A preliminary investigation by safety officials has found that poor pilot training was at fault in the 13 April Lion Air crash in Indonesia.

A preliminary investigation by safety officials has found that poor pilot training – not windshear – was at fault in the recent Lion Air crash in Indonesia, raising concerns about human error and the role it plays in air crashes.

On 13 April, two pilots operating a Lion Air Boeing 737 undershot a runway at Ngurah Rai Airport and crashed into the waters off Bali. Preliminary findings from the investigation found that a 24-year-old captain could not see the runway upon descent and was forced to hand over control of the plane to a co-captain at 46m – below the minimum altitude considered safe. While a full investigation is not yet complete, the preliminary findings have ruled out any fault with the aircraft.

Pilot error refers to any action or decision – or lack of proper action – made by a pilot that plays a role in an accident. This may include a simple mistake, a lapse in judgment or failure to exercise due diligence. There are two types of pilot error, according to Aviation Safety Magazine: tactical errors, which are related to a pilot’s poor actions or decisions, often caused by fatigue, inebriation or lack of experience; and operational errors, related to problems with flight instruction and training. In the case of the Lion Air incident, it appears both lack of experience and poor training may have played a part.

In fact, pilot error is the leading cause of commercial airline accidents, with close to 80% percent of accidents caused by pilot error, according to Boeing. The other 20% are mainly due to faulty equipment and unsafe, weather-related flying conditions.

Although policies put in place to reduce pilot error are not universal across the world, there are varying guidelines about how long a pilot can captain a flight, how many co-pilots should be present and how many hours a pilot can fly before taking mandatory breaks. There are also varying guidelines about how many hours of training pilots must complete, below what altitude they should not hand over control of a plane and when they should abort landings.

The investigation report has recommended that Lion Air implement several safety measures, including reviewing “the policy and procedures regarding the risk associated with changeover of control at critical altitudes or critical time”.