Control Towers Don't Do What You Think They Do

[Music] well the cub really is broken i've been trying to free up a stuck valve with some gentle taps from this wooden hammer handle didn't work looks like i have a rope trick in my future i was going to segue that into a video scene where you imagine you're walking into a hangar to have a learned conversation with some expert but the whole thing is just a fantasy setup and here's what it looks like but at least you can see how many talented people it takes to create this multimedia magic and anyway youtube videos aren't conversations there's some guy flapping his lips for 10 minutes the real video starts now you know i've never understood the fetish some pilots have for flying into airports with control towers personally i'm anti-social i don't like talking to people that much okay at all and only once in my flying career did i need federal assistance to find a runway and even then i would have found it on my own eventually certainly later that same night also it's more fun to hurl schoolyard insults on a unicom frequency than it is to roger up a landing clearance like you really got to have permission to land well anyway i guess i ought to talk to people more because when i wrote this bold statement in my abweb blog a couple of weeks ago several readers pipe up to say hey i didn't know that now i could offer some smarm about gaps in pilot education and the baby jesus knows i'm good at smarm but since i've been writing about this for the last 25 years i kind of figured everyone has risen to my level of useless trivial knowledge but well maybe it's not that useless after all so to the pop quiz question what does a control tower do how would you answer go ahead i'll wait the answer is it keeps airplanes from tangling on the runway and also sequences them in the air so they won't tangle on the runway and that's pretty much it other than yelling at you if you taxi the wrong way or cross a runway you're not supposed to all of which right keeps you from tangling on the runway also towers used to exist for saturday morning cub scout tours but kova didn't kill all the controllers the tours are surely toast on now but let's just go over this stuff anyway for no other reason than to keep me from writing stupid in my blog first a definition the job of air traffic control is to provide a safe orderly and expeditious flow of air traffic controllers get that tattooed on their palms at atc school the safely part is done by separating airplanes in the air and on the ground in the air there are standards for this for airplanes on ifr flight plans is three miles laterally or one thousand feet vertically if the three miles can't be maintained it's five miles if the airplane is more than 40 miles from the radar site but this is important that separation is done by tracons and centers it is not done by towers and this separation applies between ifr airplanes vfr airplanes don't get no separation unless they're flying in big city class b or class c air space that's a subject for another day but even towers at those big airports live to separate airplanes on the runways that's all they do atc takes this separation stuff kind of seriously and used to be pretty draconian about it if a controller's actions result in the loss of separation known as a deal in the atc trade it's not a good thing uh uh official separation hey um like three miles not 2.8 okay okay used to be the controller got rudely yanked off position interrogated and maybe even decertified and retrained but these days not so much the faa is more reasonable about it even though a deal is still not a good thing you'll hear the term vfr tower or sometimes visual tower but this is one of those shorthand things that doesn't officially exist in the aeronautical information manual like when tom cruise asked about the mess hall and a few good men corporal would you turn the page in this book that says where the mess hall is please well lieutenant kathy that's not in the book sir you mean to say in all your time at gitmo you've never had a meal no sir three squares a day sir i don't understand how did you know where the mess hall was if it's not in this book well i guess i just followed the crowd at chow time sir more questions you know i'd do the same thing we might be doing some version of that with vfr control towers everyone should know what vfr tower means even though i am now informed that a lot of us don't know it means a tower in class d airspace without any official radar capability nor duties to separate airplanes in the air of the 500 plus control towers in the u.s the majority are vfr towers in class d airspace although these may underlie class b or class c airspace like this mess in california some of these towers have one of these things it's called a debrite and it feeds radar data from a nearby tracon radar site to the controllers in the cab some towers have a newer displays from the faa stars replacement program either way these displays give controllers a good picture of where the traffic is like a set of powerful binoculars but except in a few limited circumstances it can't be used to vector airplanes or provide separation because towers don't provide this service and in those rare cases where vectors or headings might be suggested to vfr traffic the aeronautical information manual is pretty clear so you can blow it off if you want to but that doesn't apply to directives you get from a center or a tracon if you've signed up for vfr flight following you have to follow those or you can damn well cancel the advisories back to the question what does a control tower do it does this this is a diagram in the controller's manual known in the trade as the .65 and it specifies how much runway separation the tower has to provide between airplanes of various sizes which the faa calls categories these apply to both landing and takeoff at any airport with a control tower there are also takeoff separation requirements for wake turbulence you don't need to know these numbers knowing the concept is enough class d vfr towers can and will sequence traffic as in follow the baron on left base runway 2-7 they set the take-off sequence and even tax the airplanes to the runway in an order that promotes efficiency and runway separation and they'll also set up spacing in the service of making sure the runway separation works out spacing is not separation it's just planning a controller can order for example an extended downwind a short approach i'll have to write 360 for spacing call your base turned and so on and this is why towers don't provide airborne separation because their eyes have to be on the runway and the pattern not the distraction of a debrite display a control tower will when it's able alert pilots to other traffic in the area but it's not required you might not get the point out and point out by the way is technically a term that applies to radar not visual traffic i'm using it kind of liberally here and just to reinforce this mid-air collisions have happened in airspace controlled by class d towers with both airplanes talking to the tower the most recent one was the centennial airport collision in colorado between a cirrus and a metro liner in 2014 another series collided with a helicopter in the pattern at frederick maryland's class d airport the ntsb cited the failure of both pilots to look for traffic that had been pointed out to the cirrus pilot at least and also faulted the controller for failing to prioritize monitoring traffic over listening to a clearance read back two other mid-airs occurred in the chicago area one between a cessna and a zlin and another of bonanza and a cessna 172 near the then mig's field the zlin crash killed well-known chicago radio personality bob collins his passenger and a student pilot in the cessna they hit the subsequent crash into a hospital caused a major fire and a 32 million dollar insurance claim two people on the ground were injured in that accident the pilot was faulted for failing to see the cessna he hit and the controller for inadequate sequencing the same cause was cited in the 1997 migs crash which killed seven people both airplanes were talking to the tower and had been pointed out to each other the pilot of one the cessna had been asked to report a beam the field but failed to do so two airplanes collided near the airport there are quite a few other accidents like these at class d towered airports citing them here just reinforces the point that a vfr tower doesn't provide separation and may not always offer accurate or timely traffic alerts both the aim and the 0.65 make it crystal clear that it's on the pilot to see and avoid other traffic it's not the tower's job and that's true whether there's a radar there or not some people think that a half dozen midair collisions a year show that seeing a void doesn't work if that were true half of us would be dead it just doesn't work all the time it's not perfect now that more airplanes are equipped with adsb the deck is stacked more in your favor but not everyone has the adsb in that will display traffic and remember you don't need adsb to fly in class b airspace you don't need a transponder either for the past 22 years mid-air collisions have been trending downward but the totals have been spiky for no explainable reasons 2000 for example was a horrible year followed by a below average year in 2000 four of those accidents occurred at towered airports including the bob collins crash class d airspace or not midairs don't represent a huge risk but it's not trivial either traffic alerting gear of various kinds may have improved things but you'd have a hard time proving it because the numbers are so small this technology began to be fielded seriously around 2006 or so but we don't know how many airplanes had it by year it wasn't a lot during those years adsb came into wider use beginning in 2018 and since 2020 adsb out has been required in most airspace but not all airspace and not everyone installs the adsb in that provides traffic alerting while adsb is a huge plus in avoiding the midair you still have to see the airplanes you hope not to hit so in the vicinity of an airport your eyes still need to be outside the cockpit so to me the point is this flying into an airport with a class d control tower isn't that different from one with no tower at all yeah you'll get some sequencing help and point outs and someone to fetch an ifr clearance but in both cases it's on you to see and avoid the other airplanes just like it always has been look we all have lapses in doing this it happens to everyone including me and ever more often because of all the distracting crap we put into modern panels and then just to make it worse at a couple of ipads controllers and towers do make mistakes too but their chairs don't go crashing to the floor in flames as a result pilots obviously have more skin in the game which is why i'm kind of blase about control towers but if you're not just keep in mind who's supposed to do what the pilot part is not hitting other airplanes the tower will concentrate on making the runway safe and maybe sometime soon they'll let the cub scouts back in for avweb you know the rest you

Channel: AVweb

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Id: FM3dmaC4z8E

Length: 13min 55sec (835 seconds)

Published: Sun Jun 06 2021