INSTRUMENT PROCEDURES HANDBOOK
 

MISSED APPROACH

Many reasons exist for executing a missed approach. The primary reason, of course, is that the required flight visibility prescribed in the IAP being used does not exist or the required visual references for the runway cannot be seen upon arrival at the DA, DH or MAP. In addition, according to Part 91, the aircraft must continuously be in a position from which a descent to a landing on the intended runway can be made at a normal rate of descent using normal maneuvers, and for operations conducted under Part 121 or 135, unless that descent rate will allow touchdown to occur within the touchdown zone of the runway of intended landing. [Figure 5-22] CAT II and III approaches call for different visibility requirements as prescribed by the Administrator.

Once descent below the DA, DH, or MDA is begun, a missed approach must be executed if the required visibility is lost or the runway environment is no longer visible, unless the loss of sight of the runway is a result of normal banking of the aircraft during a circling approach. A missed approach procedure is also required upon the execution of a rejected landing for any reason, such as men and equipment or animals on the runway, or if the approach becomes unstabilized and a normal landing cannot be performed. After the MAP in the visual segment of a nonprecision approach there may be hazards when executing a missed approach below the MDA. Any missed approach after a DA, DH, or MAP below the DA, DH, or MDA involves additional risk until established on the published missed approach procedure course and altitude.

At airports with control towers it is common for ATC to assign alternate missed approach instructions; even so, pilots should always be prepared to fly the published


Figure 5-21. Determination of Visibility Minimums.


Figure 5-22. Operation Below DA, DH, or MDA.

missed approach. When a missed approach is executed prior to reaching the MAP, the pilot is required to continue along the final approach course, at an altitude above the DA, DH, or MDA, until reaching the MAP before making any turns. If a turn is initiated prior to the MAP, obstacle clearance is not guaranteed. It is appropriate after passing the FAF, and recommended, where there aren’t any climb restrictions, to begin a climb to the missed approach altitude without waiting to arrive at the MAP. Figure 5-23 gives an example of an altitude restriction that would prevent a climb between the FAF and MAP. In this situation, the Orlando Executive ILS or LOC RWY 7 approach altitude is restricted at the BUVAY 3 DME fix to prevent aircraft from penetrating the overlying protected airspace for approach routes into Orlando International Airport. If a missed approach is initiated before reaching BUVAY, a pilot may be required to continue descent to 1,200 feet before proceeding to the MAP and executing the missed approach climb instructions. In addition to the missed approach notes on the chart, the Pilot Briefing Information icons in the profile view indicate the initial vertical and lateral missed approach guidance.

The missed approach course begins at the MAP and continues until the aircraft has reached the designated fix and a holding pattern has been entered, unless there is no holding pattern published for the missed approach. It is common at large airports with high traffic volume to not have a holding pattern depicted at the designated fix. [Figure 5-24 on page 5-35] In these circumstances, the departure controller will issue further instructions before the aircraft reaches the final fix of the missed approach course. It is also common for the designated fix to be an IAF so that another approach attempt can be made without having to fly from the holding fix to an IAF.

As shown in Figure 5-25 on page 5-36, there are many different ways that the MAP can be depicted, depending on the type of approach. On all approach charts it is depicted in the profile and planviews by the end of the solid course line and the beginning of the dotted missed approach course line for the “top-line”/lowest published minima. For a precision approach, the MAP is the point at which the aircraft reaches the DA or DH while on the glide slope. MAPs on nonprecision approaches can be determined in many different ways. If the primary NAVAID is on the airport, the MAP is normally the point at which the aircraft passes the NAVAID.

On some nonprecision approaches, the MAP is given as a fixed distance with an associated time from the FAF to the MAP based on the groundspeed of the aircraft. A table on the lower right hand side of the approach chart shows the distance in NM from the FAF to the MAP and the time it takes at specific groundspeeds, given in 30- knot increments. Pilots must determine the approximate groundspeed and time based on the approach speed and true airspeed of their aircraft and the current winds along the final approach course. A clock or stopwatch should be started at the FAF of an approach requiring this method. Many nonprecision approaches designate a specific fix as the MAP. These can be identified by a course (LOC or VOR) and DME, a cross radial from a VOR, or an RNAV (GPS) waypoint.

Obstacles or terrain in the missed approach segment may require a steeper climb gradient than the standard 200 feet per NM. If a steeper climb gradient is required, a note will be published on the approach chart plan view with the penetration description and examples of the required FPM rate of climb for a given groundspeed (future charting will use climb gradient). An alternative will normally be charted that allows using the standard climb gradient. [Figure 5-25 on page 5-36] In this example, if the missed approach climb requirements cannot be met for the Burbank ILS RWY 8 chart, the alternative is to use the LOC RWY 8 that is charted separately. The LOC RWY 8, S-8 procedure has a MDA that is 400 foot higher than the ILS RWY 8, S-LOC 8 MDA, and meets the standard climb gradient requirement over the terrain.

 
 
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