Why did the aircraft go so close to the hills? Several explanations are being dished out, but the most commonly heard of in the aviation circles say that the pilot while circling for Runway 12 was on Flight Management Computer, but instead of following the prescribed route he had probably created a 'visual circuit using place bearing distance waypoints' that put him in the wrong place. - File Photo.

In intimation to A-320 operators across the world, Airbus said there was no need to update the procedures or make fresh recommendations after the ED 202 crash because all flight systems were working normally before the aircraft slammed into the fog-covered mountains.

All 152 passengers on board were killed.

The advisory was based on a preliminary analysis of flight data recorder and cockpit voice recorder by Bureau d'Enquetes et d'Analyses.

A final outcome of the investigation may take months, but preliminary investigations have set the direction for the probe.

According to aviation experts, the Airbus communication implies that technical malfunctioning has been effectively ruled out as the cause of the incident and it is up to the investigation team constituted by the Civil Aviation Authority to determine if the crash occurred because of pilot error, bad weather, control tower fault or any other factor.

The cockpit voice recording readouts have also revealed that the pilots belatedly realised that they were flying into terrain. The first officer of the flight was heard screaming “Sir, pull up, pull up” moments before the crash.

This revelation has been supported by the findings of local investigators which show that before hitting the mountains the aircraft had climbed from 2,600 feet to 3,100 feet. The aircraft was circling for Runway 12, where it was to attempt visual landing. Sources privy to the investigations believe the pilot got panicked after realising that he was flying into the terrain and had turned the autopilot 'heading bug' to the left at more than 180 degrees. The aircraft, experts say, takes the shortest possible route in such situation and instead of turning left moved towards right.

Why did the aircraft go so close to the hills? Several explanations are being dished out, but the most commonly heard of in the aviation circles say that the pilot while circling for Runway 12 was on Flight Management Computer, but instead of following the prescribed route he had probably created a 'visual circuit using place bearing distance waypoints' that put him in the wrong place.

Insertion of place bearing distance waypoints is strictly prohibited by aircraft manufacturers because the Airbus FMC does not have a 'fix page' capability, wherein a defined distance can be superimposed on the existing route. The standard instructions are that any route that is not supported by a ground navigational aid should not be used.