Martinair Flight 495 was a McDonnell Douglas DC-10 operated by Dutch airline Martinair, that crash-landed in severe weather conditions at Faro Airport, Portugal on 21 December 1992. The aircraft carried 13 crew members and 327 passengers, mainly holidaymakers from the Netherlands. 54 passengers and 2 crew members died. 106 of the other occupants were badly injured.
Aircraft and crew
The aircraft involved was a McDonnell Douglas DC-10-30CF, registered PH-MBN, which was built in 1975 carrying the serial number 46924. The aircraft was named Anthony Ruys in honor of one of Martinair's former commissioners. It was delivered to Martinair on 26 November 1975. However, Martinair leased it out to three Asian airlines from October 1979 to September 1981. From then on until the accident, it was solely operated by Martinair, only disrupted in early 1992 by a short lease to World Airways. Earlier in 1992, it had been sold to the Royal Netherlands Air Force for a planned conversion to a KDC-10.
The captain was 56-year-old H. Willem van Staveren, who had been with Martinair since January 1968. He was a DC-10 flight instructor with a total of 14,441 flight hours. He previously served in the Royal Netherlands Navy from 1962 to 1966 and had worked for Schreiner Airways from 1966 to 1968.
The first officer was 31-year-old Ronald J. H. Clemenkowff. He had been with Martinair for three years with 2,288 flight hours, 1,787 of them on the DC-10.
The flight engineer was 29-year-old Gary W. Glans, who had been with Martinair for only eight months. However, he had worked for both Canadian Airlines and Swissair from 1988 to 1992. Glans had a total of 7,540 flight hours, including 1,700 hours on the DC-10.
Description
Departure
On the morning of the accident, the plane was delayed at Amsterdam Airport Schiphol due to a faulty thrust-reverser. This was not fixed. Nevertheless, the plane left for Faro at 04:52 UTC. According to Martinair, the faulty thrust-reverser was not a contributing factor in the accident.
Crash
A large thunderstorm had developed near Faro airport, accompanied by heavy rain, windshear and low cloud. The control tower informed the crew of the thunderstorm activity, in addition to stating that there was water on the runway. Following one unsuccessful landing attempt, the crew attempted a VOR/DME procedure approach to runway 11 (later runway 10), during which 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 made a hard landing with a vertical speed exceeding the manufacturer's design limits. Following this, the starboard main gear collapsed, the starboard wing separated from the fuselage and the starboard 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.
Causes
Opinions differ as to the cause(s) of this disaster.
Official investigation by Portuguese aviation authorities
According to the Portuguese aviation authority (DGAC), the cause(s) were likely to have been:
high sink rate in the last phase of the landing approach; hard landing on the right landing gear, exceeding its structural limitations; transverse wind during the final approach and landing that exceeded the design limits of the landing gear, given the flooded condition of the runway;
The DGAC describes the following additional factors:
instability of the landing approach; pilots' reducing throttle too early and allowing the aircraft to lose altitude in an unsafe manner; airport providing incorrect wind information for the approach; absence of an approach lighting system; incorrect assessment of the condition of the runway by the crew; overriding of the autopilot just before the landing, whereby the aircraft was flown manually in a critical phase of the landing; delay by the crew to increase altitude; decrease of the aircraft's lift coefficient due to heavy rainfall.
Dutch aviation authorities
The Dutch Office for the Investigation of Accidents and Incidents of the National Aviation Authority (RLD) indicated that the probable cause(s) could be as follows:
a sudden and unexpected variation in wind direction and speed (windshear) in the last phase of the approach; a high descent speed and extreme lateral displacement that caused an excessive loading of 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: