Instrument Flight Rules Procedures and Navigation

Holding Pattern Entry Procedures

Holding patterns are a crucial maneuver in IFR flight. The correct entry procedure depends on your heading as you approach the holding fix.

Parallel Entry

When overhead the holding fix, fly a heading parallel to the holding course on the non-holding side for one minute. Then, make a left turn to intercept the holding course or return directly to the fix.

Teardrop Entry

When overhead the fix, fly a heading 30 degrees off the reciprocal of the holding course on the holding side for one minute. Then, make a right turn to intercept the inbound holding course.

Direct Entry

When overhead the fix, simply turn right and fly the holding pattern as published.

Standard Rate of Turn

A standard rate turn is defined as a turn of 3 degrees per second. At this rate, a complete 360-degree turn takes exactly two minutes.

Flight Instruments

HSI (Horizontal Situation Indicator)

The HSI is a primary flight instrument that combines a heading indicator with a VOR/ILS display.

• Course Pointer: The tip of the main arrow indicates the selected course.
• CDI (Course Deviation Indicator): The entire main arrow, which moves left or right to show deviation from the selected course.
• Tail Pointer: The end of the arrow indicates the reciprocal of the selected course.
• Lubber Line: A fixed white line at the top of the instrument that indicates the aircraft's current magnetic heading.
• The HSI can indicate a VOR radial or a localizer course.

RMI (Radio Magnetic Indicator)

The RMI consists of a compass card and one or two needles that continuously point to radio navigation stations.

• The upper index indicates the aircraft's heading.
• It is often coupled to the HSI.
• Bearing Indicator #1: Single needle.
• Bearing Indicator #2: Double needle.
• The tail of an RMI needle indicates the radial from the station.

RBI (Relative Bearing Indicator)

The RBI indicates the relative bearing to a station, which is the angle between the aircraft's longitudinal axis and the direction of the station.

Instrument Procedures

DME Arc

A DME Arc is a flight path flown at a constant distance from a navigation aid. To initiate a clockwise DME arc, you must turn 90 degrees to the right of the outbound magnetic heading of the lead radial.

• LR (Lead Radial): The initial radial for starting the DME arc.
• IR (Initial Radial): The reference radial used to continue navigating along the arc.

Course Reversal

A course reversal is a maneuver used to establish the aircraft on an inbound course for an instrument approach.

Procedure Turn

This is an IFR procedure where the aircraft flies outbound on a specified radial to a certain distance. A turn is then initiated (left or right) for a specific duration (one minute for Category A/B aircraft or 1 minute 15 seconds for Category C aircraft), followed by a turn in the opposite direction to intercept the inbound course.

Base Turn

A base turn is a course reversal involving a turn from an outbound course to intercept an inbound course, typically without a specified outbound time limit after the turn begins.

Key Aviation Terms

• True Heading: The angle between the aircraft's longitudinal axis and True North.
• Magnetic Bearing: The direction toward the Magnetic North Pole.
• Bearing (BRG): The magnetic heading required to fly directly to the station.

IFR Approach Minimums

CAT I (Category I)

A precision instrument approach with the following minimums:

• DH (Decision Height): 200 feet
• VIS (Visibility): 800 meters
• RVR (Runway Visual Range): 550 meters

ILS (Instrument Landing System)

An ILS is a Precision Approach (PA) system that provides both vertical and horizontal electronic guidance to the runway. The localizer component is referred to as LLZ by ICAO and LOC by the FAA.

Key Components

• Localizer (VHF): Provides horizontal guidance.
• Glideslope (UHF): Provides vertical guidance.

Marker Beacons (VHF)

Marker beacons are radio beacons that help pilots determine their position along the final approach course.

• LOM (Outer Marker): Indicates the aircraft is at the approximate position to intercept the glideslope.
• LMM (Middle Marker): Indicates the approximate decision height point.
• LIM (Inner Marker): Indicates the aircraft is at the decision height for a CAT II approach.

Airport Chart Approach Segments

Instrument approaches are divided into distinct segments:

1. Feeder Route: The segment from the airway system to the Initial Approach Fix (IAF). It is known as a Terminal Route by ICAO.
2. Initial Approach Segment: This segment begins at the IAF and ends at the Intermediate Fix (IF).
3. Intermediate Approach Segment: This segment begins at the IF and ends at the Final Approach Fix (FAF) or Final Approach Point (FAP).
4. Final Approach Segment: This segment begins at the FAF/FAP and ends at the runway or missed approach point. The pilot descends to the Decision Altitude (DA) or Minimum Descent Altitude (MDA) in this segment.