The Minimum Descent Altitude (MDA) is the lowest altitude, expressed in feet above mean sea level (MSL), to which an aircraft may descend on a non-precision instrument approach without having the required visual references for landing in sight. The MDA is designed to provide a safe vertical buffer above obstacles until a missed approach is initiated or a landing is made.

• Ensure obstacle clearance during the final segment of a non-precision approach
• Define the limit of descent without visual contact with the runway
• Support decision-making between continuing visually or executing a missed approach

• Non-precision approaches (e.g., VOR, NDB, RNAV (LNAV), LOC)
• Circling approaches, where maneuvering to a runway other than that aligned with the approach is required
• Visual segments after some RNAV or step-down approaches

• “Minimum descent altitude 1,200 feet.”
• “Holding MDA until missed approach point.”
• “No contact at MDA, going around.”

You may descend below MDA only when:

• ✅ The runway environment is clearly in sight (e.g., runway lights, markings, threshold)
• ✅ You can make a normal descent and landing
• ✅ Visibility is equal to or better than the required minimums

• ✅ Begin level-off early to avoid busting MDA
• ✅ Use altitude callouts and checklists during final approach
• ✅ Practice MDA scenarios in LearnATC's non-precision modules
• ✅ Always know your aircraft category and refer to the correct minima column on the approach chart

• Missed Approach Point (MAPt) – the point at which you must decide to land or go around
• OCH (Obstacle Clearance Height) – used in calculating MDA
• Circling MDA – higher minima used when circling to a different runway