Pilot 'miscalculated rate of descent'

AN AER Lingus pilot miscalculated the rate of descent on his approach to Chicago and had to pull up quickly, an Air Accident Investigation Unit (AAIU) report has concluded.

A report into the incident, which occurred two years ago today, found that the pilot was 774 feet (235 metres) below where he should have been on his approach to Chicago O’Hare airport.

The AAIU said the pilot miscalculated the rate of descent required and descended too rapidly.

Earlier he had been given clearance at O’Hare airport for an instrument landing system approach to the runway which involves the aircraft following a precise path laid out by air traffic control.

However, that order was followed by one seeking a non-precision or non-instrument landing system approach, which led to the approach being too steep.

On realising that it was too low, power was increased and subsequently go-around power was selected for a short period, though it was not needed and the aircraft, with 307 passengers and crew, made a normal landing.

AAIU inspector Paddy Judge was critical of the fact that the incident was not reported until nearly four months after it happened, by which time most records concerning the flight had been discarded.

Mr Judge concluded that the primary cause of the incident was an incorrect rate of descent, but he also found that a late change of approach had not allowed sufficient time for the crew to adjust.