MDA vs. DA Made Simple: A Guide to IFR Minimums
Learn the difference between MDA and DA, how IFR approach minimums work, and when pilots level off or go missed during instrument approaches.
MDA and DA are both IFR approach minimums, but they are used differently. The short version is this: MDA is an altitude you do not descend below until the required visual references are available. DA is a decision point where you either continue visually or begin the missed approach.
That difference matters because it changes how you fly the final part of the approach.
What Minimums Do
Instrument approaches are designed to help pilots descend toward an airport when visibility or ceilings are reduced. Minimums protect obstacle clearance near the bottom of the approach. If the chart layout itself still feels busy, start with how to read an IFR approach chart.
If you do not have the required visual references by the appropriate point, you do not keep descending. You execute the missed approach.
For training, do not treat minimums as vague suggestions. Brief them clearly and say them out loud before the approach begins. A consistent instrument approach briefing keeps the number tied to the action.
What MDA Means
MDA stands for minimum descent altitude. It is used on non-precision approaches and circling approaches.
On an approach with an MDA, you descend to the published MDA, level off, and continue toward the missed approach point. If the required visual references are in sight and you can make a normal descent to landing, you may continue below MDA. If not, you stay at or above MDA until the missed approach point, then go missed.
The key phrase is level off. MDA is not a point where you automatically go missed the moment you arrive. You may continue at MDA to the missed approach point if the procedure allows.
What DA Means
DA stands for decision altitude. It is used on precision approaches and many approaches with vertical guidance.
On an approach with a DA, you are normally descending on a glide slope or glide path. When you reach DA, you make the decision: continue to land if the required visual references are available and the aircraft is in a position to land safely, or go missed.
The key phrase is decide and act. You do not level off and fly along at DA.
What About DH?
DH means decision height. It is similar to DA, but it is measured as height above a reference point rather than altitude above mean sea level.
Most student instrument training focuses on DA and MDA. DH is more common in specialized operations with specific equipment and training. Still, understanding the idea helps: altitude is read from the altimeter; height is measured above a surface or reference.
Which Approaches Use Which?
Non-precision approaches, such as many VOR or localizer-only procedures, commonly use MDA. Circling minimums use MDA because the pilot must remain visual while maneuvering.
Precision approaches, such as ILS approaches, use DA. RNAV approaches with approved vertical guidance may also use a DA-style minimum depending on the line of minimums used.
Always read the approach plate. Do not assume the minimum type from memory or habit. This is especially important on RNAV approaches, where the line of minimums you use depends on equipment, approval, and procedure details.
How to Brief MDA
Before an MDA approach, brief:
- Final approach course.
- Step-down fixes and altitude restrictions.
- MDA.
- Missed approach point.
- First missed approach instruction.
- Required visibility and visual references.
During the approach, avoid descending below step-down altitudes early. When you reach MDA, level off accurately and prepare for either a normal descent to landing or the missed approach.
How to Brief DA
Before a DA approach, brief:
- Final approach course.
- Glide slope or glide path intercept.
- DA.
- Missed approach procedure.
- Required visual references.
- Autopilot or hand-flying plan.
As you approach DA, avoid last-second confusion. The callout should already be expected. At DA, make the decision and transition promptly.
Common Student Mistakes
One mistake is treating MDA like DA and going missed early when it may be appropriate to continue to the missed approach point at MDA. Another is treating DA like MDA and trying to level off at the decision altitude.
Students also sometimes brief the number but not the action. Do not just say "minimums 720." Say what you will do there.
Visual References Still Matter
Seeing something outside does not automatically mean you may continue. You need the required visual references and you must be in a position to make a normal descent to landing.
If the runway environment appears late, off to the side, or in a way that requires an unstable maneuver, go missed.
The Practical Difference
MDA means descend, level, look, then decide by the missed approach point. DA means descend on guidance, decide at DA, and continue or miss.
That simple distinction will make approach briefings cleaner and reduce workload in the clouds. Know which minimum you are using before you start down final, not when the callout arrives.
Official References
Need help applying this to your training?
Use this guide as a starting point, then bring the confusing parts to a focused ground lesson. Diego works with Louisville-area and remote students on FAA knowledge, oral-prep, and practical training decisions.
Related guide collections
- Instrument Rating Guides - Plain-language instrument rating guides for IFR procedures, approach briefing, holding, currency, and instrument training decisions.
- IFR Procedures Guides - IFR procedure guides for approach charts, approach briefings, holding, IFR clearances, ILS, VOR, RNAV, minimums, and instrument currency.