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If you are not aware, London Gatwick (aka EGKK) has a setup with a primary air carrier runway and a backup runway immediately next to it, such that only one runway can be used at a time.

The main runway 8R/26L (South) has full HIALS (ALSF-2 in FAA parlance) with CAT III ILS as well as RNAV (LNAV/VNAV, no SBAS/LPV) and plated SRA non-precision approaches; however, the backup runway 8L/26R (North) only has RNAV and SRA approaches, and no ALS.

Similar runway configurations in the US (KEWR aka Newark Int'l is similar save for having a crosswind runway) allow what is called a sidestep ILS procedure, where the main ILS is flown to higher (nonprecision) minima and then a maneuver is executed on short final to "slide" over to the other runway after visual contact with both runways has been achieved. From AIM 5-4-19:

5−4−19. Side−step Maneuver

a. ATC may authorize a standard instrument approach procedure which serves either one of parallel runways that are separated by 1,200 feet or less followed by a straight−in landing on the adjacent runway.

b. Aircraft that will execute a side−step maneuver will be cleared for a specified approach procedure and landing on the adjacent parallel runway. Example, “cleared ILS runway 7 left approach, side−step to runway 7 right.” Pilots are expected to commence the side−step maneuver as soon as possible after the runway or runway environment is in sight. Compliance with minimum altitudes associated with stepdown fixes is expected even after the side−step maneuver is initiated. NOTE− Side−step minima are flown to a Minimum Descent Altitude (MDA) regardless of the approach authorized.

c. Landing minimums to the adjacent runway will be based on nonprecision criteria and therefore higher than the precision minimums to the primary runway, but will normally be lower than the published circling minimums.

Why has the UK not published similar minima for Gatwick's ILS? The existing OCHs for the secondary runway RNAV approaches are in the 650' range -- if the Newark ILS sidestep minima are any indication, it'd be possible to obtain lower minima for a sidestep approach to the EGKK secondary runway than are currently available from the RNAV or SRA approaches, and it would require no new navaids to be put into service.

Are sidestep approaches verboten in JAR-land? Is there some terrain or obstacle factor that I'm not seeing that makes a sidestep ILS approach into EGKK problematic or not desirable relative to the current RNAV approaches to the secondary runway? Or can the ICAO/CAA format for approach plates not represent sidestep minima?

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    $\begingroup$ I think the core part of your question is, "Are sidestep approaches verboten in JAR-land?". The only online references seem to be for the US, so rather than focusing the question on one airport, you might want to ask the simpler question first of whether they even exist in the UK (or outside the US, or under EASA, or however you prefer to phrase it). $\endgroup$ – Pondlife Mar 3 '16 at 19:52
  • $\begingroup$ @mins -- there are RNAV approaches published for it as well $\endgroup$ – UnrecognizedFallingObject Mar 4 '16 at 0:50
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You use circling minima for sidestep manoeuvres. While not commonly practiced, they may be requested by the pilot, have done so many times when LEMD (MAD) is in N config, saves 20min taxi-time...

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After a lot of Googling, it looks to me like a side-step ILS approach is exclusively a US term and - at least practically speaking - it doesn't exist in the rest of the world. There are almost no relevant search hits for the term in other countries; Transport Canada includes it in their glossary but it's a direct copy from the FAA's P/CG and is noted as a US term:

U.S.: A visual maneuver [sic] accomplished by a pilot at the completion of an instrument approach to permit a straight-in landing on a parallel runway not more than 1200 ft to either side of the runway to which the instrument approach was conducted.

I did find out that some other countries use the term swingover for more or less the same thing, but the only two extensive sources I found are in German: IVAO Deutschland and wikipedia.de. Neither of them quotes a regulatory or ICAO source. The IVAO page says that pilots usually ask for a swingover, whereas in the US - at least based on what I found in forums - ATC will request it from the pilot.

But even if you're willing to accept that "it's a US thing", it doesn't explain why only the US has side-step approaches. I can think of a fairly vague reason, but I may be completely wrong. Side-step minima are different, as the ATC orders (section 4-8-7) note:

Side-step maneuvers require higher weather minima/MDA. These higher minima/MDA are published on the instrument approach charts

That means it takes actual work to create side-step minima, you can't just use them 'for free' from another ILS approach. So my guess here is that the US simply has - or, historically, had - better ILS and weather reporting facilities than many other countries do, as well as more resources directed at defining approaches and more flights going into busy airports. In other words, side-step approaches are more practical, 'affordable' and useful for the US than for other countries. But that's entirely my own speculation, and if someone can find a documented reason that would be great.

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