Air carrier flight crew reported they received a low altitude alert from ATC on approach into CYUL and cited differences in Canadian and U.S. approach charts as contributing.
Synopsis
Air carrier flight crew reported they received a low altitude alert from ATC on approach into CYUL and cited differences in Canadian and U.S. approach charts as contributing.
Narrative
We were cleared '3;000; cleared for the approach' The airplane was already on LNAV and VNAV. I accidentally put the G/S intercept altitude shown in the approach plate briefing strip (which is wrong because Canada does it differently as the final approach fix/glide slope intercept altitude is not the one listed on the briefing strip of the Jeppesen chart). I had marked the glide slope intercept location in the Nav page in the MCDU (Multipurpose Control Display Unit) so that I can identify it. I also briefed the Canada differences. But out of habit; I accidentally put the wrong altitude. As we crossed the IF at 3000 ft. (as ATC told us to do); the airplane started to PTH (Pitch) down. ATC told us to check altitude because we were low. I immediately stopped the descent; checked altimeter; and made sure that we were at a safe altitude (we were about 2300 ft). At this point we already had the runway in sight. I realized that we were below the shaded altitude portion of the approach plate (Canada). By the time I made sure all of the former; the airplane caught the glide slope and we re cleared to land. We landed safely.Bugging the wrong altitude for the glide slope intercept; which made the airplane PTH down earlier than it should in this approach and ultimately went below the shaded portion of the approach plate. Complacency as I have done many flights to this airport and never once made this mistake. Early show time. Briefing the Canada differences and not cross-checking. The habit of using the glide slope intercept/FAF altitude from the Jeppesen briefing strip and not taking a closer look at the profile of the approach. Not executing a go-around the second ATC issued a low altitude alert. Cross-check altitudes better and confirm with the approach plate.
Second reporter narrative
We were low on the approach to 6R into CYUL. The differences in the chart layout between US and Canadian approaches; led to an altitude lower than the glide-slope. Visual conditions; altitude corrected; safe normal landing.The difference between US and Canadian approach plate layouts; Canadians do not associate a waypoint with glide-slope intercept. As far as I know every single ILS in the US has a waypoint associated with glideslope intercept.Approach plates should be uniform all over the world.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.