São Paulo

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 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.

The exact cause of the accident could not be determined with certainty. However, the following findings were reported:
- a. Human Factor
(1) Undetermined Physiological Aspect
Given the characteristics of the accident, which resulted in the destruction of the bodies, making it impossible to carry out examinations, it cannot be specified whether it contributed or not. However one cannot rule out the possibility that one of the crew members has been affected by a sudden illness (2nd Hypothesis of the Analysis).
(2) Psychological Aspect - Undetermined
It may have influenced, to the extent that the commander was operating an aircraft in which he had little experience and little knowledge, and which was demonstrated by the insecurity in the operation, reported to other pilots.
b. Material Factor
(1) Design Deficiency - Undetermined
Despite the information provided by representatives of Learjet Corp. who participated in the investigations, that the compensator engine ('pitch trim') with which this aircraft was equipped, had already undergone the modifications determined by the Federal Aviation Administration (FAA), one cannot help but wonder about a possible firing and locking of the 'pitch trim' engine in the extreme position (3rd Hypothesis of the Analysis). This aspect was hampered as the destruction suffered by the aircraft made a detailed analysis of the pitch trim system impossible.
c. Operational Factor
(1) Disabled Instruction - Contributed.
The commander and the co-pilot received a less than desired instruction, in quantitative and qualitative terms. As a result, the pilots did not acquire the full technical conditions necessary for the proper operation of the aircraft. The failure to perform the standard procedure to be followed in the emergency that led to the accident, i.e. the lowering of the landing gear, attests to the poor instruction given.
(2) Deficient Application of Controls: - Contributed
The pilots did not adjust the engine power properly after leveling and, after the aircraft started to abruptly descend, as a result, the 'overspeed' occurred, they could not avoid the loss of control.
(3) Weak Cockpit Coordination - Contributed.
The pilots made inadequate use of the aircraft's resources for its operation.
(4) Forgetfulness - Contributed.
This aspect is in accordance with the previous one, since the lowering of the undercarriage is part of the standard procedure to be performed in cases of overspeed.
(5) Little Flight Experience in the Aircraft - Contributed
The captain, despite having 6,500 hours of flight time, had already intended to fly another jet plane, but had flown little on Learjet. The other pilot, in turn, had had less experience in jet flying as a co-pilot, and in the Learjet, specifically, flew less than the commander.
As a result, when they were faced with an emergency that required rapid identification in order to take the necessary measures to remedy it, they lacked the necessary experience.
(6) Deficient Supervisor - contributed.
The air taxi company, to which the pilots belonged, was in a hurry to train this new crew. This resulted in inadequate operational training for the pilots, which demonstrates poor supervision of the company. The Civil Aviation System, through the regional body that deals directly with general aviation, failed to carry out proper oversight, as it did not detect the errors in the statements of instruction, and allowed the checks of the captain and the co-pilot to be carried out without reaching the minimum amount of flight hours and landings on that aircraft.

Controlled flight into terrain after the crew decided to continue the descent under VFR mode in IMC conditions. It was reported that the wrong approach configuration adopted by the crew caused the aircraft to enter a valley which was not mentioned on approach charts. Due to poor visibility because of low clouds, the crew was unable to distinguish the mountain struck by the aircraft. The crew was misled by external factors inherent to weather conditions.

The accident was the consequence of a poor approach planning and wrong approach configuration.
The following contributing factors were reported:
- Deficiencies in crew training,
- Deficiencies in flight controls,
- Poor crew coordination,
- Poor judgment,
- Poor planning,
- Lack of supervision.

The accident was the consequence of the combination of the following factors (findings):
- The imminent interruption of operations in the aerodrome that would be used for landing the aircraft (closure of runway 09R due to works) stimulated the instructor to make a hurried descent, characterizing a potential state of anxiety,
- Probable crew fatigue,
- The instruction given to the pilot was discontinued and the local flight did not comply with the minima provided in RAC 3211,
- The failures found in the instruction were due to poor supervision of the Company's operations sector,
- Poor crew coordination,
- During the descent procedure when working checklist, the instructor broke the sequence of standardized procedures, thus stopping the instruction and consequently, the student's core handling of the flight,
- The instructor, without the student being informed beforehand, commanded the flaps together with the speed brakes. This action configured an abnormal attitude that contributed, without the pilots identifying, to the loss of control of the aircraft,
- The flight engineer also failed to meet the checklist items,
- The instructor did not follow the standardization of the instruction, when he executed a decision in a hurry,
- The crew did not respond to the sinking and pull up warnings,
- Error in the application of flight controls,
- The crew did not operate in accordance with the operational standard issued by the manufacturer and endorsed by the company,
- The air traffic controller contributed to the increase of the crew anxiety level by using non standard phraseology.

The following findings were reported:
- The pilots did not plan the flight properly, though there was an AIS room with the necessary sources of consultation. Maintaining altitude of 5000 feet for too long a time, subject to the minimum safe altitudes in the are area in the available publications, and the discrepancies found in the flight plan confirm this thesis.
- The pilot did not properly collated the guidelines issued by the tower and remained incompatible altitude with instructions issued by the control.
- There are strong indications that the flight proceeded under instrument flight conditions.
- There was no proper coordination between the ACC BS and TWR SJ regarding the transference and control of the air traffic nor did TWR SJ requested receipt of the messages.

Failure of the crew to recognize that he was lined up on a taxiway and not the active runway. Poor visibility due to foggy conditions was a contributing factor.