Aircraft Crash on La Rodilla de la Mujer Muerta (EC-ANR)

Flight Details and Timeline The aircraft departed from Vigo airport at 1540 hours on a scheduled flight to Madrid. The flight carried a crew of 5 and 16 passengers. It was cleared for Instrument Flight Rules (IFR) at cruising level 95. At 1605, the flight reported to Madrid D. F. station that it had overflown Guinzo de Lirnia at 1600 in cloud conditions and estimated reaching the Salamanca JW radio beacon at 1650. At 1654, the aircraft advised Madrid D. F. station that it had overflown Salamanca at 1650 at level 95 and estimated arriving in Madrid at 1730. The crew also reported that its VHF equipment was out of order and requested Barajas Tower to stand by on 3023.5 kc/s. At 1710, Madrid control cleared the aircraft to proceed directly to the Barajas radio range while maintaining flight level 95. At 1715, Madrid control authorized the aircraft to switch to 3023.5 kc/s and establish contact with Barajas Tower. This was the last communication with the aircraft. Between 1715 and 1720, the aircraft crashed and burst into flames on the peak of La Rodilla de la Mujer Muerta, which is 1,999 metres high, approximately 800m lower than flight level 95. All aboard were killed and the aircraft was destroyed. ## Probable Cause The official findings concluded that if the accident was due to meteorological factors, icing would have been the factor most directly responsible. It is assumed that during its flight through innocuous stratiform clouds, the aircraft may have encountered a cumulus congestus where sudden severe icing occurred. A sudden change in the aerodynamic characteristics of the aircraft may have caused stalling without giving the captain time to initiate recovery action. Alternatively, the aircraft may have lost height rapidly, down to a level where the downdrafts over the lee slope swept it into a lower zone of erratic turbulence that sent it out of control. When icing occurred, the captain may, in the belief he had already passed the mountain divide, have decided to fly below the freezing level, which was known to be at about 2,200 metres. Turbulence within the cumuli may have been a contributing factor. Under severe icing conditions, the mechanical de-icing equipment is practically inoperative. About 40 minutes before the accident, the mountain divide was overflown at level 95 by a scheduled Santiago-Madrid flight, which found nothing unusual to report, as light icing and turbulence are normal in winter weather in a low pressure area. This fact, however, does not preclude the possibility that severe icing conditions may have prevailed shortly thereafter.