalities reported in the provided text.
Findings
- The flight crew did not arm the speedbrakes before landing, which delayed their automatic deployment by approximately three seconds.
- The aircraft approached the runway at an airspeed 17 knots above the target speed.
- The aircraft's descent path was significantly higher than the prescribed 3-degree glidepath.