Boeing 737-200

The following factors were reported:
- The flight crew allowed the aircraft to descend significantly below the normal approach glide path during a Surveillance Radar Approach to runway 23 at Coventry Airport, in conditions of patchy lifting fog. The descent was continued below the promulgated Minimum Descent Height without the appropriate visual reference to the approach lighting or the runway threshold.
- The standard company operating procedure of cross-checking altimeter height indications during the approach was not observed and the appropriate Minimum Descent Height was not called by the non handling pilot.
- The performance of the flight crew was impaired by the effects of tiredness, having completed over 10 hours of flight duty through the night during five flight sectors which included a total of six approaches to land.

Failure of maintenance personnel to follow the taxi checklist resulting in the hydraulic pumps not being turned on.

Loss of control after rotation due to application of wrong rudder by trainee pilot during engine failure exercice. The instructor did not guard/block the rudder control and give clear commands as instructor so as to obviate the application of wrong rudder control by the trainee pilot.

The probable cause of accident has been attributed to :
- Pilots' error in initiating late rotation and following wrong rotation technique, and
- Failure of the NAA to regulate the mobile traffic on the Beed road during the flight hours.

Aborted takeoff and subsequent overran and destruction of the aircraft following the failure of both tyres on the right main gear during takeoff. The following contributing factors were reported:
- The flight schedule with reduced time scales and short 'stopover' failed to allow the necessary cooling of wheels and brakes, giving rise to the deflation and subsequent destruction of the tyre n°4 and the explosion and destruction of the tyre n°3,
- Limited braking action on the landing gear assembly,
- Partial knowledge and ignorance of the times and procedures for cooling the wheels by the pilots,
- Delay in the departure of the flight, with respect to the scheduled time,
- Difficulty in appreciating at San Luis Airport during a night takeoff, visual references of runway,
- Lack of concern during the takeoff abort on part of the pilots.

The following findings were reported:
a. Human Factor
(1) Physiological Aspect
- There was no evidence of this aspect contributing to the occurrence of the accident.
(2) Psychological Aspect - Contributed
- The psychological aspect contributed through the generation of a high level of anxiety to perform the landing and in the diversion of the focus of attention during the approach manoeuvres to land.
- The psychological aspect was influenced by the activation of the smoke alarm which generated an increase in the workload on board.
b. Material Factor
- There were no indications that this factor contributed to the accident.
c. Operational Factor
(1) Deficient Instruction
- Although the instruction was carried out in accordance with what the standards recommend, the failures that contributed to the accident are characteristic of lack of experience in facing abnormalities simultaneously with the maintenance of flight control. Such failures could be avoided with more adequate simulator instructions and training involving the cockpit management aspects.
(2) Poor Maintenance - Undetermined .
- It was not possible to determine the cause of the activation of the 'Aft Cargo Smoke' alarm and whether the maintenance services contributed to this occurrence.
(3) Deficient Cockpit Coordination
- Inadequate performance of the duties assigned to each crew member. The procedures foreseen for the execution of descent by instrument have been modified and some have been deleted depending on the appearance of a complicator element (smoke alarm).
(4) Influence of the environment
- The dark night contributed to the creation of the 'black hole' phenomenon, or 'background figure', making it difficult to perceive external references for a possible identification of the vertical distance of the aircraft from the ground.
(5) Deficient Oversight
- The supervision, at cockpit level, contributed to the accident by the inadequate management of the resources available for the flight in the cockpit.
- Company level supervision contributed to the accident by not identifying the need for cockpit management training and providing it to the crew involved.
- Supervision, at company level, was also inadequate when climbing to the same mission, two pilots unfamiliar with the airplane to be used and in night operation.
(6) Other Operational Aspects
- The failure to comply with several 'Callouts', the non-use of the radio altimeter and the inadequate use of the 'altitude alert', as an aid to the accomplishment of the descent procedure, contributed to the occurrence of the accident.

The following findings were reported:
- Loss of control of the aircraft because the flight crew followed false information from an attitude indicator that operated intermittently.
- Lack of visible horizon during cruise flight due to night and approaching bad weather.
- Insufficient cross-checking between the primary and emergency (standby) attitude indicators to identify intermittent attitude errors and to select a reliable source of (correct) attitude information.
- Non-standard cabin configurations between aircraft in the fleet of the company, which required the crew to determine how to set the switches based on the aircraft was being operated at the time.
- Incomplete ground crew training simulator, as it did not present 'differences between aircraft' and 'crew resource management' in sufficient detail to give the crew knowledge to overcome intermittent attitude indicator errors and to maintain control of the aircraft.