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CAeM e-Forum • View topic - MSC's work on understanding critical wind directions

MSC's work on understanding critical wind directions

Moderator: Stephanie Desbios

MSC's work on understanding critical wind directions

Postby Steve Ricketts » Thu Jun 17, 2010 13:59 GMT

Hi all!

Given that a key goal of our ET is to consider new services in support of terminal operations, I thought I'd share details on an initiative that the MSC has been working on.

We've been discussing ways to focus more of our attention on supporting terminal operations, and the question has come up regarding "what" (we will supply) and "how" (we will measure success); i.e. whether our services have a positive impact, including saving costs for the air carriers (this is a key goal for us).

We could (and already do) measure how well our TAFs perform with respect to forecasting ceiling and visibility, specifically with regards to limits (both those specified in Annex 3 and domestic ones as laid out in our MANAIR document). But a problem is that these limits are not that meaningful to the operations of a major terminal which has equipment to support CAT III operations.

A TAF is a regulatory product that supports the safe operations in and around a terminal. We also need products that support an efficient operation.

So where should we focus energy? Where it matters the most, of course, to the airport authority and air carriers. A couple of years ago, based on a query from NAV CANADA, we conducted a study into the impact of weather, specifically winds, on the terminal operations and also its impact on the Airport Acceptance Rate (AAR)… the number of arrivals per hour. The AAR could be considered as the ultimate measure of terminal efficiency, and it is influenced by airport configuration (runways, equipment), runway conditions (wet, contaminated by snow) and also by meteorological parameters (wind, precipitation, ceiling; e.g. whether the pilots can maintain visual contact).

We presented our work to NAV CANADA and also to one of its working groups (that includes reps from NAV CANADA's operations, the air carriers, and airport authorities). See the two attachments (PowerPoint files).

Based on a better understanding of which winds were important, we felt that we could predict the active runway and even develop an estimate of the AAR in the future (an AARE). People were interested in the work, but weren't ready yet to make it an operational tool. I think the biggest concern was that we were seen -- or could be seen -- as horning in on their territory; i.e. the NAV CANADA operational staff at the Area Control Centres (what the Americans call an ARTCC) felt that determining the AAR is something that THEY do, not us, and having us produce a product visible to end users might be confusing.

Anyway, I think it's really good, useful stuff, and I've been thinking re how to tap it… perhaps not for the AAR/AARE part, but for the critical wind direction info. The results could be used in two ways: to provide guidance to forecasters to help them to focus their efforts, and as a metric of the quality of our efforts. Indirectly, of course. We can, more or less, predict the active runway, but not necessarily the AAR, as its driven by non-weather factors and there's some subjectivity involved (although we can provide guidance on those weather elements that affect it). The metric could be how much notice we give of meteorological factors that change the AAR; whether it's a wind shift that changes the active runway, the start of precipitation that affects its condition. This could be based on the TAF or other products (and advice).

As per the examples in the attached presentations, we could create a graphical display of the TAF, overlay it on the runway configuration, and colour-code it.

This would have two purposes. One would be to show the forecasters the parts of the TAF that are the most important to key on, and to reduce the length of the TAF by focussing on those changes that are truly significant; i.e. the weather elements (wind and precipitation) that will determine the operational (active) runway, and influence the AAR. (I don’t know your forecasters, but ours love to tell a complete meteorological story about how the weather is evolving, but much of the detail is not relevant to the users.) We could reduce the length of TAF by eliminating part periods containing non-significant changes.

See the example of the TAF for Toronto Pearson (CYYZ). The two most critical part periods are between 1200-1500 and 0200-0400 UTC, because that's when the active runway is predicted to change, especially after the runway becomes wet. Many of part periods are for changes in strong southwest winds… but they don't change the active runway.

Also, this graphical display (or a simplified version of it… see the presentation) could be useful to the aviation users… a head's up (high glance value) re how changes in the weather might affect the terminal operations.

Anywhere, that's where we are today. Not sure if other countries have done work along the same line. Comments very welcome!

..steve

CDM_Hub Critical Wind.ppt
(3.03 MiB) Downloaded 508 times

MSCs HUB Focus_CDM09-01c.ppt
(917.5 KiB) Downloaded 466 times
Steve Ricketts
 
Posts: 1
Joined: Fri Mar 19, 2010 03:00 GMT

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