Investigation Summary
The accident occurred during a period of high holiday traffic two days before Christmas. The crew was performing a night approach to Runway 20 at Palermo, a route that requires flying over the sea. Investigators determined that the pilots suffered from a form of visual illusion; they believed they were much closer to the runway than they actually were due to the bright airport lights visible in the distance. This led them to abandon their instrument-monitored descent and transition to visual flight too early. For the final nine seconds of the flight, the DC-9 maintained a dangerously low altitude of 150 feet at 150 knots. Without a visible horizon or ground lighting beneath them (the 'black hole' effect), the crew failed to realize they were descending into the water until the right wing impacted the surface.
Final Conclusions
The primary cause was the flight crew's decision to continue a visual approach at night without adequate distance monitoring, leading to a premature descent. Contributing factors included the lack of a radar service at Palermo at the time and the absence of a Ground Proximity Warning System (GPWS) on the aircraft, which might have alerted the crew to their proximity to the water.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
Altimeter
The crew failed to properly monitor the barometric altimeter during the final visual segment of the flight.
Visual Approach
The transition from instrument to visual flight occurred too early, leading to a loss of situational awareness over the dark sea.
Interesting Facts
- 01The aircraft was named 'Isola di Stromboli'.
- 0221 people survived the impact and were rescued by local fishermen.
- 03The crash occurred approximately 3 kilometers (1.9 miles) north of the runway threshold.
- 04This was the second-deadliest accident in Alitalia's history at the time.
- 05The aircraft was flying at 150 knots (280 km/h) during its final level flight segment.
Safety Actions & Advisories
GPWS Mandates
The accident highlighted the critical need for Ground Proximity Warning Systems (GPWS) to prevent CFIT accidents during night approaches over water.
Airport Radar Upgrades
Following the crash, improvements were made to air traffic control radar capabilities at regional Italian airports to better monitor approaching aircraft.