Incident Overview
Description
Sabena flight 503, a Douglas DC-6, hit Monte Terminillo in Italy, killing all 29 occupants. The Sabena DC-6 departed Brussels (BRU), Belgium at 17:17 on a scheduled flight to Rome-Ciampino (Italy), Kano (Nigeria) and Lopoldville (now Kinshasa, D.R.Congo). Contact with Ciampino ACC was initiated according to plan at 19:29 , at which time the aircraft had passed over Florence at 17500 feet. At 19:48 Ciampino control asked the aircraft whether it had passed over Viterbo. Instead of answering this question directly, the crew inquired whether the Viterbo NDB was on full power. The controller replied that another aircraft had overflown the Viterbo NDB shortly before and had found it to be operating properly. At 19:51 GMT the aircraft stated that it had passed over Viterbo NDB one minute previously and requested clearance to descend to 5500 feet ; this was granted . One minute later it inquired whether the Ciampino ILS were operating and received an affirmative reply. At 19:53, OO-SDB called Rome control but communication was suddenly cut off. The airplane hit the slope of the Costone dell’Acquasanta at a height of 1700 metres. PROBABLE CAUSE: “The navigation was conducted without making use of all such radio aids as would have permitted checking, and consequently correcting the drift of the aircraft whereas the crew actually remained unaware of the drift. In fact, instead of making sure they were over the Viterbo beacon, they merely held that conviction, and therefore the approach procedure to the Rome terminal area (which prescribes overflight of the Viterbo beacon) was erroneously applied. The following contributing causes may be taken into consideration, 1) crosswind to the route stronger than forecast; 2) weather conditions particularly unfavourable to radio reception in MF.”
Primary Cause
Navigation error ? failure to utilize all available radio aids to correct the aircraft’s drift.Navigation error ? failure to utilize all available radio aids to correct the aircraft’s drift.Share on:
