Martinair Flight 495

On the morning of the accident, the plane was delayed at Amsterdam Airport Schiphol because of a faulty thrust-reverser. This was not fixed. Nevertheless, the plane took off to Faro at 7:30 am. According to Martinair, the faulty thrust-reverser was not a contributing factor in the accident.

A large thunderstorm lay in the immediate vicinity of Faro airport, accompanied by heavy rain, windshear and low cloud. The control tower informed the crew of the thunderstorm activity, in addition stating that there was water on the runway. Following one unsuccessful attempt to land, the crew was executing a VOR/DME procedure approach to runway 11 (now runway 10) when the aircraft flew through at least two microbursts. According to the Portuguese final accident report, firefighters saw an explosion coming from the aircraft 22 seconds before it crashed.

The aircraft landed with a vertical speed exceeding the manufacturer's design limits. Following this hard landing, the starboard main gear collapsed. The starboard wing fuel tank ruptured and the contents ignited. The DC-10 fuselage split in two, coming to rest with the front section lying on its side.

According to the Portuguese aviation authorities (DGAC), the causes of the air disaster were likely:[1]

• the high sink rate in the last phase of the approach;
• the landing on the right landing gear, which exceeded the structural limitations of the aircraft;
• the transverse wind during the final approach and landing, before the landing was stronger than allowed for a landing on a flooded runway;
• the combination of both factors caused forces that were greater than the aircraft could handle.

The DGAC describes as additional factors:

• the instability of the approach;
• bringing it back too early and letting it be too low, probably because of the crew's actions;
• providing incorrect wind information by the approach control line;
• the absence of an approach light system;
• the incorrect assessment of the condition of the runway by the crew;
• the dropping of the autopilot just before the landing, whereby the aircraft was flown by hand in a critical phase of the landing;
• delaying the crew in increasing the ability;
• the decrease of the lift coefficient due to heavy rainfall.

The Dutch Office for the Investigation of Accidents and Incidents of the National Aviation Authority (RLD) indicated that the probable cause should be as follows:[1]

• a sudden and unexpected variation in wind direction and speed (windshear) in the last phase of the approach;
• then there was a high descent speed and extreme lateral displacement, which caused a hard landing on the right landing gear, which in combination with a considerable angular displacement exceeded the structural limitations of the aircraft.

According to the RLD, additional factors were:

• that the crew of flight MP495 did not expect the occurrence of windshear on the basis of the weather forecast and the weather;
• the premature reduction and reduction of engine power, most likely due to the action of the crew;
• the dropping of the autopilot just before the landing, whereby the aircraft was flown by hand in a critical phase of the landing.

On 14 February 2011, the Algemeen Dagblad reported among other things about a new investigation, which was carried out by researcher Harry Horlings at the request of relatives.[5] According to Horlings, there was no wind shear at the Faro disaster and the pilots had made serious mistakes.[6] According to Horlings, the data from the black box was incomplete in the Dutch report from 1993; the last seconds were missing.[7][8] In the cover letter to the report of the American Aviation Service, in which the data from the black box were presented, it was indicated that the autopilot had been used incorrectly. The report also recommended improving the training of pilots.[9]

The Dutch Safety Board stated that it was unable to respond because the Council had not been able to view and assess the report from researcher Horlings. Attorney Jan Willem Koeleman, who assisted some of the surviving relatives, announced that he would request Martinair to recognize liability and pay additional compensation.[6] On 8 December 2012, Koeleman reported Martinair and the Dutch state to complain before the 21st of that month. After that date the case would be barred.[10]

The case against Martinair, which had meanwhile become part of KLM, finally served on 13 January 2014 in Amsterdam.[11] On February 26, 2014, the court rendered judgment. She had ignored the new facts presented by the victims and ruled that additional damages were not necessary.[12]

The case against the State of the Netherlands served on 20 January 2014 in The Hague.[11] On the same day on which the District Court ruled in Amsterdam, 26 February 2014, a decision was also made here by means of an interlocutory judgment. Unlike the court in Amsterdam, the court in The Hague deemed further investigation necessary and wished to hear experts.[12]

In January 2020, the District Court of the Hague ruled that the Dutch state was partly responsible for the accident.[13]