Periodic rant: Listening Watch - July '08 edition

[thatdaveguy]

My favourite is when they make their first call to you over, and over, and over...but they can't hear your replies. Why? Because their volume is down. That's fantastic!

[imarai]

Fantastic? No. Las Vegas is fantastic. This is frustrating. Idiotic forgetfulness is the cause. Many ab-initio pilots are taught to tune to 121.5 prior to shut-down, and 'listen'. Yeah, right. So they start up in the morning with the wrong freq. tuned in, the RF gain (volume) turned down, and the squelch on full, so no one except the over-flying Korean Airline flight enroute to Anchorage can hear them.
It isn't a big deal, because I've only experienced it a mere 134 times in my 30-year career, (I have two years to go..), so the average is much less than one-a-day!

Don't ask me about the number of times I've told pilots on night cross-country flights to turn on their navigation lights...

...or turn on their TRANSPONDERS to assist in TCAS alerts.

[C23flyer]

Many ab-initio pilots are taught to tune to 121.5 prior to shut-down, and 'listen'. Yeah, right. So they start up in the morning with the wrong freq. tuned in, with the gain (RF) (volume) (sound)turned down, and the squelch full right

That might explain the other day...coming into my home field with intention to land on the "active 14" only to find an aircraft doing touch and goes on 32. When I called him to clarify, no answer. When I get close enough I see he's doing his touch and goes on 14, but all his calls are for 32. His circuits and landings were nice though. I'm surprised he didn't call for a radio check as two other aircraft took off and he must not have heard them either.

Or even to turn on their TRANSPONDERSfor TCASalerts.

Maybe we can have a poll to see how many folks have forgotten to turn their transponder on - Never, Once, More than Once, Won't Admit.

[Old Dog Flying]

Recently, Langley and Pitt Meadows were classified as "Class C" cz and they both have the Mickey Mouse radar displays which is a land- line drop off of Vancouver radar...with the usual time delay. Naturally one is required to have a Mode C transponder to do circuits in these less than busy airports...BUT...for the most part, particulary at Langley, the target does not even show up on the display.

And yet this seems to be the sole means of seperation because traffic is rarely where the controllers say it is. Maybe they need to go back to basics and control using the Mark One Eyeball and look out the window.

And before anyone tries flaming me, I worked for 49 years in the system and FIRED NavCanada just a few years ago.

Dumb things happen on both sides of the glass and I'm not taking either side..just pointing out the problems that the pilots have with ATS.

[JigglyBus]

Out of curiousity, how are the 'radar displays' in Pitt or Langley different from every other tower across the country (except Whitehorse)?

[NJ]

Our tower radar feed in YZF goes from the site a mile or so from the Control Tower, down to Edmonton, then back up to our screen. There is a big delay because of that.

[Old Dog Flying]

The YPK and YNJ displays get their feed from YVR and mosaiced with the YYJ radar. Take into consideration the terrain, high rise buildings and the curvature of the earth..just kidding...the radar cannot see targets below 700' at either unit and in Langley's situation there is no radar contact below 1800' to the north and northeast.

Even with the slow speed light aircraft in the curcuit, there is usually a 1/2 mile or more displacement between the display and actual position.

Boundary Bay has the same problem but not to the same degree...usually the blind area is below 300'.

[NJ]

Well learn something new every day.

[grimey]

Uh, time delay? What are you talking about? NARDS displays from either RDPS or direct inputs. There is no time lag other than that which is introduced by the rotation of the antenna. Doesn't matter where on the planet you drop the feed. You've heard of the speed of light, right?

The time delay on NARDS is small enough that it can be safely ignored. Working in YTH, 750km north of our RDPS, (and so 1500km round trip for the signal) the targets on radar still corresponded within a couple hundred feet (at worst) of the aircraft. If you're worried about a few hundred feet to maintain separation, or to discriminate traffic, you're doing it wrong.

[JigglyBus]

That was my point, but I just wanted to see Old Dog dig himself a deeper hole.

I didn't want to 'flame' anyone, but I don't know how you could be a controller for '49 years', as he says, and be so mistaken on
such a basic concept.

Perhaps this has something to do with why he 'fired Navcanada' a few years ago.....???

[Old Dog Flying]

The reason that I fired the company was just because of responses like this. I had enough of the BS. I was referring to the sweep delay vs. the "out-the-window"
actual position of traffic. I frequently have traffic pointed out that is up to a half mile from the position given by the controller and this is in the circuit that is being controlled using NARDS and not the MkI eyeball.

I've worked with a few newbies who would work their hour in the runway position and never look out the window to the point where the day I walked out, I witnessed one individual have 3 occurrances which were ignored...thankfully most of the tower guys and gals are not in that category.

The only digging that I do is shovelling the droppings when it gets too deep

[scrambled_legs]

I don't understand why there's even any discussion about the potential difference between the real-time position of an aircraft and the RADAR displayed position of an aircraft? Maybe it's relevant if you're looking out the window and trying to correlate geographic references to RADAR displays for a given aircraft, but for the purposes of IFR separation that delay (of at most 5 seconds between the RADAR display and the real-time position) is totally irrelevant. And even for VFR purposes, a 5 second difference in position should not be relevant...

Do the math on 186,000miles/second vs. 1500kms. Relevant at about the 50th decimal place on a value that is already in the millionths of a second to begin with.

Do the math a 5 second delay of 2 cessna's doing 120kt's head to head is a difference of almost 1/2 mile. Take 2 Hawks head to head at 300kts and 5 seconds is almost a full mile difference between their position on the radar and out the window. That's pretty relevant in my mind when VFR aircraft are often separated by as little as a 1/4 mile even.

Old dog's right, when it comes to VFR separation most units radar isn't real time enough to be reliable, you have to keep your eyes out the window. When traffic was 11 o'clock it is now 12 when it's 1 mile ahead it's now 1/2 mile when looking at the traffic turning crosswind to downwind on the radar, out the window, they're often mid downwind. I'm not sure what causes it but some days are worse then others and at their worst, they're completely unreliable when separating two planes one out the window and another on the radar. Whether you're on a direct or mosaic field it also seems to make a difference. As far as not seeing targets below the downwind, that seems to be common place in many units.

The radar is still a significant advantage and after using it for a while, you start to compensate for the lag and assume that the aircraft are significantly ahead of their target depending on how things look out the window that day. I'm not sure what the argument is but if it's whether you can use solely the radar and a runway scan to control, the answer is no.

[JigglyBus]

The 'discussion' is regarding the condemnation of YPK and YNJ for apparently relying solely on their 'mickey mouse radar displays' for passing traffic, which apparently as old dog says has "usually a 1/2 mile or more displacement between the display and actual position."

It's my opinion that these statements are completely false.


Scrambled eggs, regarding your math.....

If two 120kt A/C were head to head, 5 seconds is 1/3 mile.

Firstly, perhaps nitpicking but, cessna's in the circuit rarely do 120, more like 90-100.

Secondly, if they are in the circuit and head to head, closing at 120kts each, you have bigger problems than passing traffic.

Thirdly, I'm not promoting the use of radar in the circuit. Obviously looking out the window is going to be more accurate.

Lastly, if 1/3 miles is SOOOOO bad, I'd like to see an expert look out the window at a distance away of 3-4 miles, and estimate the distance between 2 aircraft routinely with an error factor of less than 1/3 mile. It's doable, but not from a rookie.

But in reality, we're talking extremes here. If two a/c are going 90kts and the tracks are perpendicular to one another, the error is going to be much less. 5 seconds is more like 1/8th of a mile. Eyeball error at 3-4 miles has to be more than that.

At least mine is. But I'm not superhuman like some others.

[scrambled_legs]

Jiggly, you completely missed the point...

We have P210's here that can do 150kts in the downwind so 120kts isn't unrealistic and I wasn't referring to the circuit traffic. You're right, 5 second delay is .333 of a mile to be exact.

When you're passing radar traffic (where both planes are out of reasonable sight and both are on radar) you have to account for the lag. Where traffic shows to be at his 11 o'clock passing from left to right, tell him its at his 12 cause it'll be there in reality. Or if they're head to head estimate slightly closer than they appear... etc.

If you're using radar to separate the circuit traffic or low level traffic not on radar with inbounds/outbounds that are, don't rely on the radar target to be where it is but rather plan on it being a ways ahead of radar position in reality. You have to find the targets out the window to know the true separation then.

I'm not superhuman either but trainees love to oggle the radar and treat it as gospel. What Old Dog is saying is true to a point. There are relatively large variances between radar and actual positions. You can't trust it. period.

[C23flyer]

What is the range of your radar scan? In most cases you'll still be picking out targets that I haven't seen yet as a pilot. If you pick it up on radar, you can bet that the eyes in the plane will be scanning for the target and have it located shortly thereafter. Correct?

[JigglyBus]

Scrambled,

Again, I'll have to disagree with that last statement. I trust the radar somewhat. I trust it to lag about 3-5 seconds.
It is very easy to predict an aircrafts position 3-5 seconds from now, and that's what we use to predict traffic positions.

Heck, it takes me more than three seconds to actually say the words "GABC traffic 2 o'clock, three miles, eastbound, a cherokee at 1500 feet". So I have to account for that amount of error as well. And we do, and it is easy.

In the end scrambled you are saying that you agree with this statement "Even with the slow speed light aircraft in the curcuit, there is usually a 1/2 mile or more displacement between the display and actual position."

I do not. But everyone is entitled to their opinion.

[scrambled_legs]

When my radar shows an aircraft turning crosswind to downwind, out the window he's often 1/3 of the way downwind, if he even shows up at all. We also often have targets ghost out on final then reappear 1 mile left abeam the threshold on one of our runways. We also often have targets swap tags momentarily. We also often have targets briefly show up where there are no planes. Take it for what you will but when you're moving up to 1,000 movements a day... that's a pretty freaking big variance, numerous faults, and something you can't trust at all. I can only use it as an aid to looking out the window and that's all. If you're only moving up to 400 a day, then who really cares, just give some extra room... you've got lots of holes to spare no matter where the planes are in reality.

[Old Dog Flying]

Try stretching the circuit out using the radar with aircraft turning 2 mile final getting very low...the target disappears and if it isn't on radar it isn't there ...right?...Wrong! Then looking at the display..nothing there and taxi an aircraft to position to wait...and the guy on short final that wasn't there has to pull up and go around. All too often I watched this happen and when I mentioned looking out the window, I got "I know as much about this job as you do" and the person was licenced at our unit just the week before.

Or "no more than 4 in the circuit..you're making us look bad"...after the guys decided that "traffic management" was the key to cutting down the work load.

Try telling a pilot that he can't have circuits because the circuit is FULL with 2/3/4 aircraft in the circuit. And management was clueless about what was going on or he didn't care.

I worked with a lot of really great people over the years but it only took a few to make me pull the plug.

[JigglyBus]

You guys are arguing whether or not radar is 100% foolproof, to be used and trusted under every circumstance.

I'm not sure who's arguing against you.... it ain't me. But carry on if you wish.

I reiterate my point from the beginning. I disagree with the statement originally made.

Old Dog, I'm not sure when you left ATC, but there are procedures in place to safeguard against the shenanigans you are refering to. It's called an OI. If people are being taxied to position with 'forgotten' a/c on short final, that is an OI. It should be report BY YOU, and it will be investigated and dealt with. It's not simply dealt with by a few childish words between you and the other controller. If in fact as you say "All too often (you) watched this happen" and did nothing about it, then you are as much at fault as the controller in question.

Is this the case?

[scrambled_legs]

Huh??? Pilots can tell what their heading and track is and they should be looking for traffic relative to their track as taught in any private pilot course. They cannot tell what sort of lag you get in the radar and compensate for it, that's our job. What that reference has to do with this is beyond me.

We're not enroute controllers, with 5 miles being a near hit. In our world, slight variances in position make a big difference as we routinely have 8 aircraft within 5 miles of each other. If we just go off the radar and tell him to follow the guy at his 11, he could easily follow the wrong guy. Like several people have pointed out, the Towers have a significantly larger delay on their radar due to the slow land lines feeding the info from the center to the tower. You can even notice a difference in the delay by switching from direct feed to Mosaic.

Jiggly, I'm not arguing that the radar isn't foolproof, I'm saying that whenever you can verify the accuracy of the radar out the window, do so. As old dog said, many of the new trainees bury their head in the radar and trust it fully and you appeared to take issue with that. So if you agree with him, then what sort of hole is he digging? The only thing I don't agree with that Old Dog said is that Langley is busy.

[Old Dog Flying]

Scrambled-legs: Langley is unfortunately located between Boundary Bay and the crowded practice area at Glenn Valley and when you throw in a constant stream of 88s along with the circuit traffic then add the ESL problem, it is busy.

I did not "condemn" the folks in Langley or Pitt Meadows...it was an observation that a few trust the radar to the point of being dangerous. As for not snitching on the people that I worked with...well that is done all too often by people trying to make browny points with management and it is a game that I refused to get involved in.

[scrambled_legs]

Come on old dog, if you start telling me about how difficult Langley is to control, you'll lose all your credibility.

[scrambled_legs]

The AIM only states that we will not correct for wind and to look for traffic in the O'clock according to your track. It says nothing about radar lag because it is a phenomenon that is not acknowledged to exist publicly. THAT REFERENCE HAS NOTHING TO DO WITH RADAR LAG. VFR controllers know what I am talking about and you do not, but that is fine as it doesn't apply to you as you're IFR with planes staying miles apart. It's one of the first things that you'll be told in VFR training. How many times have I heard keep your eyes out the window that plane is already on base, not downwind etc.

I will not read the radar without applying a correction in my mind, as It's a hell of a lot safer having planes follow their actual traffic and not what the radar shows or constantly come back and say we have no traffic at our 11 but we have traffic at our 12. I'd rather avoid that, the real safety issue, then worry about applying some obscure reference from the AIM that has nothing to do with radar lag, only wind correction and watch planes come together.

CPL I say this with the knowledge that I know nothing about being able to control IFR, you have no idea how to control VFR or what problems we face with the radar. You have no idea what sort of lag is present at a VFR tower vs. a center and neither do I, but I do know that our lag is significant as I can see it out the window, and that it varies from unit to unit and hour to hour. The only way to determine the actual lag would be to have the screens side by side. Whether its the Exceeds, Oids, Nards, Ncams, Internet etc. all feeding through a land line or the processing at the center, something is causing a significant delay.