Aviation In Canada

Sunday, May 08, 2005

Free Flight, Again

In yesterday's post, I may have presented the view that I'm against Free Flight. I am in some ways, but in many senses, I believe that parts of it are good.

Personally, I don't trust TCAS enough, and there are several reasons for this. First off, not everyone will have TCAS, and TCAS will only work well if both involved aircraft (assuming only two) have it. This doesn't account for the Cessna 172's and the PA-31's and other such aircraft that will still frequent many airports that will fall outside the purview of any remaining terminal control units under the theory of Free Flight. There will still be aircraft meeting up with airliners in non-TCAS contexts. I've also seen TCAS give problematic and erroneous directions to the piltos (happily, the pilots disregarded the instructions, knowing full well that they were going against regulations, but also being well informed of the nature of the traffic and the situation). Mind you, this part of my arguement has become much more rare since TCAS first appeared on scene, but it occasionally happens.

Now, the direct routings part, I agree with. We have better displays in the ACCs now than we had 20 or even 10 years ago, and the concept of not knowing where an aircraft is going if the point is beyond the range of the scope has gone by the wayside. We can draw lines on our screens to any point and see exactly what the track would look like. And with the exception of converging routes or opposite direction traffic, these sorts of direct routes often provide enough lateral separation to allow for unrestricted climbs and descents.

The are some issues though. First off, as I mentioned yesterday, a direct route from point A to B isn't always good, considering airspaces involved. Restricted areas and military flying areas exist, some permanent, others activated by NOTAMs. It's clear to me that many pilots are not aware of the restricted airspaces that lie near their flight plan routes, and therefore are prone to asking for routings that go through some of these areas. An ATC two FIRs removed is not likely to be aware of such a block of airspace, and will grant a clearance if it works for him. He is expecting that the pilot will know if it's good or not, and he's only concerned with his traffic picture, which doesn't extend much beyond his area of responsibility.

Secondly, and this is just as important from our perspective as ATC, is that we have been bombarded with information and requests to stop clearing aircraft on direct routings. In the recent past, we've been giving aircraft direct POINTD on a flight plan that has points A, B, C, D, E, F and G in it. This winter, NAVCANADA, the company that runs the Air Navigation System in Canada, produced a video for ATC staff for our recurrent training that had guest speakers -- including an Air Canada captain and a Westjet dispatcher -- that told us not to meddle with their flight plans. They informed us that we weren't helping when we issued these routes, since the dispatchers have to deal with gate times and weather systems that "controllers are not aware of" and therefore saving those extra couple of minutes in the air often means sitting on the tarmac waiting for a gate to open. So the delays are, once again, ATC's fault. As if that wasn't enough, we have a memo on the books now that was spawned by a letter to our unit chief from IATA, the International Air Transport Association, telling us to cease and desist issuing direct routings, for the very same reasons. It seems from our perspective that the airlines are serious about telling us to stop trying to help them.

I understand the nature of long routes of flight and how weather systems can affect flight times. But when a pilot asks for direct A and we clearing him there, we surely can't be blamed for that. Besides, when we issue an initial vector to the flight plan route and the pilot returns with a readback and a request for what we've been giving him all along, it just wastes airtime for both ATC and the pilot. And a pilot can always refuse the direct routings offered, if these things are, in fact, serious as these messages we're receiving seem to be. So I guess I'll just sit back, wait for pilot requests and see what develops.