What altitude minimum applies when cleared for LOC RWY 13 after glide slope failure at DSM?

When cleared for the Localizer (LOC) approach to Runway 13 at Des Moines International Airport (DSM) after a glide slope failure, the minimum altitude required is based on the procedure for an approach without a glide slope. The decision to follow a specific altitude is guided by the approach chart for the LOC procedure, which outlines the minimum safe altitude necessary for the aircraft to remain clear of terrain while conducting the approach.

In this particular case, 1,380 feet is the appropriate minimum altitude that applies to this situation. This altitude allows the aircraft to maintain a safe vertical separation from obstacles while aligning with the runway using just the lateral guidance provided by the localizer. Additionally, this minimum is designed to ensure that the aircraft can safely recover from any abnormalities during the approach, contributing to overall flight safety under instrument conditions.

Higher altitudes, such as 1,500 feet or above, do not apply because they exceed the specific requirements set forth in the approach chart for the LOC RWY 13 when the glide slope is unavailable. The procedure specifically defines the minimum necessary to safely navigate the approach path, making 1,380 feet the correct answer.