What happened
Following its delivery on 17 October to TAB1 at Wagner Field, Florida, the Lockheed C-130 underwent several days of performance testing. These evaluations focused on the aircraft's double-slotted flaps system and its ability to maintain a steep eight-degree glide slope at low speeds. On 29 October, a scheduled full profile test was conducted. While the takeoff portion of the flight successfully established new short takeoff records, issues arose during the landing sequence.
The testing involved the use of eight ASROC rockets mounted on the fuselage to assist with deceleration. Due to a need for further calibration of the automated firing computer, the crew opted to manage the rocket commands manually. The configuration included upper pairs located behind the cockpit and lower pairs situated along the mid-fuselage. While the upper rockets could be ignited while airborne, the lower rockets were intended to fire only after ground contact.
During the landing phase, the flight engineer mistakenly believed the aircraft had already touched down due to the visual obstruction caused by the upper rocket ignition. This led to the premature activation of the lower rocket set. Simultaneously, the descent-braking rockets failed to deploy. The sudden application of the lower rockets caused the aircraft's forward velocity to drop almost instantly, resulting in a heavy impact with the runway. The force of the landing caused the starboard wing to break between the third and fourth engines. A fire ignited on the trailing wing during the rollout, but it was quickly suppressed by crash response teams and a medical evacuation helicopter.
Findings
The primary cause of the accident was the premature manual activation of the lower deceleration rockets by the flight engineer, who believed the aircraft was already on the runway. Some unofficial reports from the crew suggested that an electrical or computer malfunction may have also caused the lower rockets to fire independently while preventing the descent-braking rockets from functioning. Following the incident, the aircraft, registration 74-1683, was dismantled and buried at the site for security purposes, though many specialized components were recovered.