Lima-Callao-Jorge Chávez

It was determined that the crew of the fire truck entered the active runway 16L without prior permission from air traffic controller. This chain of events was caused by the lack of joint planning, poor coordination and the non-use of ICAO-standardized communication and phraseology.

Runway Excursion due to loss of directional control of the aircraft after landing by disengaging the propeller stops for aerodynamic braking at a higher than established speed, which generated an uncontrollable leftward turning moment of the trajectory, due to asymmetric thrust of the propellers.
The following contributing factors were identified:
- Performing a landing on an Unstabilised Approach, not executing the established Go-Around procedure.
- Performing a failed landing due to asymmetric thrust of the propellers, not applying the procedure established in the Operator's QRH to shut down the failed engine.
- Probable failure of the KTA Fuel Regulator of the Automatic Engine Rotation Frequency and Power Regulation System, which blocked the reduction of the power of the N°2 engine to established operating regimes for the approach and landing.

Failure of the mechanical components of the shimmy damper system in each of the main landing gears which, being out of tolerance range, did not allow the correct damping of the vibrations and lateral oscillations of the wheels after touchdown, generating sequential shimmy events in both gears and causing their collapse.
Contributing factors:
- Incorrect and probable absence of measurements on mechanical components of the 'cimmetic chain for shimmy damper operation', as indicated by the operator's PM AMM Task, which would have allowed for the timely detection and replacement of out-of-tolerance components, ensuring their integrity and correct operation.
- The Service Letter 737-SL-32-057-E 'broken torsion link', does not provide for mandatory actions, it only recommends maintenance practices to prevent fractures in mechanical components of the 'cimmetic chain for shimmy damper operation'.
- Service Letter 737-SL-32-057-E 'fractures in lower torsion link', makes a proper interpretation difficult; that could induce errors to choose the corresponding AMM Task and determine its scope.

Unstable approach and inadequate landing technique for high altitude fields, which resulted in increased landing speed, the start of the flare manoeuvre at higher altitude, and low descent speed, which made the OB-2040-P aircraft make soft contact with the runway, causing inefficiency in operation of the shimmy damper, which did not prevent uncontrolled oscillation of the shock absorbers.
Contributing factors:
- Lack of instruction and training in simulators that include techniques and maneuvers of landing at high altitude fields, with emphasis on speed control at landing.
- Lack of a performance analysis process, through the use of flight recorders or other installed data recording equipment and flight parameters, by the operating company, to enable supervision, control and corrective measures in the operational use of its aircraft.

Controlled flight into terrain.

Loss of control following the collision with high power cables after the crew lost visual references during an approach completed in poor weather conditions. The following contributing factors were identified:
- Inadequate meteorological information provided by the Pias Airport flight coordinator that did not reflect the actual weather condition in the area,
- Lack of a procedure card to carry out the descent, approach, landing and takeoff at Pias Airport, considering the visual and operational meteorological limitations in the area,
- The copilot training was limited and did not allow the crew to develop skills for an effective CRM in normal and emergency procedures.

Both engines failed in flight due to icing accumulation and inappropriate use of the deicing systems. The following factors were considered as contributory:
- Poor flight planning on part of the crew,
- Poor crew resources management,
- Poor crew simulator training (icing detection and dual engine failure),
- Lack of procedures relating to icing conditions and dual engine failure,
- Marginal weather conditions which contributed to ice accumulation on engines and airframe.

Erroneous retraction of the landing gear following three bounces on the runway due to an unstabilized final approach and poor crew resource management.
Contributing factors were:
- Although the descent and landing checklists were followed, the crew did not review stabilized approach criteria or procedures for a possible controlled flight into terrain and did not take into consideration the possibility of any go around procedure
- Several call-outs were non-standard while others were missing
- Descent was continued under visual flight rules, approach was unstabilized and not detected by crew
- Speed was too high on touch down while the power levers were not into idle position
- Lack of corrective action on part of the crew when the aircraft was bouncing
- Loss of situational awareness led to the retraction of the landing gear.

One of the engine failed during initial climb for unknown reasons.

The Commission determines the likely cause of the accident as follows:
- The decision of the flight crew to continue the final approach and landing at the airport of Pucallpa in severe weather (storm).
- The decision of the flight crew to descend unstabilized and not act to stop the steep descent to the ground at a descent rate of above 1500 feet per minute; what triggered the GPWS (Ground Proximity Warning System).
- The decision of the flight crew not avoid the storm, not choosing to conduct a landing on the other runway or divert to the nearest airport until weather conditions improved.
- The decision of the flight crew to penetrate the storm, it having been detected on weather radar aircraft approximately 190 miles in advance.
- The loss of the horizontal and vertical visibility of the flight crew while penetrating the core of the storm (severe hailstorm). Severe hail causes obscuration of the front windows of the aircraft and therefore the total loss of situational awareness.