Approaches

Instrument Approach Procedure

A series of predetermined maneuvers for the orderly transfer of an aircraft under instrument flight conditions from the beginning of the initial approach to a landing or to a point from which a landing may be made visually. It is prescribed and approved for a specific airport by a competent authority. Designed for IFR use in IFR conditions, may also be executed in VFR conditions.

U.S. Criteria

Approach charts reflect the criteria associated with the United States Standard for Terminal Instrument Approach Procedures (TERPs)

US Military Criteria

Established and published by the DOD and are available upon request

IAP charts

Provide the method to descend and safely in low visibility conditions.

Four Segments of an Instrument Approach

Initial

Intermediate

Final

Missed

Initial Approach Segment

The first part of an IAP is the segment between the Initial Approach Fix (IAF) and the Intermediate Fix (IF) or the point where the aircraft is established on the intermediate course or final approach course.

Intermediate

The second part of an IAP is The segment between the IF and the Final Approach Fix (FAF). May consist of an extended portion of the final approach course prior to reaching the FAF.

Final Approach Segment

The third part of an IAP is the segment between the FAF Cand the runway, airport, or Missed Approach Point (MAP). Begins at the FAF, and ends at a point from which a safe landing can be made or at the beginning of a missed approach procedure.

Missed Approach Segment

The last part of an IAP is the segment between the MAP or the point of arrival at Decision Altitude (DA) or Decision Height (DH) and the missed approach fix at the prescribed altitude. Consists of a climb to a safe altitude and usually a turn or a heading to a point where the aircraft will enter holding. Established for every instrument approach. Positively identifies the exact point when the final approach must be abandoned, and the missed approach procedure initiated

Under which conditions may an aircraft execute an Instrument Approach Procedure?

Instrument or visual

The three primary categories of IAP’s:

Precision, With Vertical Guidance, Nonprecision

Precision

provide both lateral and vertical guidance with a groundbased support infrastructure. Instrument Landing System (ILS), Precision Approach Radar (PAR), Ground Based Augmentation System (GBAS), Landing System (GLS) are examples of this type of IAP.

With Vertical Guidance

APVs provide both lateral and vertical guidance without the requirement for a ground-based support infrastructure. (RNAV [GPS]) and (RNAV Required Navigation Performance [RNP]) are examples of this type of IAP.

Nonprecision

provide lateral course information only. Example of this type of IAP are Localizer (LOC), Omni-Directional Range (VOR), Very High Frequency Omnidirectional Range/Distance Measuring Equipment (VOR/DME), Tactical Air Navigation (TACAN), Global Positioning System (GPS), Non-Directional Radio Beacon (NDB), and Airport Surveillance Radar (ASR).

Instrument Landing System

Provides precision navigation guidance for exact alignment and descent of aircraft on approach to a runway.

Primary components of an ILS

Localizer, Glideslope, Marker Beacons

Supplementary Components

Approach Lights, Compass Locators, DME

Localizer

Provides horizontal (left/right) guidance along the extended centerline of the runway

Glideslope (GS)

Provides vertical (up/down) guidance toward the runway touchdown point, usually at a 3° slope

Marker Beacons

Provide range information along the approach path

Approach Lights

Assist in the transition from instrument to visual flight

Compass Locators

An NDB on the final approach course that tells the pilot where they are on the ILS

DME

Is generally collocated with the localizer when used as a component of the ILS; however, other locations may be used if they provide improved coverage or operational benefits

If the GS component of an ILS approach is inoperative, the remainder of the procedure is classified as a __ approach

localizer

An ILS approach is __ if the localizer is out of service

not usable

The ILS is designed to provide _

an approach path with lateral and vertical guidance

Which of the following components of an ILS is designed to provide the pilot with course guidance to the runway centerline?

Localizer

Landing System (GLS)

provides precision navigation guidance for exact alignment and descent of aircraft on approach to a runway. Also provides guidance similar to ILS approaches for the final approach segment.

GBAS

developed as an “ILS look−alike” system, from the pilot perspective, to provide GLS precision approaches at select airports

RNAV (GPS) approach

Uses GPS signals, often augmented by Wide Area Augmentation System (WAAS) and/or an approach certified Barometric Vertical Navigation (Baro-VNAV) system, for guidance.

Baro-VNAV

uses barometric altitude information from the aircraft’s pitot-static system and air data computer to compute vertical guidance for the pilot.

RNAV (RNP) Approach

Based on GPS signals and WAAS/Baro-VNAV. Requires on-board navigation performance monitoring and alerting capability to ensure that the aircraft stays within a specific containment area. Some of these approaches have a curved path, also called a radius to fix leg. Not all aircrafts are able to perform this approach.

What are the nonprecision approaches?

VOR/DME approach

LOC approach

VOR approach

TACAN approach

NDB approach

ASR approach

VOR/DME approach

More accurate than VOR approach because of the range/distance guidance provided by the DME.

LOC Approach

An approach that uses only the localizer component of an ILS system

VOR approach

Provides a radial to be intercepted and tracked, which leads to the airport. The approach may be to a specified runway or simply to the airport with a circling approach to a runway.

TACAN approach

Used only by the military; provides azimuth and distance, similar to VOR/DME approach.

NDB approach

Provides a non-directional bearing that a pilot uses to fly a course to an airport. This approach is the least accurate of the instrument approaches.

ASR approach

An approach conducted with surveillance radar that provides azimuth and range only. The approach is conducted with Air Traffic Control (ATC) personnel communicating with the pilot via radio.

An approach is termed “nonprecision” because it _____.

Provides only lateral course guidance

__ approaches utilize WAAS and GPS signals.

RNAV

Instrument Approach Procedure Charts

portray the aeronautical data that is required to execute IAPs to airports. Commonly referred to as “approach plates.”

All IAPS except ___ and ___ approaches are depicted using the same general format.

Precision Approach Radar (PAR), Airport Surveillance Radar (ASR)

IAP charts are commonly referred to as ___

Approach Plates

Margin Information

is located at the top and bottom of the chart which depicts the airport location and procedure identification.

IAPs are listed alphabetically in the US Terminal Procedures Volumes, first under ___, then under __

city, airport

Civil approach plates are organizaed by ___, ___. and ___

city, airport, state

Military approaches are organized by ____ name first.

airport

At the _____, the airport’s latitude and longitude coordinates are provided

bottom center

City and state are located at the ___ of the margin information.

top left and bottom left

The reference number and approving authority is at the ____ of the margin information

top center

Procedure name, airport name, and airport identifier is at the ___ of the margin informaiton

top right

How are civil approach plates organized?

city/airport name

Pilot briefing

located at the top of the chart and provides the pilot with the information required to execute the published approach procedure

What is in the pilot briefing information?

Localizer information

Approach Course

Available landing distance

Runway environment elevations

Notes and Limitations

Full Text description of missed approach

Frequencies listed in normal order of use

If a T symbol appear in the notes section it means

the airport has nonstandard IFR takeoff minimums

If a “A” symbol appears in the notes section it means

the airport has nonstandard IFR alternate minimums.

What are some types of information that can be found in the pilot’s briefing section of an IAP?

Landing distance, Localizer Information, and frequencies

Planview

provides a graphical overhead view of the procedure. Could include transition routes, geographical landmarks, and alternate missed approach fix.

Minimum Safe Altitude (MSA)

emergency altitude to be used within 25 nautical miles (NM) of the NAVAID upon which the approach is predicated. Ensures 1,000 feet of obstruction clearance but does not ensure NAVAID frequency reception.

Terminal Arrival Area (TAA)

Found on some RNAV approach charts. Replaces the MSA and provides minimum altitudes with standard obstacle clearance depending upon the direction from which the aircraft is arriving. Based on a 30-mile radius of the IAF. Allows aircraft to transition from the en route structure direct to the nearest IAF. Eliminates or reduces feeder routes, departure extensions, and procedure turns or course reversal

Basic T Design

Ideally aligns the procedure with the runway centerline to include the Missed Approach Point located at the threshold. Includes a Final Approach Fix (FAF) 5 NM from the threshold and an Intermediate Fix (IF) 5 NM from the FAF.

The Basic T usually incorporates

2 IAFs located 3 to 6 NM on either side of the final IF/IAF and approximately 90° to the final approach course. The leg length or angle of the turn to the intermediate segment may be modified when required by obstructions or airspace.

What are some types of information that can be found in the planview section of an IAP?

Middle marker, Procedure turn, transition routes, and inbound course

TAA is based on a __ mile radius of the IAF.

30

Airport diagram

gives detailed information about the layout of the airport. helps pilots identify the MAP on certain nonprecision approaches

Information that can be found on the airport diagram section of an approach plate:

airport elevation

obstructions

Runway lights available

Final approach fix (FAF) distance

Time/speed table

Touchdown zone elevation

displaced threshold

Which of the following items is included in an airport diagram?

Airport elevation

Missed Approach Icons

Part of the profile view and provide a visual depiction of the instructions for conducting the missed approach procedure.

Profile view

includes missed approach and shows a side view of the IAP.

Profile view of a precision approach contains the following items:

Missed approach icons

Altitude of the glideslope at the LOM

FAF

Courses of the IAP to be flown

Minimum procedure turn altitude

Decision Altitude (DA)

Missed Approach Point (MAP)

Missed Approach Track shown as a dashed line

Distances

Glidepath

Minimum glideslope intercept altitude

Threshold Crossing Height (TCH) in feet AGL

Glideslope descent angle

FAF can be detected by

a lightning bolt, matese cross

Lightning bolt means

when flown a full ILS approach with glideslope

Maltese cross means

when flown as a localizer approach (Glideslope is inoperative)

Decision Altitude

A Specified altitude (MSL) on an instrument approach procedure (ILS, GLS, vertically guided RNAV) at which the pilot must decide whether to continue the approach or initiate an immediate missed approach if the pilot does not see the required visual references.

Profile view of a non precision approach contains the following items:

Radials or bearings of the IAP to be flown

Fix name and navigational aid (NAVAID) used to conduct the approach

Vertical Descent Angle (VDA), which is information required to establish a stabilized approach descent from the FAF to the TCH

Missed Approach Icons

FAF depicted by a Maltese cross

Visual Descent Point (VDP), where normal descent from the MDA to the runaway touchpoint may be commenced

Procedure turn altitude

Minimum altitude over FAF

FAF

Threshold Crossing Height (TCH) in feet AGL

Distances

Missed Approach Point (MAP)

Missed approach track shown as a dashed line

Which types of information would a precision approach contain?

 Displaced threshold

 Courses of the IAP to be flown

 Missed approach icons

 Navigation frequency

 Minimum procedure turn altitude

Which types of information would a nonprecision approach contain?

 Radials or bearings of the IAP

 Approach NAVAID

 Airport coordinates

 Vertical descent angle

 Missed approach icons

Precision Minimum Section

consist of minimum parameters on certain aspects when landing, like ceiling height, distances, and weather. Numbers often differ according to aircraft category.

Primary data types of the minimums section are:

Aircraft approach categories and variations of the approach procedure

Aircraft approach categories

Determined according to landing speed at maximum certified gross landing weight

Variations of the approach procedure:

Straight-in, Localizer, Circling

Straight-in

to the aligned runwa

Localizer

when the glideslope component is inoperative (nonprecision approach)

Circling

when aircraft must circle to another runway because of wind direction and/or velocity or runway restrictions

MDA

lowest altitude, expressed in feet above MSL, to which descent is authorized on final approach or during circle-to-land maneuvering in execution of an IAP where no electronic glideslope is provided.

Height of MDA above Touchdown zone (HAT)

Used for localizer approach because runway is known

Height of DA above Touchdown zone (HAT)

Used for straight-in approach only because the landing runway is known

Height of MDA above airport (HAA)

• Used for circling version because runway is not known

• MDA for the circling version of the approach is the high

HAT

The height of the Decision Height or MDA above the highest runway elevation in the touchdown zone (first 3,000 feet of the runway). Published on instrument approach charts in conjunction with all straight-in minimums.

HAA

The height of the MDA above the published airport elevation. This is published in conjunction with circling minimums.

RNAV (GPS) Minimums – Approach Procedure Variations:

LPV, LNAV/VNAV: Lateral navigation/ Vertical navigation, LNAV: Lateral Navigation

LPV

Localizer Performance with Vertical Guidance uses Wide Area Augmentation System (WAAS) to attain higher accuracy lateral and vertical guidance

• Requires specific avionics

LNAV/VNAV: Lateral navigation/Vertical navigation

Uses either WAAS or Baro-VNAV to provide vertical guidance

LNAV: Lateral navigation

No vertical guidance provided; does not require WAAS

What types of approach variations are listed in the minimums section of an IAP?

Straight in

Circling

Localizer

For a pilot conducting a nonprecision approach, what is the lowest altitude to which descent is authorized on final approach?

Minimum Descent Altitude

Visual Approach

authorizes a pilot to proceed visually and cleared of clouds to the airport while operating on an IFR flight plan.

In a visual approach the pilot must, at all times, have in sight either the:

• Airport

• Preceding aircraft

In a visual approach the approach must be:

• Authorized

• Under the control of the appropriate ATC facility