Landing (descent or approach)

The following findings were identified:
- The LEFT MAIN LANDING GEAR ASSEMBLY (PN D23189000-19 and SN MN1700) collapsed, failing with 5,130 cycles after the last overhaul.
- A specific component (pin) of the assembly connecting the landing gear to the airframe, the AFT PIVOT PIN (P / N D61000, S / N 25), broke on account of fatigue, whose onset was facilitated by a machining process carried out in the pin section transition region.
- The ANAC-approved ATR72 Series Aircraft Maintenance Program of the TRIP Linhas Aéreas company read that the LEFT MAIN LANDING GEAR ASSEMBLY had to undergo overhaul every eight years or 18,000 cycles.
- On 27 February 2009, the PR-TTI landing gear was removed and, on 09 March 2009, was sent to be overhauled by the AV Indústria Aeronáutica Ltda. It had 31,684 cycles since new and 18,095 cycles since the last overhaul.
- AV Indústria Aeronáutica Ltda. was homologated for conducting such inspection, as specified in the List attached to the Addendum, Revision no. 11, dated 05 January 2009, and accepted by means of the Official Document no. 0173/2009-GGAC/SAR, issued by the Civil Aviation Authority.
- The AV Indústria Aeronáutica Ltda. company disassembled the legs of the landing gear, and outsourced some of the tasks for not possessing technical knowledge and/or appropriate machinery (necessary for the process of reconditioning the AFT PIVOT PIN (D61000 SN 25).
- Two of the three companies outsourced by AV Indústria Aeronáutica Ltda. were not homologated by the Civil Aviation Authority.
- The AV Indústria Aeronáutica Ltda. company conducted external audits of the three companies involved in the overhaul.
- The audits carried out by AV Indústria Aeronáutica Ltda. were not sufficient to identify that the contractors lacked qualified personnel, manuals and the machinery necessary to work with aeronautical products.
- The AV Indústria Aeronáutica Ltda. Technical Manager did not supervise the overhaul inspections and services performed by the contracted companies.
- The AFT PIVOT PIN (D61000 SN 25) is part of the assembly that connects the landing gear to the airframe.
- All revision tasks were described in the manuals of the manufacturer.
- The AFT PIVOT PIN (D61000 SN 25) failure-analysis report stated that the PRTTI aircraft left main landing gear collapsed on account of fatigue, whose onset was facilitated by a machining process carried out in the section transition region of the pin.
- The manufacturer's maintenance manual did not refer to any machining work in that region of the pin.
- In only one stage of the pin reconditioning process was it possible to observe that a machining task was required, namely, the Grinding of chromium.
- The lack of capacitation and training of the subcontractors’ professionals for handling aircraft material hindered the execution of an efficient maintenance work as prescribed by the manufacturer's manual, culminating in inadequate machining during the maintenance process.
- The lack of an effective process of supervision, both on the part of TRIP Linhas Aéreas and on the part of the other contractors and subcontractors allowed the existing maintenance services’ latent failures not to be checked and corrected, in a way capable of subsidizing, in an adequate and safe manner, the execution of the landing gear maintenance service.
- The process of supervision of the TRIP Linhas Aéreas and the AV Indústria Aeronáutica Ltda. companies by the Civil Aviation Authority, prescribed by specific legislation in force, was not enough to mitigate the latent conditions present in the accident in question.
- According to the technical opinion issued by the DCTA, the AFT PIVOT PIN (D61000 and SN 25) presented fracture surfaces with ± 45º inclination, as well as a flat area with multiple initiations, indicative of a fracture mechanism related to fatigue. In examinations of the external surface of the pin, in a region close to the fatigue fracture, cracks were observed that had initiated from scratches created by an inadequate maintenance machining process. In the region where the overload-related fracture occurred, it was also possible to identify that the machining process had modified the profile of the part in the section transition region, by producing a depression. Thus, it can be said that the AFT PIVOT PIN (D61000 and SN 25) of the PR-TTI left main gear broke on account of fatigue, whose onset was facilitated by an inadequate machining process that had been performed in the section transition region of the pin.

Loss of control during an attempted go-around initiated below Decision Height (200 feet) in Instrument Meteorological Conditions.
The following factors were considered as significant:
- The approach was continued in conditions of poor visibility below those required.
- The descent was continued below the Decision Height without adequate visual reference being acquired.
- Uncoordinated operation of the flight and engine controls when go-around was attempted
- The engine power-levers were retarded below the normal in-flight operational range, an action prohibited in flight.
- A power difference between the engines became significant when the engine power levers were retarded below the normal in-flight range.
- Tiredness and fatigue on the part of the Flight Crew members.
- Inadequate command training and checking.
- Inappropriate pairing of Flight Crew members, and
- Inadequate oversight of the remote Operation by the Operator and the State of the Operator.

The aircraft crashed into the sea following a possible in flight upset associated with a loss of control during IMC conditions.
The following contributory factors were identified:
- Deviation from standard operating procedures by the crew not flying the published cloud-break procedure for runway 30 at FAPG, but instead opted to attempt to remain visual with the ground/sea (comply with VMC requirements) by descending over the sea and approaching the aerodrome from the southeast (Robberg Nature Reserve side).
- Inclement weather conditions prevailed in the area, which was below the minima to comply with the approved cloud-break procedure for runway 30 at FAPG (minimum safety altitude of 844 feet according to cloud-break procedure) as published at the time of the accident.
- Judgement and decision making lacking by the crew. (The crew continued from the seaward side with the approach during IMC conditions and not diverting to an alternative aerodrome with proper approach facilities timeously although a cell phone call in this regard indicate such an intention).
- The possibility that the pilot-flying at the time became spatially disorientated during the right turn while encountering / entering IMC conditions in an attempt to divert to FAGG should be regarded as a significant contributory factor to this accident.
- This was the first time as far as it could be determined that the two crew members flew together.

The exact cause of the accident remains unknown as no investigation was completed by the NTSB.

The following findings were identified:
- Factors, such as obesity and sedentariness, associated with the high workload in the moments preceding the collision with the hill, may have contributed for the task demand to exceed the margins of safety, resulting in wrong decision-making by the pilot.
- Upon facing adverse meteorological conditions and being aware that aircraft which landed before him had reached better visibility in altitudes below 3,500 ft. on the final approach of the VOR procedure, the pilot may have increased his level of confidence in the situation, to the point of descending even further, without considering the risks involved.
- The weather conditions encountered in the final phase of the flight may have aggravated the level of tension in the aircraft cabin to the point of compromising the management of the situation by the pilot, who delegated responsibility for radiotelephony communication to a passenger.
- If one considers that the pilot may have decided to descend below the minimum safe altitude in order to achieve visual conditions, one may suppose that his decision, probably influenced by the experience of the preceding aircraft, was made without adequate evaluation of the risks involved, and without considering the option of flying IFR, in face of the local meteorological conditions. In addition, the pilot’s decision-making process may have been compromised by lack of information on Mount Santo Antonio in the approach chart.
- The primary radar images obtained by Anápolis Control (APP-AN) indicated the presence of thick nebulosity associated with heavy cloud build-ups on the final approach of the VOR procedure. Such meteorological conditions influenced the occurrence, which culminated in the collision of the aircraft with Mount Santo Antônio, independently of the hypotheses raised during the investigation.
- The final approach on the course 320º, instead of 325º, made the aircraft align with the hill with which it collided.
- Mount Santo Antonio, a control obstacle on the final approach in which the collision occurred, was not depicted in the runway 32 VOR procedure approach chart, in discordance with the prescriptions of the CIRTRAF 100-30, a fact that may have contributed to a possible decrease of the situational awareness.

Bad weather conditions for the aircraft and inappropriate actions by cockpit crew to confront the situation is the main cause of the accident. The following contributing factors were identified:
- The old technology of aircraft systems,
- Absence of a suitable simulator for adverse weather conditions,
- Failure to correctly follow the operating manual by the flight crew,
- Inadequate cockpit resources management (CRM).

The pilot’s decision to conduct an instrument approach in icing conditions without the anti-ice system activated, contrary to the airplane flight manual guidance, which resulted in an inadvertent aerodynamic stall due to an in-flight accumulation of airframe icing.

The pilot's misjudgment of the runway surface condition, resulting in an aborted landing and collision with rising terrain during the ensuing takeoff attempt.