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I know this isn't exactly an ATC topic, but I want to express my feelings for the firefighters that died the recent Saskatchewan plane crash. I've always respected firefighters in general, and more specifically the aviators who fight these blazes. Having had the opportunity to watch these folks fly some missions from the ATC point of view (coordinating their activities with those of other traffic from both the tower and ACC points of view), and even watching them as a spectator. Some of the conditions they fly in, be it the smoke and fire, and the resulting air currents as they make their way, or the sites from which they draw their water, and just the coordination of their own flight paths to and from the busy airspaces, make their jobs very dangerous. Their skills as pilots and firefighters are tested daily in their missions, long hours included. It's amazing the amount of professionalism that goes into every flight. The fact that there aren't more accidents in the line of duty proves their worth as airmen.

I hope their families can accept what has happened and move on, knowing that the efforts, even if underappreciated by many, were very important to the rest of us as a whole.

In a non-radar environment, ATC will often issue restrictions on flight to IFR aircraft to help them prove that they have separation. These restrictions may include statements like, "Cross the Sumspot NDB outbound at 4,000 or above," or, "not above 6,000 til 20 DME." Sometimes we assign an aircraft a "radial climb" from a VOR or VOR/DME facility. Using this method, ATC is assigning the radials to ensure a form of lateral separation exists between aircraft when vertical doesn't. Would you understand a clearance and what's expected of you?

Pretend, for a moment, that you're a pilot sitting on the ground at Dumbplace airport with a VOR/DME facility on the field. You call for IFR clearance to Coolplace on a route that takes you over Anyplace VOR and then onwards, all of this in a northwesterly direction. ATC's clearance for you comes over something like this: "ATC clears Foxtrot Alpha Tango to the Coolplace Airport via direct Anyplace, fight plan route, maintain one four thousand. Depart runway 36, make climb from four thousand to one zero thousand established on the Dumbplace three three zero radial, not above four thousand til seventeen DME." Now let's look at the clearance.

The final assigned altitude is 14,000. But in the climb to 14,000, there are two restrictions. We're told in the clearance to depart runway 36, but nothing else for that departure. This means that ATC really doesn't care what we need to do immediately after departure, and is not restricting us to runway heading or anything specific right then. But there are two conditions that we must meet before we climb above 4,000. We have to pick up the 330R and track it outbound, and we can't climb above 4,000 until we're established on it outbound -- not just when we see needle deflection, but actually on it outbound. Then we have to make sure we don't go above 4,000 until we're beyond 17 DME from the Dumbplace VOR/DME. After departure, we must chose how to manoeuver to reach and set up on the 330R outbound, and even if we're on the 330R before 17DME, we must stay at or below 4,000 until we reach that distance (and, BTW, since DME was specified in the clearance, use of GPS is not allowed for this measurement -- DME must be used when specifically asked for by ATC). Once we reach 17DME, we must continue to track the 330R outbound as we climb until we reach the high end of the restriction at 10,000 feet. What next? We head out on the assigned route of flight, which was, "direct Anyplace, flight plan route." Upon reaching 10,000, we can turn and fly directly to the Anyplace VOR from wherever we are at that moment and proceed on course.

Such a clearance would be issued to allow you to depart and climb to flight planned altitude (or something close to it) and provide ATC with some kind of separation. You could deduce from this clearance that there is another aircraft out there, and likely assigned a radial that is at least 15° off yours (so inbound on the 345R or further clockwise, or the 315R or further counter-clockwise). Note the altitude range in the radial climb assigned to you? This means the other aircraft has probably been cleared on a radial descent (or will be in the near future) to go from 9,000 to 5,000. This keeps you laterally separated by assigned radials, from the moment the controller has given up vertical separation until you are vertically separated again. In all likelihood, these restrictions will change a little once you get airborne. The two most likely ways this would happen are if you climb above the other traffic before you reach 10,000 (because he has descended below 9,000 already), or if you two pass while on the radial climb/descent and DME reports show you at least 5DME apart. The specifics would depend on the situation, but in many cases, the restrictions may end up being broken early by ATC.

So the next time you hear "descend to 6,000 on the 270R", will you understand what's expected of you?

Sometimes I love technology. And new products coming out for aviators and aviation enthusiasts can be very interesting, indeed.

Recently, a company in the US began building a relatively cheap device that functions like TCAS, meant for use in the cockpit. It measures aircraft transponder replies and shows the pilot visually, kind of like a radar detector in a car, how close another airplane may be, as well as with an audible alarm in one's headset (if the headset is plugged into it like a throughput connect, since it can then plug into the radio jack itself after that to forward radio audio from the normal channels). The system doesn't detect directional data, only range, so it will only warn you of an aircraft being within a preset distance. Interesting, if not all that useful. As long as someone doesn't forget to turn the thing off in the circuit...

For those who fly their desktop and want a little more information, there is now the Virtual Radar for the PC. An antenna and a box that communicate with your computer can now show Mode S transponder returns and the data they send, allowing for updated information including position, speed, altitude, etc, of aircraft in your area. This system is passive, so it just sits and listens for the info. While airliners may be visible, the average C172 still doesn't have Mode S on board, so the little bugsmashers won't be visible to you with such detail (if at all), but you can still watch those high flyers over your neighbourhood on a screen that is purported to be "ATC-Like" as a display. All of this for just under $1,000, too. I have to admit that as silly as I think this is, it's awfully interesting to me...

I didn't put any links up, since I don't want to seem like I'm advertising their products. I'm writing more about the abilities of technology that's out there, not trying to support a manufacturer.

What will they think of next?

In a similar vein to my previous post (pilot requesting contact approach to one runway, circling for another), I fielded a request last evening which made me wonder...

A pilot in a neighbouring sector approaching an airport in mine, was offered a direct routing to an IF for one of the approaches at destination. The pilot, properly, refused, saying, "We're unable that. We have no RNAV this evening." Not a problem, continue last assigned routing. The flight entered my airspace later, and was offered the weather. The pilot said he had that weather, and then asked for, "...a heading until able direct FIXXA." To protect the identities, the name has been changed, but FIXXA was the IF originally offered to the pilot. Since he had refused it on the grounds of no RNAV, this request threw me off a little. If he wasn't able direct FIXXA right now, how would the heading help him? When would he able direct FIXXA? I'll offer such assistance if the fix in question is something the pilot will be able to navigate to in the near future. For example, he's setting himself up for an approach based on a low power NDB that he is not yet receiving, or a VOR that is just out of range that he'll pick up shortly. "Fly heading 270 until able direct the Sumspot NDB." But a point in space, that he'll never be able to find on his own? That request seems just a little strange to me. In the end, I asked him again if he was able direct FIXXA, to which he confirmed he was not. So, believing what he really wanted was a vector to final, I offered him that and he accepted. The night carried on fine from there.

I was left wondering. Is this simply a case of not clearly communicating what was desired? That's my guess. But whenever something like this happens, I find myself wondering if I was missing something. Any thoughts on what I was missing, or do readers also believe it was simply a miscommunication?

More often lately, pilots requesting Contact Approaches to our outlying fields in the Moncton FIR are making a request that seems a little strange to me. For example, the winds are out of the northwest, and an aircraft is inbound from the west. The weather sequence shows weather fine enough for a visual. It sometimes seems strange when offered a visual approach that a pilot will refuse and ask for a contact approach instead, but that's another issue. There are a few pilots who will ask specifically, for examlpe at CYFC, a "contact approach to runway 09, circling for 33".

I don't know where this sort of request comes from. From an ATC viewpoint, whether you do a contact approach to 33 from the west or a contact approach to 09 from the west, it's all the same. Except, of course, that you're likely to take another minute or so to fly to runway 33 from the west while you fly downwind an what not. I don't know why a pilot would ask to fly a contact approach to 09 and circle for 33, since to me, this would essentially be a contact approach to runway 33, in the end.

Anyone have any thoughts on the logic behind this sort of request?

It is often the case when flying IFR into low density airports that a pilot will receive a clearance something like, "Cleared to the Sumspot Airport for an approach". These non-specific approach clearances are meant to accomplish a couple of things: Save a few words, and allow the pilot to do an approach of his choice. There are some rules, though.

First things, first. Pilots are expected to inform ATC of the approach they plan to do. And also, according to the AIM, RAC 9.3, once the pilot has advised ATC of the planned approach procedure, he shall not deviate from it unless prior approval from ATC has been received. Equally important, a pilot in receipt of such a clearance is responsible for terrain clearance. For example, an off-airway route to an IF for a straight-in procedure will require attention to minimum IFR altitudes to ensure the aircraft is operated at safe altitudes. This can be done by verifying that the aircraft is within 25NM of the FAF for quadrantal altitudes, for example, or by reference to LO charts for Geographical Area Safe Altitudes (GASAs) if the aircraft is still far enough away from the airport that none of the closer altitudes will cover it.

Once in receipt of a non-specific approach clearance, the pilot may proceed to any fix associated with the chosen procedure, and may do so via any desired route. An important aspect of the unrestricted approach clearance is that a pilot is responsible for remaining clear of restricted airspaces. A perfect example of such a problem is at CYSJ. Many aircraft flying to CYSJ, Saint John, NB, approach from the northwest. Into this airport from this direction, the airways will keep an aircraft clear of CYR724, a restricted area with live firing up to FL250. If an aircraft receives a non-specific approach clearance, and then chooses to navigate to the IF for runway 23, the route could very well take him through the south end of CYR724. Situational awareness comes in handy, as do the enroute charts for determining if there are any such issues to contend with while transitioning from the enroute to the approach phase of flight.

Lastly, the non-specific approach clearance does not allow a pilot to do a contact approach, or a visual approach. The approaches allowed under this provision are published instrument approach procedures. Technically, the visual and contact approaches are both "IFR approaches" but neither of them are "instrument approaches", and therefore are not permissible. If a pilot wishes to do a visual or contact approach when in receipt of such a clearance, typically all they need to do is ask for the approval, and in most cases, it will be allowed. The unrestricted approach clearance is issued because there are no other aircraft in the area to conflict with, so a visual or contact approach would do just fine from the ATC point of view. If there were other aircraft involved, the pilot wouldn't likely receive a non-specific approach clearance in the first place.

So "unrestricted" doesn't mean completely unrestricted in the sense that there are some rules to adhere to. But the choice of instrument approach procedure and the route of flight are both up to the pilot. Just keep alert while descending.

A question I field fairly frequently relates to altimeter settings and whether they should be read back to ATC when issued. The short answer (if you can believe I'm capable of giving a short answer) is, "No." I haven't yet found anything written anywhere that makes it mandatory to read back an altimeter setting, whether IFR or VFR, when talking to ATC, FSS, Unicom, or any other agency. Do I believe it should be done? Yes, absolutely.

OK, I did it. Now here's my long answer...

I've seen and heard about a few situations that may have been averted if the altimeter were readback. Once, not all that long ago, an aircraft being vectored downwind at CYSJ, fortunately descending over water, seemed to be dropping pretty quickly considering he was about to reach his last assigned altitude. When querried, the pilot confirmed he was descending to the correct altitude (though neither the controller nor the pilot verified the current altitude). When issued the altimeter setting again to verify, the pilot sharply replied that he had set the altimeter 1 inch off (3025, rather than the actual 2925, for example), meaning he was out of 2,400 when he was showing out of 3,400. This could have turned out quite badly had the aircraft been vectored on the other side of the field. In the subsequent tape check, the altitude issued by ATC and read back by the pilot was correct. The altimeter setting issued by ATC was correct, but the pilot admitted to setting the wrong one by accident. If it were read back, a matter of a second on the radio, it may have been caught.

While there is no requirement to read one back, I would estimate that at least 99% of pilots do read them back anyway. And when they do, as a controller, I will listen to altimeter readbacks as diligently as I listen to readbacks of altitude assignments that accompany them. Pilots don't often make mistakes with this, but every now and then one will slip in there. Heck, I've even caught it myself when a pilot correctly reads back the altimeter setting that I issued, only to notice that I issued the wrong one. Once again, something only happens once in a blue moon, but mistakes can be made. It's a cheap and easy security blanket, in my opinion, and the risks (the extra second or so of radio time) versus the benefits (given the potential dangers of an incorrectly set one) make it well worth the investment of time.

I received an e-mail recently that my old "Weekly Topics" site gave rise to. The originator of the e-mail is an aviation enthusiast much like myself, but had a more interesting way of sharing his experiences -- an interactive one. He has used MacroMedia's Flash browser plugin to build some interactive flight training aids, including things like altimeters (simply reading them, as well as cold weather altimeter errors), using VOR gauges, HSIs, and so on. The site is well put together, and interesting for those who don't know yet how to read some of these gauges. Anyway, the URL is:

http://www.luizmonteiro.com/

Have a look over the entire site, but most specifically, look for the orange button labeled "Learning & Tutorials".