Aviation In Canada

Friday, June 03, 2005

Cancellation of a STAR

Back to this topic again. First, let's go back to the one that started it all...

...There is a new procedure in place, I don't know if only in Edmonton FIR or accross Canada, where now, ATCs don't clear you for an arrival if you file the arrival in the flight plan. For instance if you file CYEG J508 Toron.Toron3 arrival CYYC, then the only thing you will hear is clear down to 12000, pilot's discretion. Half of the pilots call back asking if they are cleared for the arrival...

While this sounds like a statement, it was a lead-in for a question. Why will ATC not restate the STAR if they intend for the pilot to fly it? The RNAV STAR section in the AIP is direct about it, but not anywhere near as descriptive about conventional STARs (those that may be flown without RNAV equipment on board). The concept is the same, from what I'm finding out. The STAR is to be filed as part of the flight plan, and to be flown when ATC issues a clearance that either explicitly states it, or issues a clearance that "contains" it, such as, "flight plan route" on the initial departure clearance. Where it gets really murky is when the STAR is canceled while enroute.

If a pilot is removed from his flight plan route, effectively the STAR is canceled until he is put back on it, or some reasonable semblance thereof. The "reasonable semblance" is meant to be interpretted as, "back to a routing which includes the STAR". Example? Aircraft123 is flight planned CYAA V999 ALPHA V888 BRAVO V777 CHARL CHARL4 CYZZ. If ATC vectors him off V999 just before ALPHA intersection, the STAR is canceled, just as the rest of the route is. When you're by the traffic, ATC can offer a new routing, which may or may not reinstate the STAR. Here are some clearance examples and the effects on the STAR:

"... cleared direct BRAVO, flight plan route." -- STAR reinstated, since the pilot is instructed to go direct to BRAVO and rejoin his flight plan route, which contains the STAR.
"... cleared direct CYZZ" -- STAR is canceled, since the new routing issued to the pilot passes the STAR entry point, CHARL.
"... cleared direct CHARL." -- Ambiguous. I'll bet a 50/50 split here for interpretations. My personal opinion is that since CHARL4 was not included, and the term "flight plan route" wasn't either, this is not a complete clearance. What does the pilot do after CHARL? It's not specified. The controller was lacking in direction here, so as much as this clearance shouldn't be issued, the pilot shouldn't accept it, either, at least not without questioning what to do after.
"... cleared direct CHARL, hold as published. Expect further clearance at 1410" -- Also an incomplete clearance, techincally. The pilot has everything for comm failure in the hold but a route to follow after CHARL. The only difference here is that comm failure instructions would allow the pilot to follow the flight plan route since CHARL is on it. If comm is still good, this should be solved by further communications, so this is covered. It would be more descriptive to include, "expect further clearance via CHARL4 arrival at 1410."
"... cleared direct CHARL, CHARL4 arrival" -- Pretty obvious here.

Have I left anything out? I've tried to cover this, but I'm not sure I got every interpretation or situation covered. One thing that I don't appreciate is sometimes an enroute ATC group issues a clearance to an aircraft that does negate the STAR, and even sometimes occasionally forgets to pass this information along. In the above example, one facility may clear the aircraft "direct CYZZ," and not tell the next sector or unit. Though this is happening less frequently, in my experience, than it has in the past, it still occasionally happens. Even if they do tell us they did it, it does leave the pilot without the STAR they initially filed. This is OK if the pilot really doesn't want to fly the STAR and the terminal unit at the destination is OK with that as well. But it does mean that someone is filing a STAR for whatever reason and the STAR is circumvented, perhaps inadvertently.

I'll welcome more comments from anyone about my interpretations, or other situations.