====== 206A - Instrument Approaches ======

Instrument Procedures Handbook Ch 4

===== Instrument Approach Charts (In) =====

Included in TPP publication (28 day cycle)

Current format "pilot briefing" started in 2000.

Approach name at top & bottom of approach plate

Communication Strip - in order of use

Name of the publication plus notes indicate required equipment

GPS may be used to replace VOR, DME, NDB, or compass locator for an approach



===== Chart Supplement and NOTAMs (Re) =====

Airport information lists "Radio Aids to Navigation" -- this will include ILS

===== Approach Minimums - Inoperative Equipment (In) =====

See pg 1 in TPP

===== Approach Briefing Procedures (In) =====

  * Briefed prior to IAF
  * Briefing should include:
    * FA Course
    * Nav Aids
    * Minimums
    * Missed Approach procedures

===== Instrument Approach Checklists and Procedures (In) =====

===== The Approach Clearance =====


Expect to be cleared to a "holding fix" and then recieve "cleared....approach." This removes the expectation to hold. The aircraft is then expected to begin the approach at the cleared holding fix via IAF or feeder route to IAF.

When cleared for the approach, the published feeder routes that lead from the enroute structure to the IAF are part of the approach clearance. (AIM 5-4-6)

"Maintain 2,700 until established, cleared ILS Runway 20 approach."
===== Weather Requirements for Instrument Approaches (In) =====

Part 91 - No requirements to conduct the approach.

600-2 / 800-2 requirements apply for alternate airports

Part 135 -- May not depart if destination forecast is below approach minimums. Weather must be above minimums before starting the instrument approach, and before crossing FAF.

===== Approach Procedures - Visual and Contact Approaches (In) =====

Visual approach -- descend & land VFR. Not a true instrument approach.

Contact Approach -- Must be requested by the pilot, must remain VFR (1SM/CoC), provides IFR seperation

===== Approach Procedures - ASR and PAR (In) =====

AIM 5-4-11 states...
The only airborne radio equipment required for
radar approaches is a functioning radio transmitter
and receiver.

A radar approach may be given to any aircraft
upon request and may be offered to pilots of aircraft
in distress or to expedite traffic, however, an ASR
might  not  be  approved  unless  there  is  an  ATC
operational  requirement,  or  in  an  unusual  or
emergency situation.

PAR  and  ASR  minimums  are  published  on
separate  pages  in  the  FAA  Terminal  Procedures
Publication (TPP).

For our area, ASR approaches are available at BLV, CMI, and SPI. 

A PAR approach is available at STJ (St. Josephs, MO) which is an ANG base, class D.

==== PAR - Precision Approach Radar ====


Both lateral and vertical guidance. Pilots are told when to turn to maintain alignment on the landing runway and when to begin a descent to maintain the glidepath required. Pilots will be advised to fly the missed approach, if needed.

==== ASR - Surveillance Approach ====


Less accurate radar used, no vertical guidance. Flown like a non-precision approach. Pilots are advised to descent to MDA or stepdown altitude by ATC. Pilots are advised to execute a missed approach at the MAP if needed.


===== Approach Procedures - VOR (In) =====

See [[https://skyvector.com/files/tpp/1905/pdf/06351VDA.PDF|VOR-A Approach Sample]]

[[https://skyvector.com/files/tpp/1905/pdf/09119V24.PDF|PNT VOR 24]]
===== Procedure Turn (In) =====

Used to establish the aircraft inbound on the final approach course

Barb symbol indicates pilot may use any method of PT to include:

  * 45 deg method
  * 80/260
  * Teardrop
  * Racetrack

If a specific PT is depicted, the pilot MUST fly this procedure.

<note tip>If the aircraft is cleared for a straight in approach, the PT is not to be flown.</note>

See ILS 20 MWA and [[https://skyvector.com/files/tpp/1810/pdf/00232IL18.PDF|ILS 18 LNK]]

Exceptions will be noted as "No PT" on the approach plate -- [[https://skyvector.com/files/tpp/1810/pdf/00235VA.PDF|VOR-A (LNR)]]

<note tip>FAR 91.175j states... In the case of a radar vector to a final approach course or fix, a timed approach from a holding fix, or an approach for which the procedure specifies "No PT," no pilot may make a procedure turn unless cleared to do so by ATC.</note>

===== Radar Vectoring (In) =====

Pilots may be vectored to the IAF or onto the final approach course

<note tip>When not in radar coverage, a pilot MUST report the FAF inbound.</note>

===== Approach Procedures - Circling Approaches (In) =====

Approach not lined up with runway

Land on another runway

Safety area based on approach category

|Category|Radius|
|A|1.3|
|B|1.5|
|C|1.7|
|D|2.3|
|E|4.5|

Only circling minimums published if...

  * Final approach course more than 30 degrees off runway heading
  * Decent greater than 400ft/NM from FAF to TCH
  * Runway not clearly defined on the airfield

Circling minimums provide 300ft of obstacle clearance within the radius above (AIM 5-4-5 e 2).
===== Landing from an Instrument Approach (In) =====

FAR 91.175c governs operations below DA or MDA...

To descend below DA or MDA, you must have one or more of the following in sight:

  * The approach light system*
  * The threshold.
  * The threshold markings.
  * The threshold lights.
  * The runway end identifier lights.
  * The visual approach slope indicator.
  * The touchdown zone or touchdown zone markings.
  * The touchdown zone lights.
  * The runway or runway markings.
  * The runway lights.

<note tip>If only the approach light system is in sight, the pilot may not descend below 100 feet above the touchdown zone elevation using the approach lights as a reference unless the red terminating bars or the red side row bars are also distinctly visible and identifiable.</note>
===== Approach Procedures - Missed Approach Procedures (In) =====

Graphical and narrative on approach plates

When to initiate:

  * ILS/LPV -- at DA
  * Non Prec -- at MDA + Time or Distance

===== DME Arcs - Intercepting and Tracking (In) =====

[[https://skyvector.com/files/tpp/1810/pdf/00628VD22.PDF|PAH VOR/DME 22]]

===== ILS Critical Areas (In) =====

Taxiway boundary sign + painting

===== ILS Principles of Operation (In) =====

Localizer
  * 700ft wide at the runway threshold.
  * I-XXX identifier
  * Frequency is tuned on NAV radio
  * 18mi range within 10 degrees (10mi within 35 degrees)

Glideslope
  * Operates on UHF frequency paired to localizer frequency
  * Antenna on side of runway (250-650ft away, 750-1250ft from threshold)
  * 1.4 degrees wide (vertically)
  * Standard is 3deg GS
  * Normally usable to 10NM
  * Normal intercept 1400ft AGL at OM
  * 

===== Approach Procedures - ILS (In) =====

MDH ILS 18L

===== Approach Procedures - Localizer (In) =====

[[https://skyvector.com/files/tpp/1810/pdf/06547LD21.PDF|FOA LOC/DME 21]]

===== Approach Procedures - LDA, SDF, and MLS (In) =====

LDA - Localizer Directional Aid

SDF - Simplified Direction Finder

MLS - Microwave Landing System

===== GPS Substitution =====


[[https://blog.aopa.org/aopa/tag/ils/|When to Switch to Green Needles]]