Jimmy Hoffa Rocks
26th Jul 2016, 18:54
http://news.aviation-safety.net/2016/04/23/fatal-mali-md-83-accident-blamed-on-engine-icing-and-lack-of-stall-recovery/
Pilot error or insufficient training ( SEPLA) ?
The July 2014 accident involving an MD-83 in the Mali desert was caused by engine icing and the crew’s lack of appropriate repsonse to a stall, according to a report released by the investigation committee from Mali.
Causes (translated from French):
The speed of the aircraft, controlled by the auto-throttle, decreased due to clogging of the pressure sensors located on the nose cone of the engines, presumably by ice crystals. The autopilot then gradually increased the attitude of the aircraft to maintain altitude until the aircraft stalled. The stall of the aircraft was not recovered. The plane descended in a nose down attitude and a left bank while the rudders remain largely steered in the direction of a bank to the right. The plane hit the ground at high speed.
The accident resulted from the combination of the following:
– Non-activation of engine anti-icing systems;
– Clogging of pressure sensors Pt2, presumably by ice crystals, resulting in erroneous EPR values which caused the auto-throttle to limit the thrust delivered by the engines to a level lower than the thrust needed to maintain FL310;
– Late reaction from the crew at the decrease in speed and erroneous EPR values, possibly related to the crew workload associated with the avoidance of convective zone and communication difficulties with air traffic control;
– The lack of reaction from the crew to the appearance of the buffet, the stick shaker and the stall warning;
– The absence of appropriate action on the flight controls to exit a stall situation.
These events can find their explanations in the combination of the following factors:
– FCOM procedure for activating anti-icing systems was not adapted to the situation of blockage of Pt2 sensors by ice crystals;
– Insufficient information for operators on the consequences of blocking of the Pt2 sensor by an icing phenomenon;
– The trigger logic of the stick shaker and stall alarm that led these devices to trip late to the stall of the aircraft in cruise;
– The logic of the autopilot allowing it to continue to give orders to pitch beyond the impact of stall aggravating the situation leaving and increasing the difficulty of recovery by the crew.
¨This is the double reflection that makes the Spanish Union of Airline Pilots (SEPLA) the second anniversary since the crash of the Spanish airline Swiftair while on a flight for Air Algerie from Malian Ouagadougou to Algiers airport. The formation of ice crystals in a plane external probes sent wrong information to the autopilot of the aircraft and eventually led to his downfall, after a sequence of movements that the crew could not stop or reverse.
¨The union regrets that the industry did not act in time to prevent tragedies like this despite the record for identical reasons: "We do not learn from mistakes. The accident is a major flaw in the industry, we had all the background to not happen again. But the industry is slow and needs to be more efficient in implementing the recommendations. What they are issued if then not implemented. " Thus they reflected in a press release about the tragedy monographic Swiftair the head and deputy head of the technical department of SEPLA, Ariel Shocrón and Agustin Guzman, which was also attended by union president Javier Gomez Barrero.
But why interprets the SEPLA that is really a failure of the industry , understood as the sum of operators , manufacturers and operators ? First, by the background . Secondly, by the slowness , laziness or directly disregard of the recommendations issued after a plane crash to prevent its recurrence .¨
Pilot error or insufficient training ( SEPLA) ?
The July 2014 accident involving an MD-83 in the Mali desert was caused by engine icing and the crew’s lack of appropriate repsonse to a stall, according to a report released by the investigation committee from Mali.
Causes (translated from French):
The speed of the aircraft, controlled by the auto-throttle, decreased due to clogging of the pressure sensors located on the nose cone of the engines, presumably by ice crystals. The autopilot then gradually increased the attitude of the aircraft to maintain altitude until the aircraft stalled. The stall of the aircraft was not recovered. The plane descended in a nose down attitude and a left bank while the rudders remain largely steered in the direction of a bank to the right. The plane hit the ground at high speed.
The accident resulted from the combination of the following:
– Non-activation of engine anti-icing systems;
– Clogging of pressure sensors Pt2, presumably by ice crystals, resulting in erroneous EPR values which caused the auto-throttle to limit the thrust delivered by the engines to a level lower than the thrust needed to maintain FL310;
– Late reaction from the crew at the decrease in speed and erroneous EPR values, possibly related to the crew workload associated with the avoidance of convective zone and communication difficulties with air traffic control;
– The lack of reaction from the crew to the appearance of the buffet, the stick shaker and the stall warning;
– The absence of appropriate action on the flight controls to exit a stall situation.
These events can find their explanations in the combination of the following factors:
– FCOM procedure for activating anti-icing systems was not adapted to the situation of blockage of Pt2 sensors by ice crystals;
– Insufficient information for operators on the consequences of blocking of the Pt2 sensor by an icing phenomenon;
– The trigger logic of the stick shaker and stall alarm that led these devices to trip late to the stall of the aircraft in cruise;
– The logic of the autopilot allowing it to continue to give orders to pitch beyond the impact of stall aggravating the situation leaving and increasing the difficulty of recovery by the crew.
¨This is the double reflection that makes the Spanish Union of Airline Pilots (SEPLA) the second anniversary since the crash of the Spanish airline Swiftair while on a flight for Air Algerie from Malian Ouagadougou to Algiers airport. The formation of ice crystals in a plane external probes sent wrong information to the autopilot of the aircraft and eventually led to his downfall, after a sequence of movements that the crew could not stop or reverse.
¨The union regrets that the industry did not act in time to prevent tragedies like this despite the record for identical reasons: "We do not learn from mistakes. The accident is a major flaw in the industry, we had all the background to not happen again. But the industry is slow and needs to be more efficient in implementing the recommendations. What they are issued if then not implemented. " Thus they reflected in a press release about the tragedy monographic Swiftair the head and deputy head of the technical department of SEPLA, Ariel Shocrón and Agustin Guzman, which was also attended by union president Javier Gomez Barrero.
But why interprets the SEPLA that is really a failure of the industry , understood as the sum of operators , manufacturers and operators ? First, by the background . Secondly, by the slowness , laziness or directly disregard of the recommendations issued after a plane crash to prevent its recurrence .¨