RNAV STARs in Clearances
The AIP Canada, RAC 9.2 is all the resource you should need for STARs in general, and RNAV STARs in particular. In fact, most of the information in this section is related to RNAV STARs, since conventional STARs are flyable by anyone, by their very definition.
First things first for RNAV STARs. RNAV STARs are not a requirement for any aircraft or pilot to fly. They exist as a means for an aircraft to navigate from the enroute structure of airspace and airways (or "directs") to the approach phase of flight with a minimum of ATC intervention. In the old days, the primary means of transition from the enroute phase of flight to an approach in a terminal area was by radar vectors from controllers. This is still done where RNAV STARs exist, simply because not all the variables can be controlled to the extent necessary to permit each aircraft capable of flying them to do so without ATC's hand.
There are a number of requirements the aircraft must meet in order to be authorized to fly an RNAV STAR. This is why some aircraft, though they seem equipped for it on the surface, never fly them.
Next, the pilot (or dispatch) is expected to file the RNAV STAR in the flight plan if they desire this procedure. As such, it becomes an integral part of the flight plan route, just as much as over a VOR for an airway, or a preferential routing as published. The pilot will receive his clearance at point of departure, and this will normally include the term "flight plan route" in there somewhere. Since the RNAV STAR is part of the flight plan route, the pilot is expected to fly that unless otherwise cleared. This should eliminate the chance of confusion over which STAR if there is more than one, since the STAR expected by ATC would be the one on the flight plan. The RNAV STAR is not generally restated, since it is part of the flight plan route, but will be restated as necessary if the STAR was cancelled, either explicitly or implicitly, and must be reinstated. If ATC clears an aircraft inbound for a STAR down to a new altitude, the aircraft is still expected to make any speed and altitude restrictions published, and descend to the cleared altitude at appropriate points along the STAR routing. For example, if cleared to 4,000, but the RNAV STAR has a "6,000 or above" restriction at PointA, the pilot may not descend below 6,000 until past PointA unless specifically authorized by ATC to descend earlier, but may continue descent to 4,000 once past PointA.
An RNAV STAR is automatically cancelled when ATC assigns radar vectors or when cleared to a fix that is not within with RNAV STAR. If ATC clears an aircraft directly to a fix within the STAR but it circumvents other fixes (for example, if points A, B, C, D and E are in the STAR, the aircraft is between A and B, and ATC clears the aircraft direct to D), ATC will either state something to the effect of, "balance of the route unchanged," or will state the entire route, fix by fix.
These procedures haven't, to my knowledge, changed in a while, but there were a few revisions to the rules when the RNAV STARs first came out a few years back. There were several meetings involving designers, aircraft operators, and the regulator (Transport Canada) to determine the best wordings for clearances and such, and this is how they stand to date.
First things first for RNAV STARs. RNAV STARs are not a requirement for any aircraft or pilot to fly. They exist as a means for an aircraft to navigate from the enroute structure of airspace and airways (or "directs") to the approach phase of flight with a minimum of ATC intervention. In the old days, the primary means of transition from the enroute phase of flight to an approach in a terminal area was by radar vectors from controllers. This is still done where RNAV STARs exist, simply because not all the variables can be controlled to the extent necessary to permit each aircraft capable of flying them to do so without ATC's hand.
There are a number of requirements the aircraft must meet in order to be authorized to fly an RNAV STAR. This is why some aircraft, though they seem equipped for it on the surface, never fly them.
Next, the pilot (or dispatch) is expected to file the RNAV STAR in the flight plan if they desire this procedure. As such, it becomes an integral part of the flight plan route, just as much as over a VOR for an airway, or a preferential routing as published. The pilot will receive his clearance at point of departure, and this will normally include the term "flight plan route" in there somewhere. Since the RNAV STAR is part of the flight plan route, the pilot is expected to fly that unless otherwise cleared. This should eliminate the chance of confusion over which STAR if there is more than one, since the STAR expected by ATC would be the one on the flight plan. The RNAV STAR is not generally restated, since it is part of the flight plan route, but will be restated as necessary if the STAR was cancelled, either explicitly or implicitly, and must be reinstated. If ATC clears an aircraft inbound for a STAR down to a new altitude, the aircraft is still expected to make any speed and altitude restrictions published, and descend to the cleared altitude at appropriate points along the STAR routing. For example, if cleared to 4,000, but the RNAV STAR has a "6,000 or above" restriction at PointA, the pilot may not descend below 6,000 until past PointA unless specifically authorized by ATC to descend earlier, but may continue descent to 4,000 once past PointA.
An RNAV STAR is automatically cancelled when ATC assigns radar vectors or when cleared to a fix that is not within with RNAV STAR. If ATC clears an aircraft directly to a fix within the STAR but it circumvents other fixes (for example, if points A, B, C, D and E are in the STAR, the aircraft is between A and B, and ATC clears the aircraft direct to D), ATC will either state something to the effect of, "balance of the route unchanged," or will state the entire route, fix by fix.
These procedures haven't, to my knowledge, changed in a while, but there were a few revisions to the rules when the RNAV STARs first came out a few years back. There were several meetings involving designers, aircraft operators, and the regulator (Transport Canada) to determine the best wordings for clearances and such, and this is how they stand to date.
posted by Michael at
06:35
