Instrument Flight
Flight Procedures
You may not commence an instrument approach if weather is below minimums unless: 1) you are dual-
piloted or 2) you are performing a practice approach and do not intend to land. However, if the approach
was above minimums when commenced, you may continue to the published minimums regardless of
changes in the weather. An approach is considered to commence from an enroute descent when leaving
the highest published IAF altitude. For penetration approaches, leaving the IAF is commencing. Before
commencing an instrument approach, complete the penetration checklist, as follows:
MASTER ARM switch: ....................................... SAFE
CONTROL AUG switch: ..................................... ALL
Canopy defog and cockpit temperature: ............. AS REQUIRED
Weather/field conditions: .................................... CHECKED
NAVAIDS: ........................................................... TUNED/IDENTIFIED
Steering Option: .................................................. AS REQUIRED
Positional Data Source: ...................................... AS REQUIRED
Wet Compass, ADI display, HSI display: ............ ALIGNED
Positional Altimeter: ............................................ SET AS REQUIRED
LAW: ................................................................... SET
Fuel: ................................................................... CHECKED
Approach clearance time: ................................... NOTE AND PLAN HOLDING
APPROACH COMMUNICATION PROCEDURES
In your initial communication with approach control, known as P-A-R format, give your Position (if
required) and your Altitude and ATIS letter (information Alpha) and Request an approach. Most often you
will be requesting a specific approach (e.g., High TACAN runway 13). In addition, you may also request
current weather information, the altimeter setting, and the duty runway (WAR), if ATIS is not available. A
prudent pilot would have already tuned and copied ATIS and based his approach request on that
information. If it is not included, then the controller is required to give you the weather. If the letter
identifier is no longer current, the controller will automatically provide you with updated weather
information. In response to your request, approach control will provide clearance, duty runway, surface
wind, ceiling and visibility, current altimeter setting, and missed approach instructions. Whenever the
controller gives you instructions containing headings, altitudes, or an altimeter setting, you are required to
read that information back.
GROUND-CONTROLLED APPROACH (GCA)
There are two basic types of ground-controlled approaches—the precision radar approach (PAR) and the
surveillance radar approach (ASR). A PAR provides you with precise course, glidepath, and range
information and is classified as a precision approach. An ASR (commonly referred to as a surveillance
approach) provides lower resolution course and range information only (no glideslope) and is classified as
a non-precision approach.
NOTE: Glideslope is defined as the descent angle assigned to an approach to a given runway for
obstacle clearance and/or signal reception. Glidepath is defined as the portion of a precision approach
that intercepts the azimuth of an ILS approach or the FAC of a PAR approach.
Both the PAR and ASR approaches are divided into two segments: initial pattern and final approach.
Refer to (Figure 37) for an illustration of the GCA pattern.
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