Quito-Mariscal Sucre (City)

The Board of Inquiry estimated that the probable cause of this accident was the crew's decision to continue the approach and landing without carrying out the procedures (ABNORMAL AND EMERGENCY PROCEDURES) established by Embraer in the Quick Reference Handbook when a malfunction occurred with the slat/flap system, resulting in a wrong approach configuration.
The following findings were identified:
- The slats were inoperative during the approach and the crew performed five trouble shooting without success,
- Despite this situation, the crew decided to continue the approach, failed to follow the approach checklist and failed to input the reference speed and distance for landing according to circumstances,
- The aircraft landed too far down the runway, about 880 metres past the runway 35 threshold,
- The braking action was low because the runway surface was wet,
- In normal conditions, with flaps down in second position and slats out, the landing reference speed was 119 knots with a landing distance of 880 metres,
- Because the slats were inoperative, the landing reference speed should be 149 knots and a landing distance of 1,940 metres was needed,
- The aircraft passed over the runway threshold at a height of 50 feet and at an excessive speed of 163,8 knots,
- Spoilers were activated 9 seconds after touchdown, 950 metres after the runway threshold,
- Reverse thrust systems were activated 1,280 metres after the runway threshold,
- The crew started to use brakes 2,300 metres after the runway threshold (runway 35 is 3,125 metres long), with the antiskid system activated,
- Due to an excessive approach speed (15 knots above Vref), a too long flare and a too late application of the brake systems, the aircraft could not be stopped within the remaining distance,
- The slats malfunction was the consequence of the failure of several actuators which did not support negative temperatures met during the last flight,
- Since last July 19, the slats failed 53 times on this aircraft, six times during the approach and 47 times in flight,
- The crew failed to initiate a go-around procedure.

Wrong approach configuration on part of the crew who decided to continue the approach to Quito Airport, knowing the poor runway conditions, poor weather conditions and the aircraft weight, and his failure to initiate a go-around procedure while forcing the aircraft to intercept the PAPI, causing the aircraft to be unstabilized.
Contributing factors:
- On the date of the incident, the crew did not have specific regulations and operating procedures (the briefing of the operator for the airport in Quito was inappropriate to the existent conditions).
- The fact that the crew still being experienced similar airports in Quito and had not experienced similar weather situations, circumstances that would have allowed a strategy of approximation consistent with the terms of this operation, in particular as regards:
- Calculations in flight for landing runway length,
- Minimum altitude to start the maneuver of changing the path of ILS to PAPI,
- Carrying out a very detailed briefing that allowed unwanted deviations on approach,
- The weather conditions existing at the time of landing (visibility, tail wind and moderate rain).

Lack of a positive actions and reaction on part of the crew following the bursting of both tires on the left main gear, causing the aircraft to overrun the runway.

It is believed that the crew failed to follow the taxi and pre-takeoff checklist and forgot to select the switches for the hydraulic valves of the control system. No technical anomalies were found on the aircraft and engines.

At the time of the accident, the total weight of the aircraft was 69,620 kilos, some 9,700 kilos above the MTOW. The crew had been told by the operator that MTOW was 70,000 kilos.

The accident was the consequence of the failure of the electrical system.

The incorrect position of the horizontal stabilizer in relation to the aircraft's centre of gravity, which prevented the aircraft from reaching rotation and lift-off speed within the runway distance available. The following contributing factors were reported:
- Clearance of the aircraft from Quito was done incorrectly, since the MTOW permissible for the existing runway, wind and temperature conditions, the real take-off weight, the useful load distribution and the position of the aircraft's centre of gravity were not determined,
- The crew's state of mind may have been a contributing factor in the accident. It is assumed that it prevented the crew from concentrating on all aspects of the operation they were performing.