Brazil

It was determined that the n°3 leading edge flap actuator attachment fitting on the wing front spar had fractured due to corrosion. The actuator came away and caused the failure of some hydraulic lines and damage to the thrust control cables. Some 1981 Boeing Service Bulletins had not been complied with. One of these included the replacement of the aluminium leading edge flap actuator attachment fitting with a steel one; this had not been done. The following contributing factors were reported:
- Excessive workload on approach and landing due to the emergency situation,
- Poor approach planning,
- Lack of visibility due to the night,
- Poor crew coordination,
- Poor crew resources management,
- The crew forgot to lower the flaps electrically on approach, causing the speed to be 32 knots in excess,
- Poor aircraft maintenance and supervision,
- Failures in the supervision of the Company's operating sector.

It was determined that a fire of unknown origin erupted in flight, followed by several explosions. A that time, a load of ammunition was stored in several boxes in the cargo compartment.

It was determined that the hydraulic pump n°2 on the engine n°3 failed after takeoff, causing an oil leak and a loss of hydraulic pressure. The undercarriage could be lowered but not locked down while the crew attempted to lower the nose gear manually but doing so, caused the locking pin to obstruct and damage the landing gear extension system. It was also reported that several seals located on hydraulic lines were broken and have not been replaced during the last C check.

It was determined that the evening prior to the accident, the aircraft suffered an incident upon landing at Feijó Airport. Upon landing the copilot inadvertently mishandled the engines. Reverse pitch was not applied. Directional control was lost and the left main landing gear ran off the side of the runway. The airplane came to rest 40 metres past the runway end. It was towed to the ramp and the captain conducted an inspection of the airplane. As nothing wrong was noticed, the crew decided to continue the flight after the company base was notified of the occurrence. At the time of the accident, the crew was anxious about the event that occurred the preceding evening and the captain's attention was distracted. Thus, there was a higher level of stress in the cockpit at the time of the accident and the copilot did not want to be the PIC for the second leg due to anxiousness. As the right engine was totally destroyed by a post crash fire, it was not possible to determine the exact cause of its malfunction. Poor weather conditions, poor flight planning and insufficient control inputs on the rudder were considered as contributing factors.

Contributing factors
a. Human Factor
(1). Psychological Aspect
It contributed, since the pilot in command adopted an improvisational attitude through the adoption of unforeseen procedures in the face of the insistence on landing, despite the weather conditions present. A likely channeling of attention to external references may have contributed to the loss of operational performance, leading to the loss of the maintenance condition of the basic flight parameters.
(2). Physiological Aspect
Undetermined since the absence of interference from toxicological factors was not effectively verified.
b. Material Factor
Didn't contribute.
c. Operational Factor
(1). Deficient Instruction
It contributed since there was no periodic simulator training and also no cockpit resource management (CRM) training.
(2). Deficient Supervision
It contributed since there was no adequate monitoring of the circumstances of operation by the Company's operations sector and, also, there were no defined and clear rules and specific operating routines that adequately addressed the various aspects of the operation.
(3). Little Flight or Aircraft Experience
It contributed because of the small experience in the aircraft by the copilot.
(4). Influence of the Environment
It contributed since visibility was limited at the time of the accident.
(5). Deficient Cockpit Coordination
Contributed since there was no briefing to the accomplishment of the descent procedure by instruments, the copilot did not follow the execution of the procedures after the critical point since he concentrated his attention to the search of external references, thus abandoning the monitoring of the flight parameters.
(6). Disabled Infrastructure
Indetermined since the influence of the low accuracy of the NDB on the heading lags occurred in the descent procedure was not perfectly established and no effective test was performed.
(7). Poor Planning
It contributed because there was no briefing in the procedure of descent by instrument and approach lost.
(8). Deficient discipline of Flight
The pilot therefore continued the flight, without visibility, at an altitude below the minimum for this operating condition.
(9). Adverse Weather Conditions
It contributed as the prevailing weather conditions were marginal, with the aerodrome closed for IFR operation.

The accident was the consequence of the following factors:
1) Adverse Weather Conditions - Contributed
Weather conditions were unfavorable at the destination location for visual flight. There was a layer of fog near the forest.
2) Poor Instruction - Contributed
The Commander was not qualified to fly that type of aircraft and was not instrument cleared.
3) Disabled Judge - Contributed
The pilots continued the flight, even knowing the adverse weather conditions at their destination.
4) Flight Indiscipline - Contributed
One of the pilots was not qualified to fly that aircraft and, in addition, there was intentional disobedience to the air traffic rules and regulations, regarding the non observance of the minimum IFR flight level in the industry.
5) Disabled Oversight - Contributed
There was poor oversight of the responsible company by letting an unqualified pilot operate the aircraft.
6) Weak Cabin Coordination - Contributed
IFR flight without complying with IMA 100-12 rules, conducted below the limits and outside the descent profile are indications that there was no planning/coordination in the operations performed in the cockpit.

The following findings were reported:
- There was a deficiency in the instruction received, since the crew did not perform emergency training on that type of aircraft, resulting in inadequate preparation for the engine failure situation, especially at low altitude,
- There are indications that the maintenance services were inadequate and contributed to the occurrence of engine failure, due to the possible occurrence of compressor stall,
- The company performed inadequate technical and operational oversight for not providing emergency situations for the crews of that type of aircraft involved in the accident.