What happened
On 21 October 2004, a McDonnell Douglas DC-9-83, registration HB-INV, operated by Helvetic Airways, was conducting a charter flight from Zurich to Pristina. While attempting a visual approach to runway 35, the crew encountered challenging meteorological conditions. To avoid patches of cloud, the aircraft drifted left of the runway centerline. The crew attempted to correct their position by executing a series of turns with significant bank angles at low altitude. During the maneuver, the crew initiated a go-around between 80 and 40 feet above the ground. Due to the late initiation of the go-around and the unstable state of the aircraft, the left wingtip made contact with the runway surface, resulting in structural damage to the wing. There were no injuries to the 165 passengers or the crew.
The investigation
The Swiss Aircraft Accident Investigation Bureau (AAIB) examined the flight data, cockpit voice recorder, and meteorological reports. The investigation focused on the flight path reconstruction, the crew's decision-making regarding the visual approach, and the coordination between the flight crew and Pristina approach control. Investigators also reviewed the aircraft's maintenance history and the operational procedures regarding visual approaches under low-visibility conditions.
Findings
- The approach to runway 35 was conducted under insufficient meteorological conditions.
- The flight crew utilized an inappropriate flying tactic, which led to suboptimal crew coordination.
- The aircraft performed flight maneuvers with considerable bank angles while in close proximity to the ground.
- The crew failed to maintain a stabilized approach, attempting to correct the flight path via aggressive maneuvering at very low altitude.
Safety action
Following the investigation, the following safety recommendations were noted:
- The Federal Office for Civil Aviation was advised to arrange for Swiss aviation companies and airports to implement higher minimum visibility (5 km) and ceiling (1000 ft) requirements for visual approaches.
- A recommendation was made to ensure that pilots holding Swiss instrument ratings possess the necessary fundamental knowledge regarding current instrument flight procedures and PANS-Ops.