"I noticed that some instrument approach plates have two missed approaches. How do I know which one to fly?" - Randy P.
“When ATC clears you for an approach, it authorizes you to not only fly the approach but also the missed approach procedure without further clearance. Ground based approaches – ILS, VOR, DME or NDB approaches are designed so the missed approach is based on a different navaid than the primary approach navaid. This requires that whatever ground stations make up the missed approach procedure are available.
If a navaid used on a missed approach procedure was out of service, the entire procedure would become unavailable. Alternate missed approach procedures are a way to get around the failure of one navaid rendering the entire procedure useless even though the primary navaid is still available.
For example, if the missed approach for an ILS is based on flying to a VOR and that VOR was out of service, it would render the ILS unusable even the though the localizer and glide slope are functioning.
So the FAA has developed alternate missed approach procedures for most ground based procedures. The alternate missed approach holding fix is shown in a separate graphic on the plan view of the approach plate. However, to avoid confusion, only the primary missed approach flight path is shown. If the alternate procedure is required, ATC will read it to you. If, for some reason, you are not equipped to fly the alternate missed approach, you will have to negotiate with ATC for a different missed approach or fly a different approach.
Two other points to keep in mind; one – these procedures are only for approaches based on ground based navaids. GPS approaches do not require alternate missed procedures. Second, your GPS will not have the alternate procedure in the database. You may have to suspend the primary missed approach track and manually enter the alternate fixes.”