You have certainly been assigned once for a circling approach by the Air Traffic Control. Do you actually know what you're supposed to do? Well, if you don't - you will find it out now!

A Circling Approach is a "difficult" procedure and should be avoided when able (consider landing with a little tailwind); some airlines even prohibit circling at all! Normally it is required when conditions are IMC and the instrument approach is either not runway aligned or the approach is for a non suitable runway. For this tutorial I'll pick up San Francisco Intl. ILS 28L approach and circle-to-land on 19R.

First of all you need to check on the bottom of the charts the circling minimums for that approach. This is a non-precision approach, so you will have a minimum descent altitude (MDA), rather than a decision height (DH). Once MDA is set, you should continue on the glideslope until you reach it. You must not begin circling unless you have the runway in sight. If you loose sight of the airport, than you must carry out the missed approach procedure immediately; do not go below MDA if you don't have visual contact! Once you got visual contact, begin turning downwind (parallel to the runway), then base and final (just like an ordinary traffic pattern) - remember to stay within the circling area. Set landing flap before turning base leg and descend to intercept visual glidepath on final. Then, accomplish normal landing

This is a short briefing of the approach, in a Boeing 737: I started the approach at MENLO, following both LOC and GS until MDA. ATC cleared me for a left traffic approach to 19R, so I stayed at MDA until 2.5 miles from the runway and began my turn to enter downwind, using flap 15 and gear down until turning base, where I selected flap 30. While turning to final approach, I began my normal descent down to the runway. The picture below shows a rough diagram of the procedure.

While circling, DO NOT:
- Hit the ground
- Loose visual reference
- Go outside the circling area

Use the chart below to determine your circling area:



Missed approach

If a missed approach is required at any time while circling, turn towards the approach runway to reach the missed approach heading, even if the turn is more than 180 degrees and not in the shortest direction. Maintain the missed approach flap setting until close-in maneuvering is completed. Different patterns might be required to become established on the prescribed missed approach course - this will depend on the airplane's position at the time the missed approach is started.

Figure below illustrates two ways to ensure the airplane will remain within the circling area while performing the missed approach.