Where Birds Don't Fly

Changing an instrument arrival procedure to a steeper-than-standard approach slope in order to reduce flight cancellations appears, at first glance, to be a practical operational solution. In a mountain valley airport in the Canadian Rockies, operators often experience persistent weather systems, terrain shielding, and rapidly changing winds. It is understandable that an airport authority may wish to increase reliability and airline confidence by designing an approach that keeps aircraft higher above terrain longer and allows descent closer to the runway threshold. However, modifying an instrument procedure primarily to influence completion rates rather than to preserve stable, predictable flight conditions introduces a systemic safety hazard. Aviation safety depends on standardization, predictability, and pilot expectation. A steeper-than-standard slope undermines all three simultaneously. Standard instrument approach slopes exist for a reason. The typical 3-degree glide path is not a...