All of the relevant markings and lighting on Runway 24L met the standards for runway marking and lighting contained in Chapter 5 of TP 312E.

On the day of the occurrence, the runway lights at TNCM were off and the PAPI lights were at 30%.

Since the approach was conducted in daylight in good visibility conditions, the absence of runway lighting was not identified as a threat.

ADM signed an agreement to this effect with the Montréal Control Tower defining the conditions for closure of a runway in the event of inoperative components of the runway lighting.

Runway lighting systems enable pilots to locate the runway during landing, to touch down in the right place, to maintain the aircraft on the runway centreline, and to evaluate the distance to the end of the runway.

Given the absence of runway lighting in reduced visibility conditions, it was difficult for the pilot flying to detect the lateral movement of the aircraft over the runway and therefore to prevent the runway excursion.

Given the absence of runway lighting in reduced visibility conditions, it was difficult for the PF to detect the lateral movement of the aircraft over the runway and therefore to prevent the runway excursion.

The flight crew saw neither the runway lights nor the PAPI lights during the approach, and did not request that the intensity of the lights be increased.

The low-intensity setting of the runway lights and precision approach path indicator lights limited the visual references that were available to the crew to properly identify the runway.

The lights that make up the runway lighting system enable pilots to locate the runway during landing, to touch down in the right place, to stay in the centre of the runway, and to evaluate the distance to the end of the runway.

The low intensity of the runway edge lights and PAPI lights and the lack of visual cues over water were not identified as threats.

When set at the appropriate intensity, runway lights and PAPI lights can fulfil the level of sensory conspicuity required to serve as visual references.

Realizing that visibility was declining due to moderate to heavy rain showers, the controller turned the runway lights on to an automatic setting for night use.

Consequently, the crew had not anticipated that the risk of losing sight of the runway due to reduced visibility through the windshield in the rain would be exacerbated by the absence of runway lighting.

However, due to the outage of the runway and approach lighting systems, the decision height (DH) was increased by 50 feet and minimum visibility increased by ¼ sm over the published approach minimums.

The low intensity of the runway lights and PAPI lights reduced their effectiveness as a visual reference and limited the likelihood that they would capture the attention of the flight crew in the crew's visual scan.