A Cessna 500 Citation I corporate jet operated by City-jet was destroyed when it struck the side of a mountain near Cagliari on the Italian island of Sardinia. The airplane was on approach to Cagliari-Elmas Airport (CAG) following a domestic flight from Roma-Ciampino Airport (CIA). On the evening of 23 February 2004, the Austrian air taxi operator City-jet was requested to carry out a flight from Cagliari-Elmas Airport (CAG), Sardinia, Italy to Roma-Ciampino Airport (CIA) and return. The purpose of the flight was to transport a team of three doctors to Rome who would need to remove a organ for transplantation. The crew would wait at the airport to return to Cagliari with the medical staff and the organ. CIT Flight 123 took off from Milan Linate at 22:22 and landed at Cagliari without incident at 00:02, February 24. After refueling (1100 liters) and the three passengers had boarded, the aircraft departed at 01:01 bound for Rome, where it landed at 01:51. After arriving at Ciampino Airport, the crew filed an IFR flight plan for Cagliari, alternate Olbia, call sign CIT 124, with Estimated Off-Block Time (EOBT) 04:00. The flight was declared STS/HOSP (medical flight). After arrival of the medical team, takeoff occurred at 05:00. The aircraft was authorized by Rome ACC to directly enter the airway M126, without carrying out the standard instrument departure. The en route part of the flight to Cagliari was uneventful. At 05.37, Rome ACC instructed flight 124 to contact Cagliari APP, After radio contact was established , Cagliari APP provided the weather at the aerodrome: runway in use 32, wind 7 knots from 320ø, visibility 12 km scattered clouds at 2000 feet, temperature 10ø C, dew point 9ø C, QNH 1012. At 05.41.12, Cagliari APP instructed CIT 124, which at that time was at the waypoint Aledo, to continue the descent over the next waypoint LEDRO up to 5000 feet, to carry out the ILS procedure for a landing on runway 32 and report at Carbonara VOR. The commander, reading back the instructions, requested permission to conduct a visual approach should he obtain visual contact with the airport: “Roger, we are cleared now to descend to five thousand feet on the QNH one zero one two and we passing Ledro cleared by ILS three two papa and if we have field visually, we would like to have a visual approach.” This was confirmed by Cagliari APP. At 05:43 the flight crew radioed: “CIT 124, we have the field in sight requesting visual approach.” At that time the aircraft was at FL 96, about 28 nm from Carbonara VOR and about 41 nm from Cagliari VOR. Cagliari APP then asked CIT 124 about the ability to maintain obstacle clearance: “confirm able to maintain your own separation from the obstacles sir, performing visual approach runway three two”. The pilot just replied: “affirmative, CIT 124”. About three minutes later, Cagliari APP informed CIT 124 to continue the descent without descending below 2500 feet and contact Elmas TWR for the further descent: “[…] CIT 124 continue not below 2500 feet, further descent with Elmas Tower 120.6 bye” The pilot contacted Elmas TWR at 05:47: “Elmas Tower, buongiorno, CIT 124, visual, left procedure, for visual approach runway 32.” Elmas TWR responded by reporting the runway in use (32), wind conditions (8 knots from 310ø), and told the flight to report on short final for runway 32. This was read back by the crew. Two minutes later, while descending over mountainous terrain, flight 124 collided with the side of Su Baccu Malu Mountain (3333 feet). CAUSA E FATTORI CONTRIBUTIVI L’incidente, classificabile come CFIT, Š stato causato dalla conduzione del volo ad una quota significativamente inferiore all’altitudine minima di settore, insufficiente a mantenere la separazione dal terreno, durante un avvicinamento a vista notturno in assenza di adeguati riferimenti visivi. Sono stati individuati i seguenti possibili fattori contributivi dell’incidente: – strumentazione dell’aeromobile non comprendente uno strumento GPWS o TAWS, la cui installazione non Š richiesta dalla normativa; – l’assunzione da parte dell’equipaggio di riferimenti visivi erronei, confusi con le luci pista di Elmas, tenuto conto che l’equipaggio non aveva particolare familiarit… con la zona di Cagliari; l’insorgenza, nell’equipaggio, di fenomeni di illusione ottica, con specifico riferimento al cosiddetto “black hole approach”; – il fraintendimento, da parte dell’equipaggio, dell’istruzione data da Cagliari APP all’atto del trasferimento a Elmas TWR (“CIT 124 continue not below 2500 feet, further descent with Elmas TWR 120.6 bye”), che potrebbe aver ingenerato il convincimento, malgrado lo stesso equipaggio avesse confermato di essere in grado di separarsi autonomamente dagli ostacoli, che la discesa fino a quella quota fosse libera da ostacoli; – mancato utilizzo delle procedure strumentali pubblicate e disponibili nella conduzione di avvicinamento su di un aeroporto e in un’area non conosciuti, in condizioni di totale oscurit…; – l’anticipazione della deviazione dall’aerovia, forse decisa per cercare di accelerare l’arrivo a destinazione, che ha determinato il sorvolo di aree di maggiore elevazione; – errori di lettura delle quote riportate nelle carte consultate, facilitati dalla mancata rappresentazione a colori del terreno; – il prolungato periodo di veglia senza adeguato riposo, che potrebbe aver contribuito a ridurre la performance dell’equipaggio. translated from the original Italian text: CAUSE AND CONTRIBUTORY FACTORS The accident, classified as CFIT, was caused by the conduct of the flight at a height significantly below the Area Minimum Altitude, insufficient to maintain the separation from the ground during a night visual approach in the absence of adequate visual reference. possible contributory factors that have been identified: – The aircraft instrumentation did not include a GPWS or TAWS, whose installation is not required by law; – The erroneous descent by visual flight references, confusing the Elmas runway lights, given that the crew had no special familiarity with the area of Cagliari, the onset of a perspective illusions phenomena, with specific reference to the so-called “black hole approach”; – The misunderstanding by crew members, of the Cagliari Approach controllers instruction to transfer to Elmas TWR (“CIT 124 continue not below 2500 feet, further descent with Elmas TWR 120.6 bye “) which may have created the impression, despite the crew had confirmed that they are able to separate themselves from the obstacles that the descent down was free of obstructions; – Failure to use published procedures and available instruments in a descent to a closer airport and in an unfamiliar area , under conditions of total darkness; – The anticipation of the deviation from the airway perhaps caused [the crew] to try to speed up the arrival at destination, which determined overflying areas of higher elevation; – Read errors of the elevations listed in the maps consulted, facilitated by the non representation of the ground color; – The extended period of wakefulness without adequate rest, which may have contributed to a reduction in the performance of the crew.