What happened
On 22 August 2006, a Beech 65-A90 King Air, registration N712DB, was conducting a private flight from Weston to Ireland West Airport Knock. The flight's objective was to practice instrument approach procedures using a newly installed Garmin GNS 530 navigation system. During the flight, the weather conditions deteriorated, leading the crew to operate in Instrument Meteorological Conditions (IMC) under a Visual Flight Rules (VFR) flight plan.
While executing a go-around procedure at approximately 1,800 ft, the pilot-flying initiated a turn that resulted in an accelerating roll. The aircraft's bank angle exceeded 90°, eventually leaving the aircraft in an inverted position. The pilot-non-flying, who took control of the aircraft, attempted to recover. During this recovery, the aircraft was subjected to a high power setting and a nose-down attitude, causing a rapid increase in airspeed and significant G-loading. The aircraft eventually leveled off at 3,500 ft and returned to Weston, where it landed safely with no injuries to the two crew members.
The investigation
The investigation was initiated after an inspector discovered structural damage to the aircraft over a month after the event. Investigators examined the aircraft' and found buckling on the upper wing surfaces of both the port and starboard wings, as well as distortion in the tailplane. The manufacturer's assessment indicated that the damage was consistent with exceeding the aircraft's design limitations, specifically involving an over-speed condition and G-loads reaching at least 4.5 G.
Investigators also reviewed the pilots' credentials and the flight's operational context. It was determined that the pilot-flying's FAA license was invalid because his medical certificate was not recognized by the FAA. Furthermore, the investigation noted that the crew had not reported the accident immediately, which prevented the use of ATC radar recordings and was complicated by the fact that the onboard GPS lacked a track memory feature to reconstruct the flight path.
Findings
- The primary cause of the accident was the loss of control by the pilot-flying during the go-around procedure.
- The pilot-flying's lack of experience and loss of situational awareness contributed to the unintended roll.
- The pilot-non-flying failed to provide adequate monitoring of the flying pilot.
- The structural damage was a direct result of the recovery maneuver, which substantially exceeded the aircraft's flight manual limitations for speed and G-loading.
- The aircraft was being operated in IMC while under a VFR flight plan.
- The failure to report the accident promptly hindered the investigation's ability to access radar data.