Talk:Instrument approach

Untitled
Couple of changes:
 * Added Joint Precision Approach and Landing System (JPALS), currently in development for use by all services and possibly select contract carriers.
 * Changed NDB approach to ADF approach (the correct term found on today's approach plates).
 * many countries call them NDB approaches. Added back.BaseTurnComplete 20:26, 7 August 2006 (UTC)


 * Changed SRA (non-existant) to ASR (Airport Surveillance Radar), which provides azimuth and distance out to about 60 miles, but not elevation, hence it's inclusion in the non-precision approach category.
 * ICAO calls them Surveillance Radar Approaches (as per Doc 4444 PANS-ATM). Changed back.BaseTurnComplete 20:26, 7 August 2006 (UTC)


 * Corrected some additional abberant terminology.
 * Much of it added back as it wasn't aberrant. Please sign your comments in discussion with four tildes!BaseTurnComplete 20:26, 7 August 2006 (UTC)

NDB saeria uma antena que emite uma freguencia que é captada pelo ADF da aeronave, indicando assim sua posiçao [da antena]; VOR\ seria o mesmo do ADF porem mais preciço e indicador de distancias.

Precision Approaches Don't Include LPV
GPS+WAAS (LPV) is listed as a precision approach type, but it's not. Some LPV approaches have minima that are the same as those for ILS Category 1 approaches, but LPV can't be theoretically proven to meet ICAO Annex 10 tolerances for a precision approach. Therefore, I'm moving LPV to the Non-precision approach types, despite the functional regularity and precision of the system. --Conortodd (talk) 19:26, 31 May 2010 (UTC)

Added reference to FAA requirements for airports
Most folks focus on the airplane, a few on the flight crew, and most don't think about the need for airports to have an adequate infrastructure to support reduced visibility landings. With new technologies such as GPS, WAAS/LAAS, Head Up Displays, Enhanced Vision (Infrared) and Synthetic Vision (is that real or is it Flight Simulator? :) ) it is technically possible to do a landing under Cat II or even Cat IIIa conditions without having a properly equipted airport - and in fact this is a real concern for those doing design and approval of these new systems.  HOWEVER the pilot should also consider "What happens if I go off the runway and require emergency equipment? or Will I be able to taxi if the taxiway lights are not visible because of this fog?"   All these are addressed by the appropriate airport infrastructure requirements. Brian (ZazenCID 13:59, 1 June 2007 (UTC))

Added References to Head Up Displays
HUDs have been approved for manually flown approaches and landings down to Cat IIIc for some time. HUDs offer a lower cost solution to providing this capability then the traditional fully coupled autoland systems and are gaining increasing popularity for feeder aircraft which typically do not have the required redundancy of flight control systems for autoland. (A computer "glitch" at flare during a CAT III landing which causes a multi-axis hard-over is considered unrecoverable and catastrophic - designing automated systems to prevent that, and then getting approval for those systems, is very expensive. The alternative is to keep the pilot actively flying the aircraft following guidance cues provided by the ILS sensors.  If a sensor provides a guidance cue which suddenly goes hard right, the pilot can act in a more rational manner then just following the cue as an automated system would.)

In addition, aircraft equipped with an approved HUD with Enhanced Vision (infrared camera such as Max-Viz or CMC) are approved to fly a Cat I approach to Cat II minimums. 14 CFR 91.175 (amendment 281) 121.651 (ammendment 303) 125.381 (amendment 45) 135.225 (amendment 93) Brian (ZazenCID 14:18, 1 June 2007 (UTC))

Incorrect Definition of a "Straight In" Approach
The definition given for a straight in approach is actually the definition of a straight in landing. A straight in approach is one that does not involve a procedure turn or hold in lieu of a procedure turn. See the AIM pilot controller glossary. —Preceding unsigned comment added by 192.234.2.90 (talk) 19:23, 7 November 2007 (UTC)

Section on Low visibility approaches [obsolete]
Why does the chart have one side in standard measurements, and the other side in metric? It should be consistant. —Preceding unsigned comment added by 206.116.184.155 (talk) 19:39, 30 March 2008 (UTC)

The ILS Cat chart was poorly done. There are multiple values and the correct value depends on the country. Mathematical conversion of units is not reliable. The ILS Cat chart didn't belong in this article. It is now in the ILS article. You may register the complaint there. 75.247.144.44 (talk) 04:54, 14 March 2013 (UTC)

Contact approach?
Should there not be some mention of the contact approach here? LeadSongDog (talk) 20:41, 23 February 2009 (UTC)

and VISUAL Approach too. —Preceding unsigned comment added by 72.25.92.134 (talk) 21:01, 20 May 2010 (UTC)

Low Visibility Approach definition
ICAO documents (Annexes, PANS and several other relevant docs) contain no explicit definition of low visibility approach or low visibility operation. The nearest I can find is in a note to Para 7.12.1 of ICAO Doc 4444 (PANS-ATM). The para says "7.12.1 Control of aerodrome surface traffic in conditions of low visibility Note.— These procedures apply whenever conditions are such that all or part of the manoeuvring area cannot be visually monitored from the control tower. Additional requirements which apply when category II/III approaches are being conducted are specified in Section 7.12.2." That being the case the sentence deleted is at best unsourced and as far as the ICAO documentation is concerned, incorrect. treesmill (talk) 06:48, 13 July 2010 (UTC)

Visual Approach Section Has Errors and Needs Additional Information
The section on Visual Approaches (most likely added from the "contact approach" suggestion) has and insufficient and incorrect information. A Visual Approach is not a precision instrument approach; it's not even an instrument approach at all, as it is an instrument or IFR procedure.

However, they are "kinda-sorta" instrument approaches because you must be on an IFR flight plan to fly one, so I would suggest renaming the section "Other IFR Approaches" or something, and adding additional "other approaches" such as contact approach, circling approach, side-step, etc.

Also, I suggest moving Circling Approach and Visual Approach, with the suggestions above, to the main section of the article. They are unique Instrument Approach Procedures and not "concepts." Perhaps the "body" should have 3 sections (keeping the intro and basic principles): Precision, Non-Precision, and Other Approaches with information in other parts of the document. I'll try to edit ASAP, unless somebody beats me to it. Captjosh (talk) 20:00, 25 November 2010 (UTC)

Back course approach
Back course approaches shouldn't be listed under concepts but under non-precision approaches, or even better, move the section on back course approaches to the article for localizer (with a redirect from back course approach). A back course would be what I call a variation of a localizer approach, since they're using the same beam that a front-course uses (i.e. you won't ever have a back course without having a front course, but the reverse can not be said to be true). (BTW, I put my opinion on the re-write of this article in the WikiProject discussion). HiFlyChick (talk) 11:12, 12 January 2011 (UTC)

75.247.144.44 (talk) 05:10, 14 March 2013 (UTC)
 * Flying a front course backward is different from flying a localizer back course. A back course doesn't exist for a shielded localizer.  For example, if there is a localizer for runway 18 that radiates a signal both north and south, then that localizer can be used as a back course to land on runway 36 when arriving from the south. This is a very different scenario from arriving from the south, overflying runway 36, and picking up the localizer somewhere north of the runway then following it (the front course backward) to the north (for some time or distance) before returning to land on runway 18 (following the front course forward).

Acronym troubles
This article contains many acronyms. Most seem to be either explained or linked with an outgoing wiki link, with a few exceptions (such as IAS, which is completely unexplained). However, many of the acronyms are explained or linked further into the article than their first appearance. This makes this article very difficult to read for non-experts.

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When changing the language to german an article about decision hight (Entscheidungshöhe) comes up. The correct one might be "Anflugverfahren". Since the german one is much shorter it is always nice being able to read more in the english version which is not possible yet because this site seems to have no other language versions. — Preceding unsigned comment added by 2A02:8109:98C0:3B44:25B3:E554:2861:256F (talk) 23:29, 20 January 2021 (UTC)