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The other day, we had a US military C130 flying through the Moncton FIR. About halfway across the region, the aircraft was unresponsive to a frequency change when leaving one sector for another. We tried to get a hold of the aircraft through various sources, but could not get a response.

Then, a call on 121.5 was made, and while no radio answer was received, the aircraft's target began to flash on radar. It seemed hardly a coincidence, so we went with the possibilty of RONLY -- the aircraft could not transmit, but could receive. A few attempts to ask the aircraft to tune another frequency to carry on communications in the same fashion failed, but we eventually raised the aircraft on UHF through this method of one-way communication over 121.5.

This got me thinking about abnormal communication methods, where we consider "normal" being two-way radio communication by voice. In the ATC-Pilot world, there are other options, these days. Many airlines, including some regional airlines, have data link capability. For example, a Jazz pilot informed me recently that almost all of their aircraft, if not all, were capable of sending messages through their data link system from one aircraft to another. This is useful information, since on occasion an aircraft is lost to VHF communication as he flies away from a transmitter site, but is still well over the civilized world. We could ask another flight, perhaps one that is not even in communications range through normal VHF, to send a message with the next ATC frequency to use. Highly useful as a backup form of communication, from my perspective.

The squawking ident that the C130 used was a good idea, too. When this feature is activated on a transponder, it makes the radar target's appearance change. On Canadian screens, the target turns white and flashes, something that will obviously catch the eye of a controller. It's not always clear that this is meant as a form of communication, since there are various ATC units from ACCs and towers with radar, as well as FSS who have radar screens. Trying to make this a meaningful method of communication may not be as easy without some other useful context as that described above. We're calling you, can't get an answer on the radio, but every time we call you, your target flashes. Coincidence? I think not.

Then there are the old-style methods still depicted in the AIM: The radar triangles. I can safely say that most pilots I know are only vageuly aware of this concept at best, and I have never observed one on radar. Nor have I heard of any stories where these have been used in a practical environment in my 15 years in ATC and 18 years of flying. In fact, most people I have encountered who are even aware they exist would have no idea for sure which to fly to communicate which situation. Is it left hand or right hand to communicate radio failure? And how long were the legs again?

Anyway, with the advent of cell phones, satellite phones, and many pilots flying with handheld backup tranceivers, communications failures are, very happily, becoming rarer and rarer. When I fly, I even bring a backup handheld receiver with me, so I should be able to at least hear what others are saying even if I can't respond directly. Still, comm failures happen from time to time. It's a good idea, given the ever increasing importance of communication in the skies, to have a backup plan. What's yours?

Recently, while working at Moncton ACC, I received a phone call from Halifax FIC. The call was merely to relay the closure of an IFR flight plan for an aircraft that had landed at CZBF, Bathurst, NB (actually in Quebec FIC's area). This phone call surprised me, since I didn't even know the airplane was airborne, yet. How is it possible, you might ask? Here's the set up.

The flight plan was for a PA31 Navajo departing Bonaventure, QC (CYVB), and landing CZBF, a total distance of about 30 miles. The entire flight is below the base of controlled airspace, which in this area is "above 12,500 ASL", meaning that you could fly at 12,500 and not be considered in controlled airspace. As such, the pilot does not require an IFR clearance to fly in IMC on his IFR flight plan. He or she is free, legally, to take-off, fly the entire leg and land without direct contact with ATC.

Regular readers of this section have probably seen similar posts on this topic from me in the past. Did the pilot do anything wrong, here? The only thing missing was the departure message. Pilots on IFR flight plans of a similar nature (entirely outside controlled airspace) are still required to file a departure message and an arrival message. This means contact must be made with Air Traffic Services (ATS) after take-off to let them know that you took off safely rather than piling into the trees on take-off, and to open the IFR flight plan for the sake of alerting services at destination, and along the route of flight. The pilot must also, at some point, close the flight plan by filing an arrival message or speaking those very magic words, "close the IFR flight plan". Remembering that "canceling IFR" is not the same as closing the flight plan in Canada.

So if an IFR clearance is not required, why make the call about the departure message? Well, at my "data board", I was holding the proposed flight plan, and considered it inactive, meaning the aircraft was not airborne and enroute. While CZBF is in uncontrolled airspace, there are other flights that fly in and out of that airport who do enter Class B and E airspace nearby, and therefore do call for clearance. When they do, we look at known traffic in the area and issue this with the IFR clearance to help the pilot know the traffic picture. "ATC clears Alpha Bravo Charlie to the ... squawk 3101. Traffic is a Navajo proceeding from Bonaventure to Bathurst, reported at 4,000 IFR, estimated Bathurst at 1535." Similarly, if the inbound to Bathurst were to call us, we could report that there was someone on the ground at Bathurst who called for IFR clearance and anticipated being airborne at a certain time.

In any case, it is believed now, after looking into it, that the pilot had considered something else. The flight is very short duration, just a little more than 10 minutes in the type of aircraft involved. ATC waits 60 minutes after the proposed time of departure (ETD) for a departure message, and then we go looking for the aircraft, following the assumption that the pilot tried to take-off and failed, and might be in need of emergency assistance. The 60 minutes is to allow for communication difficulties after a safe take-off, and to allow some room to wiggle without alerting emergency services in every instance since it is rare that the actual time of departure is right on the proposed time. The pilot may have, in this case, regarded the arrival message as being sufficient to both activate the flight plan and close it at destination, since he knew we'd be looking for him before he landed, anyway. I suppose this could be argued successfully, too, as being somewhat safe, but it meant that two control agencies (Montreal ACC and Moncton ACC) were not aware the IFR flight had taken off.

As a controller, I'd have appreciated knowing he was enroute. Knowing, after the fact, that no harm was done, is this legitimate? The pilot really should have filed a departure message out of Bonaventure, even for such a short flight.

Something I haven't seen in a while but was reminded of recently involves the flying of DME arcs established for transitions to straight-in instrument approaches. In the Moncton FIR, we have a few military units that do "round robin" flights for IFR currency and training, as well as a few civilian schools up to the same activities. As part of this, DME arcs come into the flights sometimes for practice. The issue I raise today springs forth from these flights, though someone intending a full-stop landing after an approach could find themselves in a similar situation if radar vectors to final weren't available and this transition were chosen or assigned by ATC. Here's the setup:

ATC: "Alpha Bravo Charlie, you're number two at Saint John. What approach do you want to do?"
ABC: "Alpha Bravo Charlie, we'll take the straight-in ILS ruwnay 23 via the 10 DME ARC."
ATC: "Alpha Bravo Charlie cleared to the Saint John NDB via your inbound radial, the 10 DME arc and the localizer. No delay expected."
ABC: "Alpha Bravo Charlie cleared to the Saint John NDB via your inbound radial, the 10 DME arc and the localizer. No delay expected."

Sometimes what we see is the pilot reaching the 10 DME arc and beginning a descent. Apparently it's common for a pilot cleared to fly a DME arc to believe he may descend to the published altitudes on the arc, despite having no explicit descent clearance from ATC. In the previous example, the clearance to fly the arc provides the pilot with a new clearance limit and a new route, but no descent is issued as part of the clearance. This means the pilot is still required to fly his last assigned altitude.

The altitudes published on the arcs are minimum IFR altitudes for the approach segment. Unless issued a lower altitude as part of the clearance, the pilot is not cleared for descent. If the pilot were issued an approach clearance ("... cleared to the Saint John airport for the straight-in ILS runway 23 approach via the 10 DME arc."), he has authorization to descend. He may now, while on the airway before the arc, descend to the MEA at any time he wants, intercept the arc and descend to the arc segment altitude published as he sees fit. But unless a lower altitude or approach clearance has been issued and accepted, the pilot cleared to fly a DME arc is not authorized to fly anything but his last assigned altitude.

It comes down to understanding what's allowed as part of an IFR clearance. Sometimes, I'm sure, it's a busy cockpit and something seemingly small gets overlooked. But from the ATC side, sometimes very small can become very, very large very quickly.

Going hand-in-hand with my SVFR topics lately, I was recently reminded of another story that happened just a few years ago. I respect a lot of the guys I work with, but few of them as much as I respect the individual, now retired, involved in this story.

CYAW is Shearwater, NS. It is a military base that has been scaled back from a large air base to a helo base, and fixed wing operations no longer take place at that airfield. At the time of this story, there was still an active flying club. While most of their flying was done in the day time, this particular story happened at night, at a time when the control tower was closed for the night. Traffic at the time of the situation was very light throughout the lower levels of the FIR, which was probably a good thing.

The controller was working the low level airspace, which included the Halifax TCA, the airspace containing Halifax International (CYHZ) and CYAW. Out of the radio silence came a call from one of the Shearwater flying club's airplanes. As the controller listened, he watched a lone target in the vicinity of CYAW, likely doing some night circuits. The pilot asked what we were showing for weather at CYAW. This controller, a old hand who worked at airports such as CYHZ and CYYT, notorious for nasty weather like dense fog, immediately moved his mind to this sort of situation. The weather sequence at the time showed 1,200 scattered with an 8SM visibility. He read the sequence and the pilot acknowledged and thanked him for it.

I believe many people would have left it at that. Not this guy. He had seen a few too many problems. He kept the pilot on the radio, asked him what the weather was like as he saw it. The pilot described what he viewed as an undercast situation. There appeared to be a low-lying layer of cloud. My friend suggested that the pilot consider going to CYHZ, merely 15NM north, where the weather was still clear, after confirming that with the tower there.

The pilot stated that he believed he saw a hole in the cloud and he planned to descend through it to land at CYAW. Thinking about this, I shudder. If he's in the ciruit, and the cloud is below him, what odds does that give him that it is high enough to get under without being too low? I learned to fly at Shearwater and had many a flight fogged out between the time I left my house and the time I arrived at the base. Rapidly rolling fog is a matter of course at many oceanside cities, and Halifax is certainly in that group. My controller friend knew this all too well.

He suggested again that the pilot fly to CYHZ and land for the night. The pilot, again, refused, saying he figured he'd be OK there. Again, I think many controllers would have simply let the pilot go at this point, figuring they've done all they could. Not this guy. He pushed, gently, again to get the pilot to fly to CYHZ. The pilot relented and turned north. 2 minutes later, a weather special was issued for CYAW: 100 overcast, visibility 1/4SM in fog.

The pilot landed safely at CYHZ, and not even 5 minutes after that, the controller noticed the RVR values at CYHZ were dropping. He asked the tower about the weather, and the tower controller told him that the wall of fog was very visible, even in the dark night sky, as it rolled in, and within minutes the weather there was very much the same as CYAW, showing RVRs at 800 feet.

It makes me wonder how this situation would have played out if the pilot didn't call ATC to ask about the weather. Or if the controller let the pilot go as he refused to take the suggestion to land at CYHZ. Things could have been very different. One more reason I have the respect that I have for this man, and others like him with the wealth of experience under their belts. Hopefully, experiences the rest of us can learn from.

Most pilots cooperate very well with ATC. Sometimes ATC gives an instruction that a pilot doesn't really want to comply with. And sometimes the pilot may believe he has an alternative course of action and may make an offer to ATC to "help out". Sometimes this works, sometimes it doesn't. To demonstrate the down side, I'd like to share something that happened in my airspace a few years back.

The setup was a common one at the time: A Dash 8 climbing to FL230 ahead of a Beech 1900 climbing to FL210. Those familiar with the aircraft types will realize immediately that this setup isn't great. The B1900 will outrun and outclimb a Dash 8-100 almost every time. The route concerned was between Halifax, NS (CYHZ), and Deer Lake, NL (CYDF), a track of about 063°, and both aircraft were established pretty much right on the centerline, with the Dash about 25NM ahead of the Beech when I took the hand-offs.

As the aircraft climbed, I was fortunate enough to have plenty of time to pay close attention. With this in mind, I chose to watch it develop, hoping the Dash would climb through FL220 before the Beech got too close. Well, it didn't work that way. With only 8NM between the aircraft and a 20 knot overtake by the Beech, I decided to take a new course of action. It was time to vector the B1900. It became very apparent that the Beech was aware of the traffic situation, too.

The conversation went something like this:

ATC: "Airline 123, turn right thirty degrees, vectors for traffic."
Pilot: "Uh, we could take FL230 if it would help."
ATC: "Negative, the Dash 8 is climb to FL230. I need you to turn right thirty degrees, now."
Pilot: "Would it help if we slowed our climb rate?"
ATC: "No, that would just make you overtake him more quickly and I'm already running out of room. Turn right thirty degrees now."
Pilot: "Is there anything else we could do to avoid the turn? We'd really like to stay on course."
ATC: "Negative! turn right thirty degrees -- NOW"
Pilot: "Ok, thirty degrees right. New heading will be zero six six."

OK. I'm not a mathematical genius, and I don't know what the winds were. But I'm pretty sure that to get a track of 063°, a thirty degree right turn should not result in a new heading of 066°.

ATC: "In that case, make the heading zero niner zero, and you better be turning now."

As I said, this whole exchange started when I had 8 miles between them. By the time the bickering was done and the pilot took the final turn, I had 5.2 miles between them. It would have been considered a loss of separation if they ended up less than 5 miles apart.

Fortunately, most pilots won't behave like this. In my experience, most pilots, seeing the traffic on TCAS in front of them, would have accepted the turn, then asked about options. This pilot let a fair amount of time elapse before he finally took the turn, and it almost caused me some paperwork. Usually when ATC issues a vector for traffic, they need the turn to be started with little or no delay. Otherwise, someone's going to have a bad day.

The subject line of this post says it all. Let me elaborate on why I'm concerned for both sides of the radio.

When I began flying, there were a lot of airplanes around which still only had a basic autopilot. Even so, a lot of tasks were done by hand, including fuel management, navigation (Ok, the AP may have tracked the VOR radial, but the pilot had to keep on top of the navigation picture to know where he was an how to get the AP to do what he wanted the airplane to do), and other tasks associated with flight.

These days, more and more aircraft are becoming automated. Newer generation aircraft have FMS to manage the flight path automatically, digital systems to control engines at various phases, radio systems to enter flight data such as weight and balance, air data computers to do calculations associated with flying and navigation and so on. Pilots can sit back and watch over the systems and simply wait for alerts that something isn't quite what they expected.

I see two problems with this, and not just from an ATC standpoint. The more the computer does for you, the less likely a mathematical error may creep in, but the more likely a human is to become complacent as he/she learns to trust the computer. "Hey, it worked all those other times, why shouldn't it work now?" If something unexpected does arise, there may be a longer period of transitioning from audience to actor. Also, the less practice one gets at any given task, the less likely a person is to act promptly and properly when they are needed.

Controllers are not immune to this problem, either. When I first entered ATC, the radar I was blessed with having (since many areas radar wasn't as prominent as it is today) was an older-style ASR-5. Aircraft that were considered mine were represented with two parallel slashes, while those that were not mine were drawn on the screen as a single slash. There was no data tag telling me who it was, nor were there groundspeed or altitude readouts. These days, the tools have changed. We let the radar tell us who each aircraft is by tracking the targets for us, and we have other little gooides such as Range/Bearing Lines (RBLs, also known as "ribbles") and Predicted Track Lines (PTLs). In the old days, controllers had to make control decisions by determining which aircraft would conflict if left alone. Now, controllers can use these tools to see who will be a problem -- if they are used properly, that is.

Either way, it comes down to the same problem above for pilots: Mental atrophy. It's amazing how little a controller's job has changed, and yet just how much it has at the same time. The tasks that used to be part of air traffic control have gone from radar being a television, in the sense that you can watch it and talk about it, but you can't change anything viewed on it, to the point where we are now interacting with other controllers, and even with other ATC units, through it.

Reliance on computers is, in my opinion, not necessarily a good thing. The skills that we built foundations on in years gone by whither and die. What happens when "solid sewer effluent" hits the "fast-rotating air circulator", and we need to regain control? Are we letting computers run our lives to the point where we can't grab the stick, kick the rudder pedals and fly? And what happens as our skill levels further deteriorate over time?

This whole article was sparked by something last evening. Far from an incident of any significant nature, just a curiousity. A jet aircraft inbound to one of our airports in the Moncton FIR, cruising at FL330, began descent a little late. Actually, much too late. The crew was still at FL330 a mere 30NM from destination, despite ATC having issued descent clearance to them. They dove at over 7,000 feet per minute at one point in their descent, but still had to make a 360° turn to lose some altitude and slow down for the approach. How does this happen? Was the crew so engrossed in other things so close to destination, perhaps unrelated to the flight at hand, that they failed to notice where they were while the computer flew the plane?

And this sort of thing can creep into other areas of our jobs, too. One of the most common questions when a workplace turns to computers is, "What's it doing now?" followed by, "How do I make it do this?" or, "How do I stop it?" So we begin to lose our training in old-style methods of operation in favor of troubleshooting skills for the computer.

I'm not a technophobe, by any stretch. I'm just cautious about these things, just like any other change to a work environment. Anything that takes someone's attention away from the primary task (controllers controlling aircraft or pilots flying them) can't be all that good. Reliance on the technology has lead to a number of navigation errors over the years, whether it be because the computer wasn't programmed properly or because the instruction was misunderstood. It has also contributed some situations on the other side of the radio that could have become serious if not caught early enough. I just would like to see the basic skills taught, retained and even more-than-occasionally used to ensure we keep what we need to work with should we ever see the "blue screen of death" that would signify the end of our computer-assisted flight or radar picture (which actually is red these days for us).

Some readers remember my last post (oh so long ago) about Special VFR, and the fact that the post itself drifted somewhat from the post title. This post is more directly related to it, but it's more intended to spark some dialog about it than to discuss it directly.

Over the years, from both the tower and the ACC, I have been a witness to a number of requests for Special VFR. By definition, Special VFR is VFR flight below the normal VFR weather conditions, and applies only to controlled airspace, most specifically, control zones around airports. The term "controlled airspace" doesn't refer to an airport with a control tower. There are many control zones across the country established at airports that are themselves uncontrolled. The idea of a control zone in such a case is to provide controlled airspace to the ground to facilitate the control of IFR air traffic, and to increase the weather minima required for VFR flight to increase the margin of safety in a see-and-be-seen world.

This post is more of a question to start some dialog. How many pilots have been in a tough situation and have requested Special VFR to get into or out of a control zone (CZ)? Have you ever been denied a request for SVFR? Were you aware of the reason for a refusal, and what did you do?

SVFR is a touchy subject, from time to time. The majority of requests for SVFR go without further story, at least as far as ATC goes. But I know for a fact that there are hairy stories out there. I'd like to provoke pilots and controllers reading this into sharing some of their details of such stories, so that others (myself included) may leran from others. Be it something about rules and approvals, or pilot situations that aren't fully understood.

Got anything to share? Please post something in reply to this and we can start discussing. Either side, from ATC or from pilots.

A couple of fairly recent situations I saw brought this subject onto my radar. Both involve less-than-ideal weather, and both are slightly different while being largely the same. The biggest similarity is, given the title of this post, the weather. Marginal VFR doesn't quite cut it as a description, since both were pushing the legal limits of VFR.

In the first situation, the pilot was flying from Airport A to Airport C, passing by Airport B on the way. At A, the weather was marginal, as it was at C. As he approached Airport B, however, the pilot found himself flying at an indicated altitude of only 800 feet. Being quite familiar with the terrian in this area, I know that the pilot was within 500 feet of the surface. My bigger concern, however, was his reported flight visibility of between 1 and 3 miles. Legal VFR? For the airspace he was in, most certainly, even if only barely.

As he progressed east, I watched his track on radar. He was pointing at a range of hills where the terrain itself rose to between 550 and 600 ASL, but more importantly, there were several large antennas, one in particular topped out at 1050 ASL. When I informed the pilot of this, he opted to turn a little south to try and overfly the nearby city rather than the hills. Good, in a sense. But now he's operating over a city at 500-600 AGL with little guarantee that he can even keep that. I don't see how this conforms with regulations, but in terms of obstacles, it was a lot safer.

In the second situation, the pilot was going west initially in good VMC at 4,500. He then informed me he was descending to 2,500, then to 2,000, then to 1,500. I asked about his forward visibility, which he said looked good under the low cloud. I checked the weather reports at destination, and saw a history of weather specials (SPECI). They showed a continuously dropping ceiling and visibility over a fairly short period of time from 15SM to 3SM, with a remark in the sequence that the visibility from SW to N showing 1 1/2 SM (he was inbound from the east). So the system is moving in, clearly, and our pilot is still planning on getting in. Given that the airport is in a control zone, therefore requiring 3SM for VFR (though special VFR approval is available on request), should the pilot continue?

With all my IFR traffic around elsewhere I was busy, but still kept an eye out for this VFR pilot. He had confirmed earlier that he was neither IFR equipped nor trained, flying at altitudes of 1,000 feet or less (safe in this area, if you can see to avoid obstacles). The confidence in his voice was reassuring that he knew what he was doing, but as he changed his mind twice (once to return to point of origin, then a second time to press on to destination), the red flags that had already arisen began to wave fiercely. The dropping visibility to the west, the direction from which the precipitation was moving in, was the main concern. The pilot made it to destination in this case as well, minutes before a special weather observation was issued showing Instrument Meteorological Conditions (IMC).

My point? I'm not sure I have one. Afterall, what can I say? They both were provided information (one with weather, the other with important terrain/obstacle information), both made informed decisions based on what they were given (a good thing since in many accident/incident reports, information is received but duly ignored or discounted), and both succeeded in their flight. I guess I'm just concerned about VFR in IMC. I'm a fair weather flyer, myself, and have read enough incident reports and seen enough situations from the ATC side that over the years I've come to the point where I just don't like seeing pilots challenge the weather.

I'm just bringing this up in hopes that I can help others at least get to the point where they are seriously considering the information presented to them instead of missing the step when thinking about options. Pressing on isn't the only option in most cases. A local company recently posted a sign on their property with the slogan, "Never do anything you wouldn't want to explain to the paramedics." How about this one for us, "Never do anything you wouldn't want others to read about in the Aviation Safety Letter and wonder, 'What was he thinking?'"