Landing (descent or approach)

The aircraft landed at Virgin Gorda in conditions (of weight, altitude, temperature and surface condition) where the landing distance required was very close to the landing distance available and without the required safety margin. Hence, when the performance of the brakes was not as expected, probably due to debris in the braking system, the aircraft could not be stopped on the runway. Analysis of the maintenance state of the aircraft involved in this accident indicated that the maintenance capability, processes and planning of its operator were not consistent with the standards expected in conducting international passenger charter services. This appeared also to be the case for the operational procedures and data management.

The pilot's failure to ensure that the landing gear were down and locked before touchdown. Contributing to the accident was the pilot's self-reported fatigue at the time of the accident.

Contributing factors:
- Adverse meteorological conditions - a contributor
At the moment of the impact of the aircraft, there was rain with rainfall potential of 25mm/h, covering the Paraty Bay region, and the horizontal visibility was 1,500m. Such horizontal visibility was below the minimum required for VFR landing and take-off operations. Since the SDTK aerodrome allowed only operations under VFR flight rules, the weather conditions proved to be impeding the operation within the required minimum safety limits.
- Decision-making process - a contributor
The weather conditions present in SDTK resulted in visibility restrictions that were impeding flight under VFR rules. In this context, the accomplishment of two attempts to approach and land procedures denoted an inadequate evaluation of the minimum conditions required for the operation at the Aerodrome.
- Disorientation - undetermined
The conditions of low visibility, of low height curve on the water, added to the pilot stress and also to the conditions of the wreckage, which did not show any fault that could have compromised the performance and/or controllability of the aircraft, indicate that the pilot most likely had a spatial disorientation that caused the loss of control of the aircraft.
- Emotional state - undetermined
Through the analysis of voice, speech and language parameters, variations in the emotional state of the pilot were identified that showed evidence of stress in the final moments of the flight. The pilot's high level of anxiety may have influenced his decision to make another attempt of landing even under adverse weather conditions and may have contributed to his disorientation.
- Tasks characteristics - undetermined
The operations in Paraty, RJ, demanded that pilots adapt to the routine of the operators, which was characteristic of the executive aviation. In addition, among operators, possibly because of the lack of minimum operational requirements in SDTK, the pilots who landed even in adverse weather conditions were recognized and valued by the others. Although there were no indications of external pressure on the part of the operator, these characteristics present in the operation in Paraty, RJ, may have favored the pilot's self-imposed pressure, leading him to operate with reduced safety margins.
- Visual illusions - undetermined
The flight conditions faced by the pilot favored the occurrence of the vestibular illusion due to the excess of "G" and the visual illusion of homogeneous terrain. Such illusions probably had, consequently, the pilot's sense that the bank angle was decreasing and that he was at a height above the real. These sensations may have led the pilot to erroneously correct the conditions he was experiencing. Thus, the great bank angle and the downward movement, observed at the moment of the impact of the aircraft, are probably a consequence of the phenomena of illusions.
- Work-group culture - a contributor
Among the members of the pilot group that performed routine flights to the region of Paraty, RJ, there was a culture of recognition and appreciation of those operating under adverse conditions, to the detriment of the requirements established for the VFR operation. These shared values promoted the adherence to informal practices and interfered in the perception and the adequate analysis of the risks present in the operation in SDTK.

The pilot's attempted landing on the ice-covered runway, which resulted in a runway excursion and impact with terrain. Contributing to the accident was airport personnel's lack of training regarding issuance of NOTAMs

The cause of the Boeing 747-412F TC-MCL aircraft accident was the missing control of the crew over the aircraft position in relation to the glideslope during the automatic approach, conducted at night in the weather conditions, suitable for ICAO CAT II landing, and as a result, the measures to perform a go-around, not taken in due time with the aircraft, having a significant deviation from the established approach chart, which led to the controlled flight impact with terrain (CFIT) at the distance of ≈930 m beyond the end of the active RWY.
The contributing factors were, most probably, the following:
- the insufficient pre-flight briefing of the flight crew members for the flight to Manas aerodrome (Bishkek), regarding the approach charts, as well as the non-optimal decisions taken by the crew when choosing the aircraft descent parameters, which led to the arrival at the established approach chart reference point at a considerably higher flight altitude;
- the lack of the crew's effective measures to decrease the aircraft vertical position and its arrival at the established approach chart reference point while the crew members were aware of the actual aircraft position being higher than required by the established chart;
- the lack of the requirements in the Tower controllers' job instructions to monitor for considerable aircraft position deviations from the established charts while the pertinent technical equipment for such monitoring was available;
- the excessive psycho-emotional stress of the crew members caused by the complicated approach conditions (night time, CAT II landing, long-lasting working hours) and their failure to eliminate the flight altitude deviations during a long time period. Additionally, the stress level could have been increased due to the crew's (especially the PIC's) highly emotional discussion of the ATC controllers' instructions and actions. Moreover, the ATC controllers' instructions and actions were in compliance with the established operational procedures and charts;
- the lack of the crew members' monitoring for crossing the established navigational reference points (the glideslope capture point, the LOM and LIM reporting points);
- the crew's failure to conduct the standard operational procedure which calls for altitude verification at the FAF/FAP, which is stated in the FCOM and the airline's OM. On the other hand, the Jeppesen Route Manual, used by the crew, contains no FAF/FAP in the RWY 26 approach chart;
- the onboard systems' "capture" of the false glideslope beam with the angle of ≈9°;
- the design features of the Boeing 747-400 aircraft type regarding the continuation of the aircraft approach descent in the automatic mode with the constant descent angle of 3° (the inertial path) with the maintained green indication of the armed automatic landing mode (regardless of the actual aircraft position in relation to the RWY) while the aircraft systems detected that the glideslope signal was missing (after the glideslope signal "capture"). With that, the crew received the designed annunciation, including the aural and visual caution alerts;
- the absence of the red warning alert for the flight crew in case of a "false" glideslope capture and the transition to the inertial mode trajectory, which would require immediate control actions from the part of the crew;
- the lack of monitoring from the part of the crew over the aircraft position in regard to the approach chart, including the monitoring by means of the Navigation Display (ND), engaged in the MAP mode;
- the crew's failure to conduct the Airline's Standard Operational Procedures (SOPs), regarding the performance of the go-around procedure in case the "AUTOPILOT" (the AP switching to the inertial mode) and "GLIDESLOPE" (the EGPWS annunciation of the significant glideslope deviation) alerts during the automatic CAT II landing at true heights below 1000 ft (with no visual reference established with either the runway environment or with the lighting system);
- the delayed actions for initiating the go-around procedure with no visual reference established with the runway environment at the decision height (DH). In fact, the actions were initiated at the true height of 58 ft with the established minimum of 99 ft.

The pilot's loss of directional control during the aborted landing in gusting crosswind conditions, which resulted in a runway excursion.

The pilot's loss of airplane control due to spatial disorientation, which resulted in the exceedance of the airplane's critical angle of attack and an aerodynamic stall/spin. Contributing to the accident was the pilot's failure to fly a stabilized approach consistent with the published instrument approach procedure.

Contributing Factors:
- The visual illusion of aircraft higher than the real altitude resulted in late flare out which made the aircraft bounced.
- The unrecovered bounce resulted in abnormal landing attitude with vertical acceleration up to 6 g and collapsed the right main landing gear.