The Russian Federation’s Interstate Aviation Committee has released its final report into the crash of a flydubai Boeing 737-800 in 2016 that killed all 62 people on board.
The incident occurred on March 19 2016 on flydubai flight FZ 981, operated by 737-800 A6-FDN, from Dubai to Rostov on Don. There were 55 passengers and seven crew on the flight.
After an aborted approach to land on Rostov airport Runway 22 due to weather, the aircraft entered a holding pattern for about two hours before commencing another attempt to land.
The flight crew also aborted this landing and commenced a go-around. However, the aircraft crashed just off the runway and burst into flames. There were no survivors.
The Aviation Herald has published portions of the report that relate to the probable cause of the flydubai crash. It is reproduced here with minimal editing:
The fatal air accident to the Boeing 737-8KN A6-FDN aircraft occurred during the second go around, due to an incorrect aircraft configuration and crew piloting, the subsequent loss of pilot in command’s (PIC) situational awareness in nighttime in instrument meteorological conditions (IMC). This resulted in a loss of control of the aircraft and its impact with the ground. The accident is classified as Loss of Control In-Flight (LOC-I) occurrence.
Most probably, the contributing factors to the accident were:
– the presence of turbulence and gusty wind with the parameters, classified as a moderate-to-strong “windshear” that resulted in the need to perform two go-arounds;
– the lack of psychological readiness (not go-around minded) of the PIC to perform the second go-around as he had the dominant mindset on the landing performance exactly at the destination aerodrome, having formed out of the “emotional distress” after the first unsuccessful approach (despite the RWY had been in sight and the aircraft stabilized on the glide path, the PIC had been forced to initiate go-around due to the windshear warning activation), concern on the potential exceedance of the duty time to perform the return flight and the recommendation of the airline on the priority of landing at the destination aerodrome;
– the loss of the PIC’s leadership in the crew after the initiation of go-around and his “confusion” that led to the impossibility of the on-time transition of the flight mental mode from “approach with landing” into “go-around”;
– the absence of the instructions of the manoeuvre type specification at the go-around callout in the aircraft manufacturer documentation and the airline OM;
– the crew’s uncoordinated actions during the second go-around: on the low weight aircraft the crew was performing the standard go-around procedure (with the retraction of landing gear and flaps), but with the maximum available thrust, consistent with the Windshear Escape Manoeuvre procedure that led to the generation of the substantial excessive nose-up moment and significant (up to 50 lb/23 kg) “pushing” forces on the control column to counteract it;
– the failure of the PIC within a long time to create the pitch, required to perform the go-around and maintain the required climb profile while piloting aircraft unbalanced in forces;
– the PIC’s insufficient knowledge and skills on the stabilizer manual trim operation, which led to the long-time (for 12 sec) continuous stabilizer nose-down trim with the subsequent substantial imbalance of the aircraft and its upset encounter with the generation of the negative G, which the crew had not been prepared to. The potential impact of the somatogravic “pitch-up illusion” on the PIC might have contributed to the long keeping the stabilizer trim switches pressed;
– the psychological incapacitation of the PIC that resulted in his total spatial disorientation, did not allow him to respond to the correct prompts of the first officer (F/O);
– the absence of the criteria of the psychological incapacitation in the airline OM, which prevented the F/O from the in-time recognition of the situation and undertaking more decisive actions;
– the possible “operational” tiredness of the crew: by the time of the accident the crew had been proceeding the flight for six hours, of which two hours under intense workload that implied the need to make non-standard decisions; in this context the fatal accident occurred at the worst possible time in terms of the circadian rhythms, when the human performance is severely degraded and is at its lower level along with the increase of the risk of errors.
The lack of the objective information on the head up display (HUD) operation (there were no flight tests of the unit carried out into the entire range of the operational G, including the negative ones; the impossibility to reproduce the real HUD readings in the progress of the accident flight, that is the image the pilot was watching with the consideration of his posture in the seat trough the stream video or at the full flight simulator) did not allow making conclusion on its possible impact on the flight outcome.
At the same time the investigation team is of the opinion that the specific features of the HUD indication and display in conditions existed during final phase of the accident flight (severe turbulence, the aircraft upset encounter with the resulting negative G, the significant difference between the actual and the target flight path) that generally do not occur under conditions of the standard simulator sessions, could have affected the situational awareness of the PIC, having been in the highly stressed state.
More information about the flydubai accident can be found on The Aviation Herald website.
