Aviation In Canada

Monday, January 31, 2005

Smoke in the Cockpit

In Moncton Center, we're in the midst of recurrent training. Each year, ATC in Canada are required to undergo a refresher which addresses topics that are deemed essential for refresher, and some local items also creep in (though we would like to see more of this stuff). This year, in-flight emergencies are being addressed once again.

Swissair's flight 111, the MD-11 that crashed into the waters off Nova Scotia in 1998, is one incident that hits close to home for Moncton Center. Simply because it was close to home. The aircraft suffered a catastrophic in-flight fire, ultimately leading to the loss of 229 lives about 25NM off the coast of Nova Scotia, a province on the east coast of Canada. As one controller who worked the flight said, it's a tough feeling to describe. The idea of watching a radar target, knowing the situation, and being able to do absolutely nothing about it. The fire broke out and consumed the cockpit so quickly that there was literally no chance of a safe landing. Though many people have their own opinions on how things "should have gone", I have yet to find an argument which would have led to a safe landing. Some say the pilots should have driven right into the airport, landing overweight. Flight data recorders along with a radar timeline have proven that the aircraft drove in very fast all the way down, and yet still wouldn't have made the airport given the time they had before impact.

Speaking of time, one thing our guys found in researching reports for their presentation struck me as very interesting. The Canadian Transportation Safety Board researched in-flight fires in incidents between 1967 and 1998, and found the average time between the detection of an in-flight fire and the forced landing, ditching or crash of the aircraft was a mere 17 minutes. They ignored safe landings, since these were not reflective of what happened in the Swissair 111 incident. Of the 15 incidents examined, some lasted as much as 20 minutes, while some lasted less than 10. Swissair 111 made the average. When they detected the fire, they were 20 minutes from the runway. Had they made a run for the airport, it is likely they would have plummetted into downtown Bedford, probably killing many more on the ground, too.

Here's the link to the Transportation Safety Board's website and the report where I found this. The study is mentioned in Appendix A, but the rest is worth a read, too. Have a look:


Sunday, January 30, 2005

ATC Software Evaluation

I just returned from a trip to Ottawa to help out a large group of individuals in testing CAATS, Canada's next generation of ATC software. This is why there was no post on the 28th, in case you're wondering. Originally, it was supposed to be an all-encompassing, stripless environment. For those who don't know, many ATC units around the world are used to using paper strips which contain flight plan information to maintain clearance data and coordination data with other controllers. Over the last two decades, maybe three, many studies have been undertaken and several countries have attempted to remove the strips from the ATC world and maintain everything electronically. Most controllers have rejected the idea, since these safety-minded individuals are conscious of the fact that computers can freeze up, or spontaneously reboot. If that happens to the whole system at once, what do you do? At a slow time with only one aircraft, that's easy. If you are in a full-blown furball of traffic, which is when a computer will likely have problems due to workload, it's an awful lot harder to deal with.

Anyway, the system is still supposed to produce strips for us, as well as add some functionality for controllers to work with. It has come a long way, but it still has a long way to go before being ready. I needn't say much more about it, really. The idea of trouble-shooting a program can be a troublesome task, but when your program has extremely complex algorhythms and over 1.5 million lines of code, it's so much harder. The guys building it have their work cut out for them. And they're quite a bunch, really. It was good to meet them and hear of their challenges in the process, too.

Saturday, January 29, 2005

Block Altitudes

I mentioned a few days ago the concept of "Block Altitudes". I hope to fill that gap now.

Sometimes a pilot may have difficulty maintaining altitude due to weather conditions or some other reason. Perhaps strong turbulence is becoming a problem, you're riding the tops of cloud in and out of icing, whatever. An option open to pilots is a block altitude. ATC doesn't provide clearances to aircraft in blocks of altitudes without a pilot request. The request for the block normally must be accompanied by the reason for the request. This is more of a rule ATC is required to follow, rather than just ATC being nosey. Controllers have a number of conditions they are supposed to meet before approving a block altitude. They have to know what the reason is, and when you can return to a "hard altitude". This last one is difficult in some circumstances, since a pilot or a controller likely won't know when icing conditions will end. They also have to see you meet certain requirements that you may not even be aware of.

Your flight must be a training flight, flight checking a NAVAID (and no, the average pilot can't qualify for this one), or you must require it for fuel reasons, turbulence or icing. This is the same as the rules for an altitude inappropriate for direction of flight (5,000 feet for a westbound aircraft).

The phraseology ATC will use for assigning a block altitude will sound something like, "Alpha Bravo Charlie, maintain the block from six thousand to eight thousand." Some will say, "... maintain six blocking eight thousand," but it means the same thing.

When a block altitude is no longer required, a pilot should endeavor to maintain an appropriate altitude for direction of flight within the assigned block, or request a different altitude, and advise ATC the block is no longer required. ATC should then issue a clearance to maintain the desired altitude, implicitly cancelling the approval for the block.

Thursday, January 27, 2005

"Wrong Way" Altitudes for IFR

The Canadian Aviation Regulations are quite specific on the subject of altitudes appropriate for direction of flight. For an eastbound flight (defined as any flight with a magnetic track between 000 and 179°), the IFR pilot should be flying at an altitude which is an odd number of thousands. 3,000, 5,000, 7,000, FL190, FL230, etc. For a westbound flight (180-359°), it should be an even number of thousands, like 4,000, 8,000, FL200 etc. This extends into RVSM airspace as well, up to FL410. Above that, it's two thousand feet between levels. Another topic, maybe?

There arise occasions where a flight needs an inappropriate altitude. For example, a Dash 8 riding the turbulent tops of cloud at FL240 may request FL250, since the service ceiling with passengers is FL250 and therefore FL260, the next appropriate altitude, is not available. In controlled airspace, ATC may assign altitudes inappropriate to the direction of flight under certain conditions. First, the reason for the request must be given by the pilot, and it must be because of icing, turbulence or fuel considerations. Additionally, a pilot who is flight checking a NAVAID, holding on a fix, or in training may get approval for this. Medevac flights may receive a clearance for an inappropriate altitude, as well. One of the things ATC is supposed to do, to toe the line with CARs, is to ask the pilot when fight at an appropriate altitude can be resumed. This may be difficult, since it is rarely known how long the conditions requiring the altitude will extend. A best guess should be provided to ATC, and controllers should be understanding that it may not be as stated in the end. As soon as it is practicable, the pilot should request a clearance back to an appropriate altitde.

Wednesday, January 26, 2005

Circling Procedures, Part Two

Now that we determined in yesterday's post the requirement for an ATC clearance for a circling procedure, we should look at another important aspect. Just how far back from the airport can you start to circle for the other runway?

There are prescribed distance for this, and the distance depends on the category of the aircraft, which in turn depends on the speed of the aircraft on final. There are five categories, A through E, and the further along the alphabet, the faster the approach speed. Most jets fall into the C and D categories, while lighter aircraft typically fall into the A and B. Category E aircraft are military fighter jets, and not all approaches are drawn up to include Category E. Allowed categories for each approach will be denoted, along with weather minima for straight-ins and circling procedures, in the approach minima box at the bottom left of the approach plate. If there are no published minima for the procedure, it was not assessed, and therefore not allowed.

In any case, the area where a circling procedure can be initiated is as follows. The AIP Canada has a diagram which describes it better in RAC 9.3, as does my Weekly Topic from two years ago available by clicking here. Arcs are drawn around the runway thresholds, and lines drawn between the point of tangency of each of these arcs. The radius of the arcs is dependent upon the category of the aircraft, and is not more than 2.5 NM for a Category D aircraft, slower aircraft getting less distance. This is to allow for lower weather limits for slower aircraft, taking into account the smaller geographical area covered at lower speeds. Generally speaking, if you're cleared for an approach with a circling procedure, you still have to complete the instrument approach procedure before starting to circle. Starting the "circling manoeuver" before even making the Final Approach Fix is just not right. Doing so may very well affect separation between you and other aircraft in the air or departures launching before your arrival.

Tuesday, January 25, 2005

Circling Procedures, Part One

Often the weather requires use on an instrument approach aid to break cloud, but dictates the use of another runway not aligned with the approach to be flown. For example, Fredericton, NB (CYFC), has no IFR approach on RWY 33 due to restricted airspace. If the winds are hard out of the northwest, but the ceiling is down around 900 feet, how does an aircraft who requies the use of 33 get in? He may fly any one of the other approaches published for the airport and circle to land on 33.

First things first, he needs a clearance that permits it. "... cleared to the Fredericton airport for the straight-in VOR runway 27 approach, circling for runway 33." This allows the pilot to circle for 33. Without such a clearance, ATC is not anticipating a circling procedure, and it may affect separation. Should a clearance for a circling procedure be required, all a pilot needs to do is ask if he hasn't be offered the option.

More to follow in tomorrow's post.

Monday, January 24, 2005

Approach Naming, Part Two

Continuing yesterday's topic, ATC should be clearing you for a published approach as it is named on the plate. For example, the clearances should sound like, "Alpha Bravo Charlie cleared to the Fredericton Airport for the ILS DME runway 09 approach". This confirms which approach the pilot is cleared for, and reminds the pilot of the nature of the approach. For example, if the pilot without DME hears the DME part of the clearance, it should twig him to realize he's not supposed to do this approach, and he should request an alternate clearance. The only example of a place where ATC is not supposed to assume the pilot is capable of conductin an approach is the RNAV (GPS) approaches. All other approaches, ATC may assume the pilot is capable, since basic NAV gear should include the rest. In Canada, Localizer Back Courses fall under the umbrella of "standard" capabilities.

Additionally, the clearance should give the pilot some information such as the nature of the transition to be made for for approach. If ATC specifies the approach name as in the above example, a straight-in is not authorized and ATC is expecting you to do a procedure turn. This may be required for separation between you and aircraft departing the airport before you land. For a straight-in, it must be specified in the clearance. The only exception to this is a clearance to fly an approach via an RNAV STAR. "...cleared ILS runway 24 approach via the FUNDY 6 Arrival" means the pilot is actually expected to fly the approach straight-in, since the straight-in is considered part of the RNAV STAR procedure. Please note that the FUNDY6 in the above example is built as an RNAV STAR, not a PILOT NAV STAR.

Sunday, January 23, 2005

Approach Naming, Part One

The topic of approach naming has a few different facets to it. First off, the name of the approach on the approach plate gives an idea of what NAV gear is required for the approach. For example, to fly an "ILS/DME RWY 09" requires DME. Without a serviceable DME on board, the pilot is not permitted to fly that approach. DME distances may be marked on a chart, but if the approach were to be named "ILS RWY 09", then there is no requirement for DME, and the DME distances marked may be used for reference in lieu of other means (crossing bearings of neighbouring NDBs and such).

Part two coming up in tomorrow's post.

Saturday, January 22, 2005

"Descent at your discretion"

Until a few years ago, Canada and the US differed on the meaning of the phrase in the title. Now, I believe the books read the same way.

When issued a climb or descent at pilot's discretion, the pilot has the option of starting the altitude change when he wants to. Also, a pilot is allowed to stop the climb or descent at an interim altitude. The further descent or climb clearance is also still valid, so they can continue climb/descent without further approval from ATC (unless the clearance is not subsequently cancelled, that is). The pilot must climb or descend at a rate that is consistent with the aircraft type's performance when climbing or descending. This means that "descend at your discretion" does not constitute approval for a "cruise descent". If a pilot wants a slow descent rate, that should be asked for separately to keep ATC in the picture. Additionally, once an altitude is vacated, the aircraft cannot return to that altitude. If a pilot may wish to climb and descend at will, perhaps skimming tops of cloud or such but wishing to remain out of them, then he should request a "block altitude". I'll write more on that in an upcoming post.

Friday, January 21, 2005

RVSM is here!

For some of us, RVSM has been a reality for some time now. In my own building, Moncton Center, RVSM was introduced back in 1997, in a limited fashion. Our guys have been dealing with it to and from the North Atlantic since then. Now, it's here in its entirety. Everything over North America (right down into Mexico), the North Atlantic (including WATRS airspace over the Carribean) and into the Pacific is all RVSM exclusionary airspace.

In the past, non-RVSM certified aircraft were allowed to operate within RVSM airspace. Now, outside of exceptional circumstances, the only way they're allowed to run in RVSM airspace is if they are climbing or descending through it. If you're not "/W", the equipment suffix for RVSM, you're staying at FL280 if you can't make FL430. This was, of course, as it has been in many areas around the world, such as the oceanic airspace between Europe and North America, but the exclusionary part of RVSM is new to our domestic airspace. Most of the regular operators in our region received the certification on time to prevent restrictions on their flights, so if anything, it's pretty much "ops normal" around our skies.

Thursday, January 20, 2005

Another Winter Storm

Another winter storm is getting ready to slam the maritime provinces of Canada where I live. (the maritime provinces, for info sake, are New Brunswick, Prince Edward Island and Nova Scotia) The neat thing about this one, from an aviation standpoint, is the wind forecast. We often see a change of winds of around 60-90°, but this one is forecast to start blowing from the southeast, change to the northeast (where most of our nasty winter storm winds come from) and then to turn to blowing from the northwest, all with high winds upwards of 25-35 knots before the gusts are factored in.

The great issue surrounding this is the high winds dictate the runway usage, whereas most operations in our region are dependent on the pilot's desires and traffic. In calm winds, even the busier Halifax International uses all the pavement to get airplanes off and on as quickly as possible (the beauty of a great control staff and no noise abatement procedures or other restrictions). No, this way the winds will have it. Which runway do the plow drivers clear? Take Halifax, for example. Initially, with the winds out of the SE, they'll likely plow runway 15. It has an ILS and points the right way. With budget cuts all over the country, what happens when the winds change to NE? 06 will be needed, but it'll have snow on it and be very slippery. Can you still have airplanes landing with a 90° crosswind in slippery, snowy conditions? The good news is that when it clears off, the winds will be from the NW, looking right down the reciprocal of runway 15. But then, did they take the plows of 15 and start working on 06 before the snow stopped falling? This could mean both runways are now slippery. What a challenge for the pilots!

Wednesday, January 19, 2005


Have you heard of VatSim before? If you're not into computer flight simulation, you probably haven't. Even if you are, you may not have heard of it.

A few years back, a couple of guys got together to provide the something that the flight simulation community had been begging for for years: Air traffic control. Some companies had tried to build ATC into flight simulator programs in the past, but none of them did it successfully. All of the major simulator programs have either built-in modules to provide something for ATC, or add-on products are available, but let's face it: a computer can't yet make decisions and react to humans the way a human can -- for better or for worse.

The way they did it was to build a pair of programs. One sat on the pilot's side, reporting position and altitude to a server. The other program was the controller client, which read data from the same server and displayed it on the controller's screen. Seems pretty simple, doesn't it? Get many pilots from all over the world flying many different aircraft in many places all over the world, and the controllers working sectors divided up as mirror images of the real world, even with the names of the real ATC centers. Suddenly, with internet voice capabilities, you have real time interaction between simulator pilots and virtual ATC. The servers even take real world weather sequences and load them into the flight simulator. The best part is this: It's all free.

The software in use was written by groups/individuals in their spare time. Right now a mishmash of programs are being used, but newer software is in development to combine needed features into an easier-to-use package. The servers they use are companies which are willing to volunteer extra bandwidth and space on their servers. There are groups of individuals around the world providing an organizational structure to help govern this and make sure it moves and stays fresh. The procedures in use are closely mirrored to real world ones, thanks in no small part to the dedication of the individuals in these groups. People with healthy appetites for realism and/or connections do the footwork that helps keep this whole world as real as it can be for those who want to fly in it. And since major flight simulation software has scenery for the entire world, a pilot can fly anywhere in that world and will often have ATC online for his flights. Many groups have even organized virtual airlines, painting up models and building route structures, often based on real world airlines.

VatSim is just one of the virtual ATC networks out there, but it's the only one I've engaged in. I fly online as a pilot, though not for a virtual airline. I also participate in the ATC department, attempting to use my real world skills and knowledge to help those flying in my area enjoy an experience as real as I can make it for them. Being able to help some pilots and some other controllers learn some procedures and have some fun is what started my Aviation Topic of the Week some time ago, and the encouragement I received from those efforts are what started this whole blog. I'm happy to contribute to this virtual world when I can, and hope to continue doing so. I've learned an awful lot in the process of all of this, and that's what keeps me going.

To find out more about VatSim, follow the link provided here. You can learn more about the orgnaization as a whole, and become part of it, should this concept interest you. http://www.vatsim.net

Tuesday, January 18, 2005

Radio Conversation

A controller in Halifax Terminal, a good friend of mine with a sense of humor had the following exchange recently. GGN is "Georgian", a regional airline from Ontario flying routes in the QM FIR. They were flight planned at 17,000 HZ-QY in a Beech 1900D.

GGN7476: "Halifax, GGN7476 requesting 11,000"
HZ TCU: "GGN7476, maintain 11,000"
GGN7476: "Climbing to 11,000, GGN7476"
a short time later...
GGN7476: "GGN7476 requesting 13,000"
HZ TCU: "GGN7476, maintain 13,000"
GGN7476: "13,000, GGN7476"
another short time goes by...
GGN7476: "GGN7476 request 15,000"
HZ TCU: "GGN7476, maintain 15,000"
GGN7476: "Up to 15,000, GGN7476"
GGN7476: "GGN7476 would like to climb to 17,000"
HZ TCU: "You're one high maintenance beech..."

Monday, January 17, 2005

Turning Back on Take-off

The latest edition of the Aviation Safety Letter, found in this month's AIP amendments, focused on the idea of turning back to the runway used for take-off upon an engine failure on take-off. Current wisdom drilled into people's heads during training says that unless a reasonable altitude has been reached, a pilot should never consider this. Case in point, in one incident talked about. The pilot of a float plane attempted this, and in classic style, ended up in a stall condition and contacted a marshy area of the lake he was attempting to land on, with the plane coming to rest inverted. Have you ever tried this? How high is a "reasonable altitude"? I haven't yet seen an aircraft manual that describes this. Nor would I expect to, given the number of variables involved.

Take any flight sim and get in your favorite single engine aircraft(for some, this may require backtracking a few years in their flying career) and set up on a runway. Add 5-10 knots of wind to the equation, for a greater challenge. Get airborne, climbing straight out, and as soon as you think you have enough altitude to make the turn back, do it. Don't just cut the throttle, kill the engine altogether. Pull the mixture, shut off the magnetos, whatever is quicker. When the engine has died, not before, make the turn back. See just how capable you are from the altitude you've chosen. Don't make this easy and say you'll do it from 3,000 feet AAE. Make it more realistic by starting from the lowest altitude you would really try this from. I'd be interested in hearing your results. Include, if you respond to this, aircraft type, airport elevation (since that makes a difference), runway length, altitude chosen and the success or failure. Don't fly to the end of a long runway before turning back, either. Kill the engine as soon as you reach what you think is a "reasonable altitude" and start the manoeuver. Be honest, now. Learn from it, too. Maybe flying straight ahead really is the best option.

Sunday, January 16, 2005


I mentioned before about ILS being protected by ICAO as the primary precision approach aid until 2010. Many of us are quite eager to see more changes sooner, rather than later. A few airlines are taking leading roles in flight checking GPS precision approaches. From my perspective, something new can't come soon enough.

ILS is great, I agree, but why is it that when the worst weather comes, the first thing to go is the ILS? Snow is bad for that, especially heavy wet snow. Each transmitter carries with it a self-monitoring device which verifies that the signals are being sent out within acceptable tolerances. When heavy, wet snow falls in front of the glidepath antenna, it affects the radiation of the radio signals being sent out, therefore altering the glidepath angle. If it's out by too much, the equipment fails itself. Good safety device, in that respect. But now the weather is still dirty and pilots have no ILS, just a localizer -- for as long as that holds.

GPS is an example of a type of navigation that doesn't rely on snow-covered antennas to deliver it's signals. The future for GPS in aviation certainly looks bright, especially with new satellites being launched that will transmit the same codes on two different frequencies for civilian use. A more accurate system stands to come from it, enhancing what is already a good thing. It's not too soon from an ATC standpoint to see an improvement to methods used to get aircraft where they want to be.

Saturday, January 15, 2005

Distance with DME vs (RNAV) GPS

When flying IFR, and you're asked to report a distance, make sure you comply with the request and use the proper phraseology. Miles are miles, right? Not quite.

ATC uses reports from aircraft in non-radar environments to determine spacing and applies restrictions based on standards to prove separation. In the old days, DME was the only real method of measuring distances. It was recognized, though, that DME distances are slant range. This means the distance from the aircraft to the facility, rather than the distance between the aircraft's latitude and longitude and the coordinates of the DME facility. Mind you, this difference is often small, but it is significant when you're higher up, closer to the facility, or both. For example, if you pass overhead a DME facility at FL240, you should read something on the order of 4.0 NM as you fly over (approximately 6,000 feet per NM, with some tolerance for errors).

RNAV in general, with the more recent addition of GPS to the term, has changed this. Now, instead of relying solely on DME (or at all, for that matter), many aircraft are capable of reporting distances in miles instead of DME. Problem is, certain circumstances require additional separation for DME to account for slant range and known DME errors that don't occur with GPS. Hence, if a pilot is asked for his DME from a facility, he should respond with a DME reading, rather than an along track distance derived from RNAV or GPS, stating his reading as "20 DME", for example. If the controller doesn't specify what he wants, the pilot should report his distance qualified with the word describing where it came from. If he reads his DME, the pilot should say, "20 DME." If he gets it from RNAV (including GPS), he should say, "20 miles". Kind of subtle, but it may very well make a difference.

Friday, January 14, 2005

ATC Joke

Pilots will love this, I'm sure. Heck, I do. I know it has nothing to do with aviation in Canada directly, but hey...

A woman was looking at the animals on display in a pet store. A man walked in and said to the shopkeeper "I'll take a Ramp Monkey, please." The shopkeeper nodded and took a monkey out of a cage. He put a collar and leash on the animal and handed it the man, saying, "That'll be $5,000." The man paid and left with the monkey.

The surprised woman went to the shopkeeper and said, "That was a very expensive monkey. Most of them are only a few hundred dollars. Why did that one cost so much?" The shopkeeper answered, "Ah, that's a Ramp Monkey. He can drive tractors, load cargo, and guide aircraft into gates. All with no back talk or complaints. He's well worth the money."

The woman then spotted a monkey in another cage. "That one's even more expensive! $10,000! What does it do?" "Oh, that one" replied the shopkeeper. "That's a "Flight Attendant Monkey. She's attractive and personable. She can serve drinks and meals, and even evacuate passengers from an aircraft in an emergency. A very useful monkey indeed."

The woman looked around a little longer and found a monkey with a $50,000 price tag. The shocked woman exclaimed, "This one costs more than all the others put together! What in the world can it do?"

"Well," said the shopkeeper, "I've never actually seen him do anything except drink beer and play with himself, but his papers say he's an Air Traffic Controller."

Thursday, January 13, 2005

IFR and Visual Passage

You're cruising along and want to get lower. When asked, ATC says "traffic 12 o'clock, 10 NM, opposite direction Dash 8 1,000 feet below. Expect lower once you pass." With radar, it's not all that inefficient, since as soon as we can see black screen between your targets, we can drop you. Non-radar (mind you, the traffic statement above would have been different, since he can't point out the traffic to you without radar) visual passage can be quite the help, since ATC has to prove you have passed with position reports. There is one key to using this effectively, though, from a pilotting perspective -- the pilot in your opposing aircraft.

To use this, both pilots have to report visual passage. More often than not, one pilot is keener than the other, and reports passage (often in advance of the passage itself). As ATC, I normally wait for a few seconds, hoping the other pilot reports same. By the time I were to ask the other pilot to confirm it, passage has taken place on radar and there would be little point. Non-radar, it can be much quicker to have both call, so I will solicit a passage report in that situation. "Aicraft123, a Dash 8 just reported passing you 1,000 feet above. Did you see him go by?"

So if you ever find yourself in a situation trying to use it, and ATC doesn't seem to act on your call, it may not be because he doesn't trust you -- he may be waiting for the other guy to make the same report.

Wednesday, January 12, 2005

Aircraft Accident Images

For some reason, ATC types seem to like looking at images of things going wrong on aircraft. Is that a bad thing? Come on, there's a little "rubberneck" in all of us, isn't there? Some things are just so ugly you have to look.


Here you'll find some images and videos, mostly related to aircraft accidents on the ground and in the air. Pretty interesting stuff.

Tuesday, January 11, 2005

GPS in Aviation

I attended a seminar last evening on GPS and aviation, hosted by the knowledgable George Dewar. He's a long time GPS wizard with a background of an inspector with Transport Canada since 1993 who moved to NavCanada to begin designing GPS approaches (with the first two stand-alone GPS approaches in Canada being RWYs 14 and 32 at Saint John, NB - CYSJ). He has been involved in outside projects as well, giving him a good base knowledge level and plenty of surveying experience.

The ILS is protected as the primary precision approach NAVAID by ICAO until 2010. After that, we're going to see some changes. First off, the current GPS platform is pretty darn accurate already, the issue is one more of integrity. With 30 satellites in orbit (GPS only requiring 21 for coverage), availability isn't a problem, either. But the concept of starting a GPS approach to CAT I ILS minima only to have it complain of poor satellite signal quality is not a good thing if all you have is GPS. Satellite health suddenly changing, geometry not working out, etc. All of these issues remain to be tested and proven, as some carriers are now in the process of doing. For this reason, GPS still is not classed as a "sole means" method of navigation for IFR flight.

Over the coming five years, GPS will find its way more and more into our flying lives, and eventually there will be no more ILS system installations. Newer avionics will be capable of handling enroute, terminal and approach phases of flight without the need for ground-based NAVAIDs. Of course, there will be many aircraft who don't have GPS, so current ILS systems will continue to be maintained for some time. Nobody needs to look for a new job just yet. The aviation industry has historically been quick to look at new ideas but slow to implement them and even slower to remove the old when it's obselete.

Monday, January 10, 2005

SID Busts

See if you can spot the difference between these two clearances:

"ATC clears Tartan 150 to the Toronto Pearson airport via the Halifax 3 departure, flight planned route, squawk 3101."
"ATC clears Tartan 150 to the Toronto Pearson airport via the Saint John 2 departure, flight planned route, squawk 3101."

The SID is the big difference, right? Wrong. Checking the SID plates, they are both worded the same way, "ALL RWYS: Climb runway heading for radar vectors, maintain 5,000 or as assigned." Care to guess again?

The big difference is that the Halifax 3 departure is rarely busted, and the Saint John 2 departure is frequently busted. For some reason, aircraft departing Saint John, Fredericton and Charlottetown depart frequently with SIDs from these airports and immediate make a turn on course and break through 5,000 in the climb. The persistent theory includes the fact that these airports are uncontrolled, but as mentioned in the previous posts, this only means no control tower in operation. There is still controlled airspace to the ground at these places. It is a mindset issue at these FSS-served airports? Pilots I've spoken with off the radio are at a loss to explain why this occurs. Other airports with SIDs which are not equipped with control towers don't seem to have the issue, either. Any thoughts? I'd love to hear them.

Saturday, January 08, 2005

Airframe Icing

In Microsoft's Flight Simulator, often the only sign of airframe icing is the airspeed dropping to zero. This is because your pitot tube is iced over, thereby meaning no dynamic pressure to provide a reading on the instrument. In real life, airframe icing can be much more drastic. This issue of the Aviation Safety Letter, published regularly with amendments to the AIP Canada, had a number of articles this time around about airframe icing, how quickly it can develop and how nasty it can get. A pilot of a PA-24 Commanche found out first hand as his airspeed dropped, his angle of attack increased as he tried to maintain altitude, all in time to enter a spin. Other stories in there pique one's interest as well, with a great, well written summary of things to look for before flying to help you avoid it. Of course, if you're in a Dash 8 or something that can handle a lot of icing, it's a different story. But when your only de-icing or anti-icing gear is a pitot heater, you have to stay on top of your winter flying game.

The Aviation Safety Letter is published every 2nd publication cycle (every 16 weeks) and is archived at Transport Canada's website. This month's issue is not yet available here, but it should come out soon. One can learn a lot from the mistakes of others. Here is link for back issues to provide interesting reading:


Friday, January 07, 2005

Uncontrolled Airports vs Uncontrolled Airspace

A comment from my last post was related to most uncontrolled airports in Canada being in uncontrolled airspace. This is true, but has little to do with the fact that the airports are uncontrolled. The reasons different classes of airspace are established are related to traffic flow and desired levels of service within them.

In the case of many uncontrolled airports (like those with three-letter-one-number designators), many just don't have the level of IFR traffic to warrant any extra precautions. With this level of traffic, most aerodromes have an ATF, or Aerodrome Traffic Frequency, established. These are treated just like Mandatory Frequencies (MF), but aircraft without radios are allowed in them. If IFR traffic were to frequent the airports to the point where IFR-VFR conflicts became an issue, the airspace in the area may end up being reclassified as Class E controlled airspace to raise the weather limits for VFR flight, thereby giving a better shot at letting the see-and-be-seen concept work. This would also mean separation would now have to be provided between IFR aircraft. Were an airport to become busier yet, a control zone may be established to once again ensure higher weather limits are necessary for VFR flight now around the airport itself, instead of just the area around it. A CZ is controlled airspace from the ground up to a defined height, which probably enters the base of surrounding controlled airspace. Note that a CZ in place doesn't necessarily mean that an airport control tower is in place. At this point, we have a CZ with controlled airspace to the ground, but it's likely Class E, which permits VFR without talking to ATC, but IFR need a clearance. A Class E control zone normally has a Mandatory Frequency assigned to it, and often has a Flight Service Station established, either on site or for RAAS (Remote Aerodrome Advisory Service by RCO). Again, another increase in traffic might warrant the establishment of a tower, and now the CZ would likely get a designation of Class D, meaning airport ATC has authority in the airspace and VFR must contact ATC to enter.

An airport with a lot of VFR-VFR could also meet requirements for a tower to be established, even without the IFR traffic. This is somewhat more rare, but it does happen. These areas are often already surrounded by controlled airspace, since it would happen in areas which are already busy with other traffic.

This is why so many of our uncontrolled airports are in uncontrolled airspace. The traffic levels just aren't there to require it. Uncontrolled airports and uncontrolled airspace are sort of disconnected. A controlled airport always means controlled airspace, but controlled airspace doesn't always mean a controlled airport.

All of the classificiation of airspace can be found in the Desingated Airspace Handbook (DAH), which is downloadable from http://aero.nrcan.gc.ca/english/ATS_dah_e.html, and the Canada Flight Supplement has information on individual airports and their facilities.

Thursday, January 06, 2005

Mandatory Frequency Calls for IFR Arrivals

Have you been given a "reminder" by ATC while approaching an uncontrolled aerodrome to make mandatory frequency calls? Have you been annoyed by this? So is ATC, generally speaking. In the Moncton FIR a couple of years ago, a few pilots failed to make these call, and blamed it on ATC when questioned about it. As a result, we received direction to "instruct pilots to make mandatory frequency calls as required." I think most pilots either like the reminder or ignore us and make them, since the complaints seem to have stopped. Several pilots complained to us, and rightly so in my opinion, when this direction came out and we started doing it, since, as one pilot reminded me, "That's why they call them mandatory frequencies." I couldn't agree more.

The fact that a pilot is operating on an IFR clearance and talking to ATC doesn't remove his responsibility for making mandatory frequency calls while approaching an uncontrolled airport. With a tower in place, there is no such requirement. ATC nomrally coordinates as required behind the scenes to ensure safety. With a mandatory frequency, there is no control agency, and thus the requirements have been instituted in the Canadian Aviation Regulations (CARs) regarding the mandatory calls. The one that some pilots miss is the one that would have you make a report with position and intentions, "5 minutes prior to commencing an approach." If you have a second radio with which to make them, this is the preferred method so you can still monitor the ACC or TCU while in flight. If you only have one radio, remember to advise ATC prior to leaving his frequency that you must do so to make these calls. This way, ATC knows you'll be out of radio contact briefly and can plan accordingly. Many of us these days try to clear aircraft for approaches early and get them over to the MF so they don't have to issue these reminders -- the aircraft are already on the MF.

Wednesday, January 05, 2005

Canadian Aviation Publications

A man I have great respect for as an airspace designer and planner, Mr. Neil Shea, has set up his own consulting firm. I hope he doesn't start charging me, since I have often asked him questions out of my own curiousity, and to seek answers for others. His experience includes many hours on several different aircraft types in some of the worst weather conditions in Canada (St. John's, NF, among other places), and a position as an airspace designer for airways and approaches with NavCanada for several years. He found my blog, and has offered his services for anyone who has questions about publications in Canada, more specifically those related to approach and enroute charts as opposed to rules and so forth. Got any questions? His site address is:


Feel free to check it out.

Frequency Changes

Anyone who has read my "Topic of the Week" series that I wrote over 2003/2004 knows this is a pet peave of mine. When ATC or another communication agency instructs a pilot to change frequency, it really bothers me when a pilot doesn't acknowledge. It happened several times at work last night. All that is needed is a simple, "See ya," or something to let me know you heard me. If I don't hear that, I have to say it again. Then again. Then I have to call the other guy and see if you checked in. Some have asked, "Why? What does it matter?" Well, unless you'd like a Dash 8 or a Cessna as a hood ornament, I have to know that you heard the frequency change and are with the right controller so if he has traffic for you, he can get a hold of you. It's awfully tough to provide ATC services to aircraft you can't communicate with. I've had several situations where I've called an aircraft three or four times, only to find out he was actually still with me, and was otherwise occupied in the cockpit. Imagine if I had just assumed he received the frequency change. Eventually he drifts out of VHF radio range and now the workload in trying to get a hold of him quadruples. I have to try to relay through other aircraft, maybe call company and get them to try contacting him. It's a little thing that can turn to a big thing totally unnecessarily. Just say, "Bubbye!" or something, and I'll know you are where you should be.

Tuesday, January 04, 2005

FMS Arrivals - Top of Descent

Watching several Air Canada Airbuses (Airbi?) descend into Halifax, NS (CYHZ), I started to wonder why some of these aircraft, all FMS-driven on the same inbound route and FMS STAR, all seemed to start descent at vastly different points and at vastly different rates of descent. I was comparing primarily A320 with A320, though the similarities with the A319 and A321 came into play as well. Some start down early and descend slowly, while others hang up forever and then dump. I took the opportunity that presented itself one midnight shift to ask a pilot when he was the only one on that particular frequency (we work many from one position through the night).

He told me that the FMS will generate a profile based largely on weight, which will affect TOD and descent rate. Makes sense. He also said that when the FMS generates its plan, the pilots can push taht back or forward to stay up high out of low level turbulence, icing, etc, a little longer, or start down earlier for traffic or whatever. Then, they mentioned the minor differences between the A319, A320 and A321. Then another voice, obviously the other guy at the helm, said, "And besides, we're in an A321 and they can be a real prick to slow down, so we started down early." A good point, though put a little bluntly.

Monday, January 03, 2005

"Violated Airspace"

After my previous post, I received a question about the term "violating airspace", and the context, if you didn't read it, was busting an IFR clearance. Actually, that's the term we use in Moncton ACC for an aircraft that climbs through an altitude, or turns on take-off when runway heading was assigned, etc. He "busted his clearance," or, "broke his clearance". Before I had read all of his question, I immediately thought of entering restricted airspace, or a VFR entering Class B, C or D airspace without contacting ATC. Can anyone else offer any insight on this term and whether "violating airspace" is a common phrase outside my little world?

Sunday, January 02, 2005

High Winds & Turbulence

Going flying? Would you like a smooth ride? Did you notice the winds outside as you drove to the airport? If they're strong on the surface, you can bet they're strong aloft and probably not lose. Want another sure bet? Bumps in the lower levels.

Mechanical turbulence is its name. When the wind cruises along and hits trees, hills, even buildings, it gets churned up. Especially if it hits a small range of hills or cliffs. The wind has nowhere to go but up, where it disturbs the winds in the levels above it. All of this creates turbulence. 20 knots (~40km/h) of wind on the surface is good for moderate turbulence up to 3,000 or so above ground level, even in relatively flat terrain.

Now look at a real mountain range like the Rockies. If the winds are strong enough, you can get the Mountain Wave effect. When this happens, you can get little bubbles of air caught between wind levels, creating a strong rolling effect. These can be very dangerous for light aircraft, producing a rolling moment strong enough that the aircraft can't counter, thereby leading to an uncontrolled flip. Even airliners would do well to avoid them, if only for a smoother ride. Sometimes clouds will form in the bubbles, and these will help you avoid them. If the winds are strong enough, they can persist for several tens of miles, even a hundred or so, downrange from the mountains. Stay away from these areas when it's windy.

Saturday, January 01, 2005

Outbound Reports

Picture this: You're holding on the Final Approach Fix for runway 27 at some airport. You're inbound track is, of course, 270°, and over the FAF you make the right turn (of about 180° as per my last post regarding holds), fly that heading for a minute (or 1.5 minutes, depending on altitude), then make the turn to rejoin the final approach course inbound to the FAF, at which point you repeat the whole process. Answer this: At what point are you "outbound" in the hold?

I can't speak for other countries, but for Canada, it's clear in the AIP, RAC 9.14. You're outbound when you're over or abeam the holding fix and heading away from the airport. This means that if you're on the final approach course and cross over the FAF, you're not outbound yet. When you complete the turn to the reciprocal of the inbound course and you have passed the FAF, only then are you actually outbound. It seems many pilots believe they are outbound when they are over the FAF and commencing the turn to the outbound leg. The same point applies to an aircraft cleared for an approach with a procedure turn.

Why is this important? If ATC clears you for an approach and says, "...not below 4,000 til by the Sumspot NDB outbound,", he's probably setting up for a departure to come out the airport you're approaching, and he probably has the departure cleared off with a restriction at 3,000 feet. If you were to hit the FAF and commence your descent from 4,000 while you're still pointing at the airport -- thinking you're outbound at that point -- the departure restriction at 3,000 feet would be meaningless, and separation would no longer be a sure thing. It's by proving "tail to tail" that separation is accomplished. In our example above, the airport is west of the FAF and the departure is proceeding away from the FAF. You're by the FAF eastbound and proceeding away from the airport. This is cold, hard proof that there is separation between you and the departure.