Aviation In Canada

Thursday, June 30, 2005

Flight Following Anyone? Part 1

In October of 2002, I was working the sector which covers southwestern New Brunswick in the evening hours, just ahead of dusk. A PA-28 Cherokee had departed Fredericton, NB (CYFC), VFR enroute to Halifax, NS (CYHZ). Cruising at 5,500, he decided to call for flight following and was radar identified. About half an hour or so after departure, the flight was approaching Greenwood MTCA's airspace, and under normal circumstances I would have handed a flight on his track to Greenwood, since at his altitude on the frequency I was using, communications are often sketchy but Greenwood would be able to work him no problem. I'm still not sure why I didn't.

In the middle of a steady, but not really busy, flow of traffic, I heard through a readback of a clearance on a different frequency one of my aircraft, "declaring an emergency." I managed to pick out who it was but not the nature.

November Bravo Oscar, I heard you're declaring an emergency, but I didn't catch the nature of it.

This is something that I always love. Not the emergency, mind you. Every other pilot on all the frequencies I was working went instantly quiet. No more requests for direct this place, reporting of light chop or anything else. They were smart enough to know that someone was in trouble, and give me a clear and open frequency to hear him. Even though they may not know what frequency this pilot is on and may not hear him themselves, they still know to keep quiet so we can communicate.

The response indicated the seriousness of the situation. The pilot said his engine had failed and he needed a vector to the nearest airport. Most of the fields in the region are private grass or gravel strips, unsuitable for many aircraft types, especially the regular IFR aircraft in the region. As such, they were not indicated on our radar displays. I belted out quickly about Waterville (20 NM south) and Greenwood (22 NM southwest), but knew he wasn't likely to glide 20 NM from his current altitude of 5,300 feet. I knew there was another one nearby and scrambled to find the position of it. Apple River. CCA7.

November Bravo Oscar, there is a small grass strip called Apple River about 5 miles northeast of you, standby for more details...

(more tomorrow...)

Wednesday, June 29, 2005

OMNI Separation

This topic is an interesting one, and is widely regarded as an elegant method of getting an outbound aircraft through an inbound aircraft in a non-radar environment without actually putting them through one another. There are uses as well that go beyond opposite direction aircraft. I'll try to explain a little bit.

The basics are the radials. I'll assume a certain level of knowledge of VORs when I write this, so please feel free if you want me to explain this part a little more.

The radials have to be 15° apart, and not necessarily even numbers like the 010R and the 025R. It's often more convenient, since an aircraft is normally tracking an airway or proceeding directly to a VOR anyway, to start with a radial that is already in use. In the Moncton FIR, the most common place we use OMNI separation is at CYGR, Les Iles de la Madeleine. The airway most commonly used there is V382, which is the 332R. So with an aircraft inbound from Gaspe (CYGP), we would generally make sure he is on the 332R and get a departure out either west of him (this would be 15° west, meaning no higher than the 317R), or east of him (clockwise, higher than the 347R).

It's obvious that there has to be at least one other condition when you think about this. Since the radials actually converge at the facility, having two aircraft established on different radials at 2 DME isn't going to give you much separation. That condition is actually 15 NM. If the two aircraft are established on their respective radials and will pass outside of 15NM from the VOR facility, then you have established OMNI separation, a form of lateral separation. This is, of course, only useable for opposite direction aircraft in this sense. Thus, a vertical restriction is specified to ensure that the aircraft will pass outside of 15NM before discontinuing vertical separation. For those who have flown this and remember hearing a different number, ATC uses different values depending on altitude if using DME to prove the 15NM. Most commonly, OMNI is used at lower levels, and therefore 17DME is the value most commonly referred to.

For example, the inbound aircraft is on V382 (the YGR 332R) from CYGP, while someone wants to depart and head to CYGP also on V382. The inbound aircraft is at 11,000, but wants descent. The outbound aircraft wants to climb to 14,000. The clearance for the outbound aircraft would read something like, "... maintain 14,000. Make climb from 4,000 to 12,000 established on the YGR 315R, not above 4,000 til 17 DME." The aircraft is cleared up to his flight planned altitude, simply because we can. His restriction for the radial climb means that he can't climb above 4,000 until he's established outbound on the 315R (which, incidentally, was chosen as a nice round number that gives at least 15° separation) and that he may not leave the 315R until he reaches 12,000, which is 1,000 feet above the inbound's current altitude. As the inbound aircraft descends, we can ask him for altitude reports; as he leaves 8,000, for example, we can let the departure go off the 315R and on course out of 9,000. This holds our established lateral separation until vertical is proven. As for the DME restriction, the outbound aircraft may not climb above 4,000 until he's on the radial AND outside 17 DME. This restriction is on there in case the outbound aircraft is slower than expected in getting away, allowing us to keep our vertical separation since the lateral provided by OMNI doesn't exist inside the 17 DME mark. Once our departure is airborne, we look at the position of the inbound (well, we ask for a position report) and determine if they will pass outside of 17 DME. If yes, then we can break the 17 DME restriction right off the top and allow the departure to climb, since OMNI lateral will be provided at the point where they pass. Once altitude reports indicate they have passed vertically and are separation by 1,000 feet, we can now cancel the radial restrictions on both, clearing the departure on course and, perhaps, clearing the inbound for an approach.

There are other cases where OMNI can be useful, such as when two departing aircraft are heading in almost the same direction. We can use 30° between them under certain circumstances, but this rarely seems to be a useful application, since other forms of separation are easier to set up and prove. OMNI can also be useful for two inbound aircraft when, for instance, the further is faster and you want to let him overtake the closer one. This is a bit tougher with today's aircraft and their normal speeds, though, as not only does the 17 DME apply again, but there is an additional condition: The second aircraft has to be at least 10 minutes from the facility by the time vertical is established. A restriction would be issued including a time to make good an altitude, giving the opportunity to let the pilot figure out if he can make such a restriction.

Anyway, there are the basics. OMNI is your friend, provided you get to know it.

Tuesday, June 28, 2005

Strip Marking Example, Part 4

Finally, our hero in the PA31 gets his turn at the approach at CYFC. You can see by the strip below tht the pilot reported entering the hold at 2254z, and at some point after that, the preceeding traffic has landed and it's his turn. The controller issues the approach clearance:

Alpha Romeo Tango is cleared to the Fredericton Airport for the VOR Runway two seven Approach. Contact Fredericton Radio now on one one niner decimal zero.

And here is the strip as it appears after the approach clearance is issued:

The two things that mark an approach clearance are the big descent arrow in the center box, and the "Big 'A'" in the box on the right. The "O27" stands for the VOR runway 27 approach (Again, O for Omni). to denote the specific approach the aircraft received clearance for. The others we have would be "I" for ILS, "N" for NDB, "L" for Localizer only, "BC" for Localizer Back Course, "R" for RNAV, "G" for GPS Overlay, "V" for Visual, and "K" for Kontact. I don't know the background reason for a K instead of a C for a contact approach. If the aircraft is cleared for an unspecified approach (Alpha Romeo Tango is cleared to the Fredericton Airport for an approach), then the "Big A" is written on the strip, with nothing specified after, just as in the actual clearance. You can also see that in the small boxes between the altitude box and the information box (where the approach was written), that we have ruled out the holding instructions and written in the frequency to indicate to us that we are still responsible for the aircraft, but no longer in comminucation with him.

Eventually, FART lands and we simply write the time in the boxes on the left. Normally, we only write two-digit times, but if the time is a different hour from the estimate written in the far left, then all four digits have to go in, as seen below:

And this brings this little segment to a close. Any questions? Anything else you'd like to see that I might be able to demonstrate?

One thing you may have noticed about the flight strips: We don't carry information about your alternate airport. In Canada, our strips don't show us that. The requirement for an alternate remains a regulatory one, so it's still required, but we won't know where you want to go if you did a missed approach and simply said, "I'd like to go to my alternate now." I'd still be asking you where and how high.

Monday, June 27, 2005

Strip Marking Example, Part 3

As our Navajo gets further from Saint John (YSJ), eventually he gets to the point where he is considered to be geographically separated from that area, meaning we don't have to consider him traffic over YSJ any more. At that point, the CYSJ departure strip can be removed from the board, and in his case, we only have one more strip, the arrival at CYFC. The controller issues landing information to the pilot (which includes ceiling, visibility, altimeter, runway and approach in use -- which happens to be runway 27 and the VOR RWY 27 approach -- and so on). Due to other traffic at CYFC, the controller has to give our intrepid hero a hold. The clearance sounds like this:

Alpha Romeo Tango is cleared to the Fredericton VOR via V310, maintain four thousand, hold east inbound on the zero nine three radial, expect approach clearance at two three zero five. Report entering the hold.

The strip is marked as follows:

The holding instructions are shown in the little boxes to the right of the center box, as is the EAC time. The little "O" in the big bos to the right indicates the clearance limit, O standing for "OMNI", a carry over from the old days. In the collection of little boxes to the left of the center box, you may have noticed a little check mark. This shows that the controller asked for the report of entering the hold. The time the pilot enters the hold will be marked in there, whether the controller asked for that report or not.

Sunday, June 26, 2005

Strip Marking Example, Part 2

Back to our little miniseries, the controller gets the call that the aircraft has taken off at a time of 2234z. This is marked on the departure strip as shown below:

The with new information to write on one strip, there is often information to be carried forward to the next one, and further, if required. In this case, there is only one other strip for this flight, the CYFC arrival strip. The only information to carry forward is the estimate, so about 20 minutes is added to the departure time to get the aircraft to CYFC, and the time is then passed to FC FSS. As our current procedures in Moncton dictate, we use a red pen to show that this estimate has been passed via phone line to Fredericton Radio. The arrival strip now looks like this:

Eventually, the aircraft calls in to the Center. He is radar identified, and climbs on course as the clearance indicates. For the sake of example, he gets up to about 5,500 and gets into icing, so he requests 4,000 as a final altitude where he wasn't in icing on the climb out. If he had reached 6,000, we would have placed a small check mark next to the "60" on the departure strip to show that he had completed the climb, and all useable altitudes below are vacated. The strips are now marked with the new altitude assignment of 4,000 feet, as shown below:

Eventually, when the aircraft levels at 4,000, a check mark will be placed on the strip next to the new assigned altitude. Procedures in Canada still require a pilot to report reaching an assigned altitude. In a "procedural", or non-radar, environment, this is much more critical. In a radar environment, this is rather unnecessary if their is a lot of radio traffic. How do you know the difference? If you've been told you're, "radar identified," you're in a radar environment until you hear the term, "radar service terminated."

More coming up in future posts, so stay tuned...

Saturday, June 25, 2005

Questions Answered

Before I continue the series, I'd like to try to answer the questions posted in response to yesterday's commencement of the Strip Writing Example. This is exactly what I'm hoping to do, is to spark some "conversation", at least as much as this format will allow.

Question one dealt with why the clearance limit was specified as the YFC VOR rather than the airport. First off, Canadian ATC actually has direction in our MANOPS which allows us to use a NAVAID rather than the airport if the destination is within our FIR. The airport should be used if it is outside the FIR. The reason? We pay attention to NOTAMs regarding facilities in our FIR, but not necessarily those outside it. For example, we'll usually know if the Gaspe VOR is unserviceable, since it's a facility adjacent to our FIR and it could affect the separation used on a route commonly flown between Moncton and Montreal FIRs. However, we don't know the status of the YYZ VOR, since it won't affect our operation. What would a pilot do in the case of a comm failure with the example clearance? Essentially the same as he would have done with the airport as the clearance limit. Comm failure rules, in Canada, allow the pilot to proceed to the clearance limit, and then to a fix from which an approach can be carried out. The time at which he is to leave the facility are specified in the AIP Canada under com failure rules, and include the latest of a number of items, including ETE in the flight plan, last estimate notified to ATC and acknowledged, etc. If I had my AIP, I could tell you properly, but it has temporarily gone missing. In any case, if ATC suspects a comm failure (sees a 7600 squawk, can't raise the pilot on radio, etc), rest assured that we'll be watching for you to figure out what you're doing.

Next, the runway assignment by an IFR ATC unit at an uncontrolled airport is a bit complicated. The pilot has to know the airspace around the airport. For example, at CYSJ, controlled airspace extends to the surface since it's in a Class E control zone. At CYCH, controlled airspace doesn't begin until 2,200 above ground. The difference is subtle. ATC can't issue taxi instructions, nor can they issue a take-off clearance, or for that matter, prevent an IFR aircraft from taking off. ATC can, however, in the case of CYSJ issue IFR clearances and restrictions that dictate when the IFR clearance is valid (and therefore when an IFR aircraft may legally take-off), and what directions he must comply with in the process. That means I can tell an IFR aircraft to depart a particular runway, but the pilot remains responsible to determine if he can depart the runway specified in the clearance, and at the time frame specified. If he is unable to do so (because of rules, traffic, weather, etc), he can certainly refuse the issued clearance and ask for something else. Since we may assign such conditions, we can narrow down what airspace we protect for the departure by assigning conditions as discussed. If such conditions are not specified, we must block more airspace to cover unexpected manoeuvers, such as a change of runway for departure if it is not specified in the clearance. In the case of CYCH, an uncontrolled airport below the base of controlled airspace, we don't have the authority to dictate such conditions, though we can specify times as to when the IFR clearance is valid.

The third question brought forward is a little more complex. As mentioned earlier, at airports that are below controlled airspace, we cannot specify departure instructions such as runway or turn after take-off. As for the obstacle clearance, the pilot is ultimately responsible for manoeuvers until reaching a published IFR altitude for the area regardless of whether the airport is in controlled or uncontrolled airspace. What is known is that for each aerodrome with a published instrument procedure, there is an aerodrome diagram which contains departure minima (visibility) and, where required, any departure procedures such as "climb gradient of 300 feet per NM is required to 1,900 before commencing turns" or any other such information. Basically, if the runway is assessed for obstacles on departure, a pilot can count on meeting obstruction clearance if he follows a few basic rules:

1. Cross the departure threshold at least 35 feet above the threshold elevation,
2. Climbs to at least 400 feet AGL before commencement of any turns, and
3. Maintain a climb gradient of at least 200 feet per nautical mile from there up to the published minimum IFR altitude (a sector altitude from an approach plate, an MEA for an airway if within the airway confines, etc).

This would be a standard departure procedure (not to be confused with a SID, or Standard Instrument Departure). In any case where the above conditions cannot meet obstacle clearance, the departure procedure will have notes and special instructions accompanying the airport diagram that detail any extra requirements either for the airport or for specific runways.

For more information on the last question, I wrote a much more detailed page on this very subject in a miniseries devoted to IFR flight and charts in my past "weekly topics" endeavor. Follow this link to find some examples and interpretations of IFR charts for departures. And remember, everything I have said here applies to Canadian airspace. Each country has their own way of assessing airports and publishing documents, so each country's regulations should be verified in their respective documents.

IFR Flight Part 2a: Departure Procedures

Friday, June 24, 2005

Strip Marking Example

Here's the strip marking example I've been telling you I'd get to. I had an example flight plan made up on a Piper PA-31 Navajo going from Saint John, NB, to Fredericton, NB, filed at 6,000 feet along the airway V310, which surrounds the infamous CYR724 restricted area. I'll narate a little as we go.

In the first two images presented below, the strips have just come out of the printer, and the controller identifies the strips as the CYSJ departure strip and puts a slash in the middle boxes, and the CYFC strip as the arrival strip, and marks a cross there. The flight is proposed off at 2230z and is a westbound flight, so the strips are printed up with the identification info on the left and the fix posting on the right.

At 2229, SJ FSS calls and says "Alpha Romeo Tango is taxiing, requesting IFR clearance off runway 32." The controller slots the strips under the board, checks for possible conflicts, and issues the following clearance to be read to the airplane verbatim:

ATC clears Foxtrot Alpha Romeo Tango to the Fredericton VOR via Victor three one zero, maintain six thousand. Depart runway 32, turn right heading zero two zero to intercept Victor three one zero and proceed on course. Squawk four three two seven. Clearance cancelled if not airborne by two two three five.

The readback from FSS comes and is correct, and now the clock starts ticking. The pilot has to be airborne before 2235z (meaning 2235:01 is too late). The clearance has to be issued by radio, read back by the pilot, the airplane taxied onto the runway and departed by that time. Sound like a tight window? Maybe it is, but that's what the controller could offer. If the pilot can't make that easily, it's always the pilot's discretion to refuse the clearance and wait for a better time. Anyway, the strips now look like this when the clearance is issued:

The altitude is marked in the middle box, showing in hundreds of feet. Just to the right of that, a big "D" is marked indicating a clearance has been "delivered" (with a non-standard notation of time, 30 minutes past the hour). The runway number and departure instructions are written in a standard shorthand, with the "CC" indicating the "clearance cancelled" time. Note how little is written on the arrival strip? That fills up as we approach destination.

More to follow tomorrow... (don't you just hate when people do this?)

Thursday, June 23, 2005

Databoard (for real!)

Ok, here it is. I had to go to our simulator to avoid bothering the controllers on the floor. I took this picture of our basic databoard from low level as it would appear on our "midnight configuration" (except without any live flight plans). This is the term we use to describe how the sectors are configured, or consolidated, over the night shift in Moncton low level. As the daytime traffic dwindles, the various chunks of airspace we call sectors are slowly combined into larger chunks. The frequencies we use remain active, and each controller who receives the new airspaces also receives the responsibility for control, and the associated frequencies (and hotlines to other ATC units). As such, the databoard of the sector being combined is also "folded in" to the master sector. Ultimately, the traffic on the midnight shift in our small FIR (on low level only, high level remains split to some degree throughout the night) slows down to the point where one or two people can manage it, and it is all worked from the same workstation. This controller will end up with 19 frequencies and 16 hotlines all on his one communications panel (the simulator's panel and overall configuration differs somewhat, but the black panel in the lower right hand corner is like one of the comm panels we use).

You'll see in the picture the various fixes we post on our databoard, and they are all determined largely by the significant geographical points and by where we see the most common points of conflict in our routine traffic patterns. The real trick is to spot the ones that are not routine, since a cross of a common track and an uncommon track may not be shown under one of our headers. This is where the mental picture of the traffic, drawn by the placing of strips in the board, comes into play. For example, if an aircraft were to fly from CYYT to CYUL through our FIR, he might fly a routing of YYT J575 YQY J509 HUL and onwards, meaning he would end up being posted under YQY, YQM, YFC and HUL headers. This allows us to clearly picture where he is going, and also to examine other strips posted under these headers to see if there are any potential conflicts. Altitude is generally checked first. Two airplanes at the same altitude? Then look at routes. Common portion, or crossing portion? Look at the estimates (times) for the fix(es). Is there likely to be enough time or distance between them? No? Then control action may be necessary to separate the airplanes.

Anyway, here's the picture of the overview of the databoard. To the left hand side, off the image, would be the radar screen, and under the strip bays from left to right are the hotline buttons, then the printer, the little slots for filing strips that we're done with, and then the comm panel (this one would be used for the data position).

And here's a closeup of the YFC and YSJ headers so you can see some of the items of info we have on them. There are commonly used radials for reference (well, with more and more aircraft capable of RNAV direct, this information isn't referred to as often), as well as distances and frequencies for adjacent units and sectors, and phone lines and numbers for contact. The info on these strips, I notice now, is a little outdated in some cases, but it's enough to give you an idea. I guess I should mention this to someone before the next low level course starts...

Wednesday, June 22, 2005


I have to apologize to all those who have been waiting patiently for more on the flight strips. I can't seem to find the pictures I've taken in the past of the databoard arrangement, and haven't had the opportunity to get a new one for posting here. I promise I'll get to it soon. I did take an opportunity to fake a flight plan of the sort that we might see in ATC and get some strips printed out, so I'll do up a progression that we, as ATC, might see on flight strips, and how we might mark them, with those. Turns out, that'll take a little more effort to do it justice than I thought it would, if you want to see some of the details we see when we work.

So hold on. I'll get some good stuff posted here for you eventually. Maybe a real post, too, that doesn't just apologize for doing a lousy job lately. :)

Tuesday, June 21, 2005

Air Canada Boeings (Not!)

While I prepare the strips for doing my example of stripmarking and the progression (due to the scanning and writing, this will take a little time to put together and I'm in the middle of a work week, so my time is limited), I thought I'd make a brief comment for those who don't already know about the Air Canada/Boeing deal. It's dead. The union rejected the proposal, and the order, sadly, has died. According to one comment from my earlier post about this, the Globe and Mail quoted some union member as saying, "The goal is to redress and correct the inequities of the past four years. Vote No so we can rectify this travesty."

The comment posted asked me, while seeming impatient and a bit angry with the union and their tactic, "How did scuttling the Boeing deal help their cause?" I can't offer an answer to this. Here is what I can say. Remember that we don't have all the information. We don't know even one side of the story, let alone both sides. People don't do things that are out and out stupid without reasons. Heck, even a serial killer does what he does because he thinks its right. It's not until you listen to his reasons until you see why he is doing it. It doesn't make it right, but at least you can understand. Same thing here: Maybe there is something gained on their side with the company. I can't see what it could possibly be, but that doesn't mean there wasn't something achieved. The newspaper doesn't do investigative reporting, they just report the basic fact: "The union killed the deal."

Personally, I don't think unions have outlived their usefulness at all. For many, the union is the only defence the workers have when their employer tries to stir up crap. Unfortunately, too many companies do try to pull stuff they shouldn't do, and even have no right to do based on contracts. If left alone, these individuals would have to fight on their own, and court costs alone would make it beyond the reach of many people. With a union, the group can fight principles in court once, and protect its members that way. Just the fact that a union is looking over the employer's shoulder will often keep managers from doing things to employees they know are wrong. And what of collective bargaining? Without a group to represent the workers, I think you'd see an awful lot of people taking baths on wages and rights without an organization capable of doing something about it. Not that I like strike votes and picket lines and all the incomplete media coverage spreading misinformation and such. I hate it as much as the next guy. But if you can prove to me that this whole process can work amicably without it, then maybe I'll relax my viewpoint a bit. It has taken me 13 years to come around to how I think now, since the inconvenience of having to deal with a group that goes on strike has hit me on more than one occasion, but at the same time, if you read into the issues beyond the headlines, ask some of the individuals involved, you can often see a whole other side to the fight. Try it sometime.

Monday, June 20, 2005

IFR Unit Division

I'm sorry I didn't find my data board picture, but until I can get one to post, I'll give a little detail about the division of Moncton FIR's airspace for some background on how we work. Without this info, the databoard picture would mean less, anyway.

Every center in Canada has "specialties" within it. These are groups of people who work one or more sectors who tend to do similar tasks frequently, so they don't have to learn too many skill sets. This allows them to be better at what they do regularly. For example, in Moncton, we have Halifax Terminal, which deals with a relatively high volume of traffic and a complex mix of aircraft types in a crossing runway environment. Then we have our high level airspace, which feeds Gander for eastbound oceanic traffic, and receives them from Gander for the westbound flow and feeds them to Boston. This daily flow of traffic one way and then the other involves upwards of 350 aircraft all trying to be in the best spot of the jetstream (or out of it on the westbound leg) within a few hours. This takes a good eye to spot conflicts well in advance, and a number of special procedures and techniques not useable outside this area. Then there's low level which takes up everything else.

While terminal does the fast-paced sequencing and departures, they run more aircraft closer together than anyone else in the CTR. High level handles a shear volume of aircraft all in the high level, Class A airspace. Low level, the catch-all for the remainder, deals with the lowest overall traffic volume, but has the highest complexity for operations and background knowledge required. You don't, for example, see many pilots of 747's and A340's having navigation difficulty, where down low, we see all kinds of pilots from high-timers to "new releases" in all different types of aircraft. Also, our high-level specialty doesn't get involved in arrival vs. departure situations, and their airspace is, by necessity, largely radar-covered and all of their area is controlled airspace. Terminal also is all-radar, and their knowledge base need not be very large to contain the primary airports they deal with. With low level's airspace capped at FL280, we have to know low level airspace and airways, along with high level airspace and airways, and deal with uncontrolled airspace (if a pilot understands the nuances of it, it's pretty easy; it's those that don't that require a lot of attention), as well as at least a basic knowledge about a number of airport situations, frequencies, and so on.

This is what leads to specialization within the job. A certain set of knowledge or skills is required day-in and day-out, and the practice level must be good to deal with the specific sets of circumstances regularly. Traffic flow and geography make a big difference in where internal airspace boundaries are drawn and who works what areas and what traffic. Each specialty may have several sectors as well, and each group's area is divided as traffic dictates the need for. If you look at Moncton ACC's area, the high and low level airspace is very differently divided from one another, all because of where the majority of traffic operates within it. I'll try to find an image of our sectorization that I can post here, too, for information sake.

Sunday, June 19, 2005

Flight Progress Strips

As a follow up to yesterday's article, I have taken the time to scan a couple of flight progress strips we use in Moncton ACC. I'll show you the grpahics, and then talk about them a little. For those who are familiar with these in general, they'll look a little different from the strips used elsewhere in Canada, since this one was produced by CAATS, our new computer system that is still undergoing testing in Moncton ACC. Let me apologize for the image posting bleeding into the next column. If I made the imade any smaller, I found I was losing intelligibility, and I had difficulty modifying the blog's template due to the background images. We'll just have to suffer a little here.

Here we see the basic enroute strip. This is a westbound flight, and therefore the basic details are printed on the left-hand side. Starting there, we see the aircraft identification (Canjet flight 161), a Medium wake turbulence category Boeing 737-500, the "W" denotes RVSM certification, filed true airspeed of 428 knots. Underneath that is the SSR code assigned to the airplane. Along the bottom row, we see that he departed St. John's, NF (CYYT), and is proceeding from YYT directly to YHZ, with the destination in the far right bottom corner of Halifax International, NS (CYHZ). The "WL16" is formatting code used by CAATS and is not worth explaining. In the box on the far right hand side is the fix posting, ie where we will post this strip in our data board. This strip is meant to posted under our YQY header strip, but since the aircraft isn't actually going over YQY, we post A/YQY, or abeam Sydney VOR, which means near it. Since the fix posting is A/YQY, we show an estimate for the aircraft's passage of YQY of 1948z, and an altitude of FL360. The lone little "1" on the right hand side of the strip denotes this is Revision 1, or Rev1, of this flight plan.

This next example is Air Georgian, or GGN, flight number 7463. Also a medium, it's a Beech 1900 equipped with GPS, filed TAS of 270 knots, assigned code 4345. Notice how all the name and type info is on the right side this time? This is because this aircraft is eastbound. Whether the flight is eastbound or westbound for strip production follows the same rules as for cruising level - eastbound is 000-179° magnetic, and westbound is 180-359°. In any case, look at the bottom line again. The aircraft has filed a cruising altitude of 15,000 feet, is departing CYHZ and flying V312 to CYQY. Again, the EP39 is not worth explaining. In the fix posting box (this time on the far left), you see CYHZ as the fix, therefore this is our departure strip. For that reason, we have a time in the smaller box just to the right of the fix posting box, which shows as the pilot's proposed time of departure from CYHZ, of 1635z. Notice in the box just to the right of the time there is a hand-drawn slash in there. This is how we show departure strips. We would put a cross in this section if the strip were an arrival strip, and leave it blank if it were an enroute strip (such as the example above).

We have a manual of strip marking which tells us what we write, where, and how it's supposed to look to show various details such as who this information has been passed to, what altitudes he has been cleared to, methods of showing changes to routing, and so on. If hte aircraft has been cleared for an approach, this is shown in the box just to the left of the GGN's identification, and so on. But these are the basics of what a strip looks like. If it's desired, perhaps I can demonstrate the progression of some strip marking. Interested?

Saturday, June 18, 2005

IFR Non-Radar Control

A comment posted on the article a couple of days ago about IFR in uncontrolled airspace had a question about ATC in the non-radar sense. I'll try to detail it a little, and see what questions pop up.

First and foremost, most ATC systems currently rely, at least to some extent, on paper strips to keep control information on each aircraft up to date. The strips used in Canada are 1" high by 8" wide, and contain details like aircraft ident, type, speed, point of departure, destination and so on. Flight plan route, as well as estimates for various fixes along the way, and altitude information are also kept for reference.

We use a "data board" in the Canadian system, as do a number of other control agencies. Each board will contain at least one "fix posting", which means a geographical location in relation to which our control data is organized. The larger the piece of airspace, the more of these fix postings there are in a data board. For example, a terminal control unit will often have only one "header" in their board, since they're often only concerned with one place, the major airport they're meant to serve. If there are larger satellite airports in the area that they are responsible for as well, they may have a posting for that airport, too. Larger areas, especially those without radar coverage, will often have a number of fix postings. These fixes can be airports, commonly used fixes with significance, such as those where two commonly used airways cross, or they can be a single header that represents a number of fixes that, say, line a boundary area where there isn't much traffic overall. The fixes are generally posted depending on the amount of traffic, and are typically posted if an aircraft over one fix posting is geographically separated from an aircraft over another posted fix.

If an aircraft is crossing a large area, the controller may use several strips to represent the aircraft at individual fixes along the route of flight. As the controller removes the strips from the printer, the flight plan is examined and now a concrete representation of that aircraft is held by the controller, and as it is placed in the board, the controller gets an image of where that flight is going, depending on which fixes have to be posted for that flight. This is also the time for a controller to ensure no other flights are already posted for the same fix at the same altitude at the same time. If one is found, then control action may be required to ensure separation exists prior to that fix (actually, prior to the point where separation is lost). As an aircraft progresses past a fix, the time is noted on the strip, and the altitude and routing is confirmed with the aircraft to ensure the pilot is doing what is expected. If a pilot is rerouted (pilot request or for separation), the strips may be removed from under one or more headers and placed under others to maintain the data board.

In a radar environment, ATC can see Mode C readouts and aircraft positions, so the strips are generally kept more as a backup in case of a radar failure. Altitude changes are noted as pilots are cleared to change altitude, and rough times (perhaps only the sequence of aircraft) are kept as well, just in case. This way, the controller has a place to record information for use with or without radar as well.

Those are the basics of non-radar control. The ways we determine if separation exists between aircraft vary depending on the facilities available in the area (VOR with or without DME, for example), the capabilities of an aircraft (RNAV or GPS, or just the old-fashioned, steam-driven VOR and ADF), and the nature of the airspace involved (controlled vs. uncontrolled, and special considerations like oceanic vs. domestic airspace). If there is interest, perhaps I'll talk a little about some of the ways we look at non-radar separation...

Friday, June 17, 2005

Special Use Airspace

In every region in Canada, we have blocks of airspace set aside for activities and purposes that could be, or are, dangerous to aviation. Rocket ranges, high-density gliding and paradrop activities, etc. There are also areas which have access restricted for security reasons, such as penetentiaries and other high-profile buildings and structures (the Confederation Bridge to PEI has one, for example, to keep flyers away from it under penalty of law).

Their designations often give a clue to the location of the airspace, the activities within, and the nature of the airspace, whether restricted, advisory or whatever. They'll often be noted on charts with letter-number combinations for that very reason. They'll be identified by the characters "CY" denoting for international purposes that the area is within Canadian airspace (including airspace delegated to Canada). Then there will be a letter for the nature of the airspace, a number identifier which also denotes the region it is in, and a letter in parentheses will accompany the designation in the case of advisory areas to denote the type of activity contained within.

For example, CYA306(T) in the Winnipeg FIR is an advisory area, is contained within Saskatchewan, and is designated for training. Whta kind of training isn't really necessary to know, but it is of a concern enough to warrant an advisory area, so the activities inside may be dangerous enough for non-pariticipating pilots to avoid. Also, some areas have more than one activity within, and this is occasionally noted as well. CYA122(A)/(H) is an advisory area in British Columbia, and it contains aerobatic activities as well as hang gliding.

CYRs are restricted areas, and these should be avoided, period. Unless a pilot has the expressed permission from the "user agency", pilots are not allowed to enter these areas. As cited earlier, these may be established for rocket ranges or security reasons, or whatever else, and pilots must remain clear. The "user agency" is defined as the person, group or establishment for which the CYR was established for, and they are the only group who can grant permission for entry. Sometimes these groups will authorize ATC use for a period of time, but again, it's these groups that have the final say. CYR724, near Fredericton and Saint John, NB, is a prime example, since it is statistically the most violated restricted airspace in Canada, despite it being charted as "continuous live firing to FL250".

In review, they are named as follows (reference AIP Canada, RAC2.8.6):
-"CY" for Canadian nationality;
-"R" for restricted, "A" for advisory, "D" for danger (international waters only)
-3-digit number denoting region and name within
100-199 British Columbia
200-299 Alberta
300-399 Saskatchewan (that's as hard to type as it can be to say)
400-499 Manitoba
500-599 Ontario
600-699 Quebec
700-799 Atlantic Canada (maritimes plus Newfoundland)
800-899 Yukon
900-999 Northwest Territories (including Arctic Islands)
-Letter(s) in parentheses for advisory areas
A for acrobatics
F for aircraft flight test areas
H for hang gliding
M for military operations
P for parachuting
S for soaring
T for training

Thursday, June 16, 2005

Information Requests

Currently, I'm holding the post of FIR Chief for Moncton and Gander within VatSim (although in reality, Moncton and Gander Centers are under separate management). This post has caused some interesting questions to be fired at me over time. Since NavCanada doesn't host websites for the various regions, when people do searches for the regions by name, the websites designed by VatSim "staff" and hosted for online flight activities often receive the hits for people looking for real world information. There are many folks interested in getting information on Oceanic airspace, for example, and the internet has become a favorite choice for research, rather than official documents. It also seems that no matter how many times you mention that a particular site is meant for flight simulation, some people completely miss it and still believe it's something for the real world. Kind of like hearing what you want to hear.

In any case, I have fielded many questions about oceanic procedures, airspace requirements, and most often requests for tours of a given facility. Just recently, an e-mail arrived in my inbox with the name and rank of a naval officer claiming he was a controller on board the Charles de Gaulle aircraft carrier just off the coast of St. Pierre et Miquelon, a couple of islands south of Newfoundland that belong to France. The ship was in Halifax recently after a multi-day exercise off the coast of Nova Scotia. He said he wanted to know the classification of oceanic airspace east of Newfoundland. I don't know the e-mail was real, but at least I had the answer for him. (Class A, if you wanted to know)

Many pilots who are planning stopovers in Gander, for example, on transatlantic flights ask for a tour. Why wouldn't they? It would be interesting if you've flown across the pond a few times to have a look at the inside. Fortunately, I can answer many of the questions. There have been several that I've been able to ask someone else about. A C-5 captain from the USAF recently asked me if Gander could provide HF DF steers. I found nothing published about such a service, and it turns out, when I call Gander from work, that they can't provide DF steers on any frequency they use. Then there are the questions that only a manager can answer, and all I can do then is refer them to the real person.

I always identify myself as nobody involved with the management or functions of the real world Gander facility, though if the question relates to Moncton, I will tell them that I am a controller there and get them to contact management, if such a question requires a real world answer from them. I'll say this: People looking for real world information shouldn't be contacting me from our simulation websites, but I've met some interesting people and fielded some interesting questions along the way. And, as it has been since I started writing publicly, have learned a few things along the way. And that's what keeps me going on this.

Wednesday, June 15, 2005

IFR in Uncontrolled Airspace

Paul Tomblin asked about a comparison between US and Canadian regulations for IFR flight in uncontrolled airspace. I'll detail this a little here.

For an example, we'll take a flight that is outside of controlled airspace from departure point to destination. A routine example in the Moncton FIR involves Bathurst, NB (CZBF), again, and Charlo, NB (CYCL). While CYCL is not the facility it used to be, it remains an active aerodrome, particularly this time of year when the fishing is awesome in northern New Brunswick.

Our sample flight will depart CZBF and proceed NNW to CYCL at 4,000 feet. The airspace here is, of course, Class G, with Class B above starting at 12,500 (well, immediately above 12,500 as discussed yesterday). Since our altitude is well below the base of controlled airspace, IFR aircraft do not need to receive an IFR clearance to operate. This means that the departure, the entire leg of the flight and the approach, regardless of weather, may be made without talking to ATC at all. It is highly recommeded that such a flight check in with ATC, since ATC should be aware of other IFR traffic operating within the area. Also, as recommended by the AIP and routinely practiced, position reports should be made on 126.7 (or another frequency, if established for the area as published in the Canada Flight Supplement). This way, pilots may obtain traffic information from ATC as well as current positions of IFR and VFR traffic in the area that aren't talking to ATC.

Under Canadian regulations for IFR flight, an IFR flight plan or flight itinerary must be filed. The conditions allowing an IFR flight itinerary really only include the most remote fields, so we'll only talk about the flight plan option. The difference is subtle, but important. ATC will provide alerting services for the aircraft. This means that if ATC doesn't receive a departure message within one hour of flight planned departure time, somebody is going to go looking for your flight. This is to protect for the possibility of a crash on take-off. Similarly, ATC will be looking for an arrival report to ensure a safe landing has been made. In addition, once ATC knows you're airborne, they can relay traffic information to other IFR aircraft operating in the area so these pilots know you're out there.

Now, other regulations that apply to IFR flight in controlled airspace still apply in uncontrolled airspace. In Canada, the rule is 1,000 feet above the highest obstacle within 5 miles of the aircraft, but this is sometimes higher, too. There are five Designated Mountainous Regions in Canada which require either 1,500 or 2,000 feet above the highest obstacle within a 5 mile radius instead of the normal 1,000 feet. These areas are the Rocky Mountains, the eastern side of the Canadian archipelago (the islands way up north), the island of Newfoundland, northwestern New Brunswick (a continuation of the Appalachian Mountains) and eastern Quebec/Labrador. The Rockies and the islands up north require 2,000 feet, the others require 1,500 above. Also, on the flight plan, you are required to ensure ATC receives a departure message and an arrival message (which may be relayed to the IFR ATC unit directly by radio or telephone (if no radio frequency is available) or to the ATC unit via a FSS by radio or phone. Altitudes flown shall be the same as those within controlled airspace (even thousands westbound, odd thousands eastbound). As mentioned, position reports should be made on appropriate frequencies. Where an ATC unit is reachable, make these reports to the ATC unit, and it is also recommended practice that position reports also be made on appropriate enroute frequencies (126.7, unless otherwise specified) if practical. All other requirements normal to IFR flight apply as well, such as aircraft lighting and equipment, weather minima for take-off and landing, requirements for alternate aerodromes and everything else you can think of.

Tuesday, June 14, 2005

Base of Controlled Airspace

In Canada (as elsewhere, but I'll only speak for us), the base of controlled airspace depends on the area where you are. In the southern areas of Canada, the base of controlled airspace is much lower than in the far north. The Arctic Control Area, the far north of Canada's archipeligo, has Class A airspace based at FL270. The Northern Control Area is based at FL230, and the Southern Control Area, where all the most populous places are, Class A is based at FL180 (or more correctly worded, "18,000 MSL and above").

Class B is considered to be "controlled airspace above 12,500 up to, but not including, 18,000 MSL". Therefore, if it's classed as controlled airspace between these two levels, it's Class B. An example of where Class B begins above 12,500, could be an airway. Airways are controlled airspace which begins at 2,200 above ground level. A mountain topped at 14,000 feet would push up the base of controlled airspace of an overlying airway, and therefore the "floor" of Class B airspace, to 16,200 feet. Below that would be Class G.

The trick is to read the charts to see where the base of controlled airspace is. A Canadian LO chart (low level enroute) has areas shaded with solid green as uncontrolled below FL180. The cross-hatched areas (green with white lines) are drawn to denote areas where the base of controlled airspace is "above 12,500", meaning Class B. The areas without shading (white) denote other levels, which may be 5,500, 2,200, 1,700, 700, or indeed any other specified level (the three latter examples are common values expressed in elevations AGL).

The example flight I mentioned the other day about the Dash 8 meeting another piece of aluminum was around Bathurst, NB (CZBF), where the base of controlled airspace on the Canadian side of the US/Canada border is above 12,500, while the base on the other side is much lower. One reader posted about US airspace and there not being much Class G. Interestingly, another difference between Canadian and US airspace is that US IFR approaches much be contained within controlled airspace. This is not a requirement for Canadian approaches, and there are many examples of airports which underlie controlled airspace but have one or more approaches published.

Sunday, June 12, 2005

ATC Radio Chatter

A few short ones from Moncton ACC over the years...

VMC, pilot has the airport in sight, he's number 2 and been told there will be a delay.
"Are you ready to copy a long and detailed holding clearance, or do you want to do the honourable thing and cancel IFR?"

"ABC123, you best man the stick. There may be a hard turn coming."

Controller to controller conversation...
"I didn't hear a thing that guy said."
"Sounds like a good place for a 'roger'."

Controller to controllers around him after letting a rip-roaring, wet-sounding fart at the sector...
"Pick the bones out of that one!"
... only to find out a ladies group was right behind him on a tour of the facility.

Saturday, June 11, 2005

IFR in Uncontrolled Airspace

Some time ago, we had a little situation that I was reminded of last night. Bathurst, NB (CZBF) is below the base of controlled airspace, which is "above 12,500". This means, for those who don't know, that 12,500 is actually uncontrolled, but anything above that is. An aircraft departed CZBF westbound, with an IFR clearance to "maintain 10,000 in controlled airspace." This means exactly what it says: when you enter controlled airspace, you had better be at 10,000. Before entering controlled airspace, ATC doesn't have the authority to direct your flight, so you may do what you want. This pilot departed and reported climbing to 10,000, and everything seemed normal.

We also had an IFR aircraft cruising at FL230 who began descent into CZBF from the west. With our traffic at 10,000, and therefore in uncontrolled airspace, our obligation is to clear this aircraft out of controlled airspace and inform him of the traffic. Both were on radar, so radar traffic information was passed. As the two closed, the Dash 8 pilot informed us that he didn't have the traffic in sight, and was planning to stop his descent at 11,000 and asked us to inform him when they passed. While the tracks were not exactly opposite (the eastbound Dash 8 would pass about 2NM north of the westbound aircraft), they didn't want to drop below 11,000 anyway. Then, the controller working the two airplanes noticed that the westbound aircraft had taken a turn to the right of about 20°, this making his track coincide nicely with that of the Dash 8 about 10NM ahead. Since the pilot said nothing about climbing above 10,000 and the Dash 8 had already told us he was stopping at 11,000, nothing more was thought at this point. Then, after "putting out a fire" somewhere else in the sector, the controller noticed that the westbound aircraft had climbed through 10,000, still pointing at the Dash 8. The pilot was querried, and he responded that he was "deviating for a buildup,"and had climbed to 11,000. A perfectly legitimate manoeuver, but given that he had been told about the Dash 8's position and intentions, it's awfully interesting that the pilot would choose not to say anything either to the controller or the other pilot. As it turns out, they passed fairly close (not enough to engage TCAS, but enough to excite the Dash 8 pilot and bug the controller) to each other both laterally and vertically.

The pilot of the westbound aircraft was perfectly within his rights to maneouver without approval of ATC, since he was operating within Class G airspace. The choice of maneouver is a question, given that he had been told of the position and intentions of the Dash 8 (who didn't like what he saw). But I'm recommending that a pilot keep someone in the picture when he decides to do something that's not expected of him. His last words indicated he was climbing on course to 10,000, but obviously that had changed. Had he done what he had told us he was doing, they wouldn't have been traffic for one another. Had he told us about his modified plan, this information could have been passed to the Dash 8 (if he didn't hear it directly from the pilot over the radio) and they may have chosen to act accordingly and steer away from him themselves.

Friday, June 10, 2005

Air Canada Boeings

I didn't yet write about this, but I read a while back that Air Canada was looking at B777 and the new "Dreamliner" from Boeing. They had orders for some that were described as "firm", and then in yesterday's paper I read a little blurb in the buisness section that these orders were in jeopardy due to the lack of an agreement between Air Canada and the pilot's union. Damn those unions, eh? I see letter after letter in the editorials section of our newspaper blaming everything on unions and how they've outlived their usefulness and so on. Unions have not outlived their usefulness, in my opinion, and are there to protect worker groups against injustices often served up by their employers.

Back to the original note, I read a followup in today's paper that a tentative agreement has been reached, and that the order may yet go ahead to see Air Canada taking on more Boeing products. It'll be interesting to see some new types of airplanes in a Canadian airline's fleet. I just hope they fly my way eventually. Although I have a relatively large collection of airplane pics, I'm always willing to add to them.

Thursday, June 09, 2005

ATC Radio Chatter

Not Canadian, since altimeters here are rarely referred to as QNH and never in millibars unless requested (and almost nobody requests it), but I found it funny nonetheless.

ATC: "Pan Am 1, descend to 3,000 ft on QNH 1019."
Pan AM 1: "Could you give that to me in inches?"
ATC: "Pan Am 1, descend to 36,000 inches on QNH 1019"

Wednesday, June 08, 2005


The good folks from Aviation.ca wrote me about a post I made back in February. The one about the PA-28 in the thunderstorm. They wanted to publish it there, and I'm quite happy about that. Anyway, it's done, and it can be viewed again on their site.

Incidentally, their site is dedicated, as the title says, to aviation in Canada. This, as you might guess, is right up my alley (the title of my blog is kind of a giveaway, isn't it?). They have forums, wallpaper for your desktop, and all sorts of other things there, including articles posted by various people involved in the Canadian aviation community. I intend to watch this, hoping it grows over time. Here's a link. Check it out.


Tuesday, June 07, 2005

Communication in Abnormal Situations

Recently, a regional airline that flies in the Moncton FIR was flying from one airport to another. Upon reaching destination, the regional turboprop cancelled IFR and circled the destination airport for a short period, telling the FSS there that they 'were checking something'. Eventually, they decided to head back to their point of departure. When they called for and received their IFR clearance back, I asked if they needed any assistance, and was told, "everything's fine". They continued to destination and while on about a 7 mile final, radioed to the tower that they had an unsafe gear indication and were requesting the fire trucks to stand by for their landing.

Think about this for a minute. Why would the pilots withold such information for so long? What they ended up doing is scrambling the crash crews at the last minute, rather than giving them a heads up. Most pilots I've experienced such a problem with, especially given that the flying time between the original destination and their final destination was 30 minutes, would have communicated the situation, allowing the crews a decent time to prepare for their arrival. Think about it: Would you like to have the boys ready to help, or starting from zero and accelerating to 60 with no notice whatsoever? And why keep this secret from ATC? I know we can't push a button and fix his gear problem, but we have direct lines to other resources which may be able to help. I don't understand. Perhaps a pilot reading this can offer some suggestions as to why this pilot would have held off for so long about his situation...?

Monday, June 06, 2005

False Hijacking Alert

By now, everybody and their dog must have heard about the false hijacking alert on a Virgin Atlantic A340 recently. I was working the day this guy came in to Halifax. It was a bizarre situation, and we knew something was odd before they isolated what the problem was. It's not often that a airline gets involved in where to divert a hijacked airplane. If the pilot is choosing an alternate destination, it's not normally someplace like a small Canadian city.

Since everybody knows the details that I write here, I don't feel like I'm speaking out against the rules of the company I work for. Heck, people in CNN knew about the "hijacking" early enough to report the original destination, my hometown of Moncton. The idea of coming here didn't last long, and instead they diverted to Halifax. News travels fast these days. The thing that really disappointed me in all of this, now that the outcome was little more than an inconvenience, is the callsign our military fighters used. AGLET1 and 2. Aglet. Do you know what they are? They were called "flooglebinders" in the movie Rainman, I think it was. The little plastic things on the ends of shoelaces that prevent them from fraying. Come on, why couldn't we see something a little more manly? Or at least, meaningful...

Sunday, June 05, 2005

Use of TCAS as a Radar

I remember when TCAS started proliferating in aircraft around the Moncton FIR several years ago. Some of us were quick to criticize it, while others realized the value in pointing out traffic to pilots. Then there were some pilots who used it, in my view, in inappropriate ways.

One pilot called me to criticize my judgment regarding an aircraft in front of him, which I may have even written about recently. My memory isn't all that great. Turns out, he knew we used to need 10NM between aircraft in that airspace, claimed his TCAS showed only 9 between him and his traffic (there was 14 on my radar which has been flight-checked for accuracy), and we had recently switched to 5NM separation there. Don't get me wrong, by the way, I'm all for cross-checks and I never take this sort of criticism too seriously. If someone sees something that is dangerous and I don't, I'd much rather tell me about it than let things degrade, possibly to the point of no return.

Anyway, the real point of this is the use of TCAS in ways which may not be good. I've long wondered how useful TCAS would be as a radar tool for a pilot, since there is no "trail history" to show where the aircraft was coming from, no groundspeed or "predicted track line" to show where he's going. Just a target, drawn with azimuth and a range (and the altitude difference, of course). With the lack of any indication of what the other aircraft is actually doing, it doesn't show the much-needed information to the pilot when the thought of using it to make his own judgment about avoidance manoeuvers. The good part of this is that you no longer have to take my word for it. IFALPA did up a really nice presentation in Adobe Acrobat's PDF format that demonstrates real-world pilots making avoidance manoeuvers based on TCAS observations that caused problems where separation was being looked after. I've included a link at the bottom of this page, with no guarantee how long this PDF will sit at this location. Please have a read of this, and let me know what you think. It tells the story I've long been thinking about (and even arguing about from time to time), but lacked communication skills to describe, and also lacked real-world examples of the dangers.


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.

Thursday, June 02, 2005

Aviation Safety Letter and Me

I have mentioned the Aviation Safety Letter, a publication distributed with the AIP amendments, many times in this blog. It's one of the few publications, short as it is, that actually holds my attention long enough to allow me to read it cover to cover. Paul Marquis, the editor, contacted me recently. He found my weekly topic website while doing some recent research. After taking a brief look at one of the topics, he contacted me to offer compliments, and made an open request to see about the possibility of using some of my material in the ASL. Imagine how honored I feel. Regardless of whether he actually uses some of my stuff, I am absolutely flattered that he would feel my works good enough to make it into this magazine. I'll keep you posted here if anything further develops.

Wednesday, June 01, 2005

Transponder Airspace

While some of my buddies laboured under CAATS implementation, I chose to go mountain biking and later went flying. What a day! Winds were strange (running mostly light and variable, but shifting a lot with the occasional gust out of nowhere up to 15 knots, such as when I was about to touch down). What a great day!

My flight had me checking out that waterfall again. On the way out I had planned around going up to 6,500 feet, VFR of course, taking some photos and examining the area, then descending for a closer look, the climbing back up to 5,500 for the return trip home. What I didn't count on was the lack of a transponder in my plane. It went U/S, so I was going stealth, it would appear. Funny thing is, it took a reminder from club personnel (Beth does a great job of keeping me out of trouble, fortunately) about the Transponder Airspace around Moncton. It's Class E Transponder Airspace, so I don't have to talk to ATC while in it, but a transponder with Mode C is required for operation within it without prior approval. One would think I would have been keenly aware of it, since I work that airspace from the ATC side every working day. How embarassing. Thanks, Beth!

Anyway, it made for a bit of a bumpy ride on the way out and the way home, since now I was restricted to below 3,000 over the hills in southeastern New Brunswick, but it also made for some great views of the back country terrain and winding creeks and rivers in that area. I am always amazed at the views in that area. I have to force myself to look out the window for traffic, since I know the area well enough to find my way without looking for the airport from there, and I'm so taken with the region. You can only fulfill your part of "See and be seen" when you're looking for traffic.