Operations with an ILS glidepath angle that exceeds what degree is prohibited?

Operations with an Instrument Landing System (ILS) glidepath angle that exceeds 3.5 degrees are prohibited due to established safety and operational standards. The 3.5-degree limit is set to minimize the risk during approach and landing phases, as steeper glidepaths can lead to increased descent rates, making it more challenging for pilots to maintain control of the aircraft. Additionally, steeper approaches can reduce the margin for error during landing, particularly concerning terrain and obstacle clearance.

Glidepath angles of more than 3.5 degrees could also pose issues related to aircraft performance, as many aircraft are not designed for the instability that can occur during steep approaches. Following this limitation helps ensure that the approach remains within the operational envelope of the aircraft and aligns with standard procedures for safety in aviation operations.