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There's an mp3 of the radio chatter here: https://forums.liveatc.net/atcaviation-audio-clips/7-july-ksfo-ac759-go-around/ https://forums.liveatc.net/atcaviatio
by charlietran 9y ago
There's an mp3 of the radio chatter here:
https://forums.liveatc.net/atcaviation-audio-clips/7-july-ksfo-ac759-go-around/ https://forums.liveatc.net/atcaviation-audio-clips/7-july-ks...
> Audio from the air traffic controller communication archived by a user on LiveATC.net and reviewed by this newspaper organization showed how a the confused Air Canada pilot asks if he’s clear to land on 28R because he sees lights on the runway.
> “There’s no one on 28R but you,” the air controller responds.
> An unidentified voice, presumably another pilot, then chimes in: “Where’s this guy going. He’s on the taxiway.”
> The air controller quickly tells the Air Canada pilot to “go around.” telling the pilot “it looks like you were lined up for Charlie (Taxiway C) there.”
> A United Airlines pilot radios in: “United One, Air Canada flew directly over us.”
> “Yeah, I saw that guys,” the control tower responds.
- desdiv 9y ago.
- grandalf 9y agohttp://ieeexplore.ieee.org/document/369434 http://ieeexplore.ieee.org/document/369434 On the other hand, AM is simple and cheap and usable worldwide without significant investment.
- pdelbarba 9y agoExcept when said AM transceiver is inside an airplane, then it's thousands of dollars :P
- sigstoat 9y agothey still use AM because higher powered transmitters (which will generally be the tower) can overpower weaker transmitters (planes). i'm given to understand aviation is enamored of that feature. > Just imagine the economic damage that a single asshole can do with a high-powered transmitter near an airport. the pilots could probably just pull their cell phones out and call the tower. there is much worse trouble single assholes could get up to.
- PhasmaFelis 9y agoI'd imagine, as well, that a transmitter powerful enough to drown out a control tower would be very, very difficult to conceal.
- RX14 9y agoI think you'd be very surprised what a lot of power and a shit antenna can do. Obviously won't last when someone comes along with DF equipment, but it really wouldn't be hard to conceal visually.
- floatingatoll 9y agoVisually is the key word here. RF-wise, you may as well put a beacon on the moon and scream "LOOK AT ME" for all the good it'll do when the very, very angry FAA/FCC vans show up.
- deleted 9y ago[deleted]
- dmitrygr 9y agoIt is a very Silicon Valley thing to assume that everyone else is an idiot and needs to be disrupted, with not a thought given as to why things are the way they are. Sort of funny to watch it from the side I assure you that there is a reason AM is used. The reason is that in the case that two stations are transmitting, everyone will be aware of it and the stronger signal may be heard. This is not something that FM can guarantee. And a digital protocol requires a much better signal (where old analog tv gave snowy picture digital TV gives nothing). Not to mention the insane costs that digital radio retofitting would require of every single plane in the sky. Edit: parent seems to have deleted his post. It previously asked condescendingly why we still use AM for comms in the air.
- wfunction 9y agoOkay, but do military-grade systems use AM like this too? I imagine their needs aren't any less than those of civilians, and I imagine they've gotten their communication systems to work just fine. So what's the issue?
- tuxxy 9y agoAirlines don't need military systems which are used more for confidentiality and OPSEC than other things. In the field, militaries tend to avoid radio communications for various tactical reasons. Submarines are a great example of this.
- ptaipale 9y agoMilitary-grade systems may not be any "less" but their needs and priorities may be different (e.g. secrecy). So different technology may be used, without any contradiction to why the current one is good for civilian air traffic.
- Aloha 9y agoGenerally, yes. There are some digital systems used for aircraft to aircraft communications and for a tactical datalink, but yes its AM for landing.
- 9y ago
- Aloha 9y agoThere is a very good technical reason we still use AM. AM is not prone to capture effect, wherein the loudest signal captures the receiver. With AM, you can hear multiple people talking on top of each other at the same time. https://en.wikipedia.org/wiki/Capture_effect https://en.wikipedia.org/wiki/Capture_effect For uncontrolled radio situations where you have a number of unknown people who need to access a radio channel, neither digital nor encryption bring any wanted benefits. As a note - the audio from this recording is very clear to me - I've heard far worse out of scratchy narrowband FM.. with AM the weaker the signal generally the quieter it is - but not generally that much noisier.
- lb1lf 9y ago-Agreed, intelligibility is pretty good. I've been into amateur radio for ages, presumably that has trained my ear. I routinely copy voice signals which are just a garbled gibberish to innocent bystanders. (Same obviously goes for ATCs and pilots to an even larger degree, being exposed to comms several hours a day)
- Aloha 9y agoHey There OM :-) Yeah, Even with P25 - the same skills apply, but instead of pulling it out of noise, you're relying on your skills of interpolation to suck it out of the noise. Still it's a neat parlor trick :-D 73's
- InclinedPlane 9y agoYup. FM is great for noise rejection. But any signal which is not "the one true signal" counts as noise. So FM interferes with other FM signals mightily and the most powerful one tends to "win". Whereas with AM the signals just add on top of each other.
- tialaramex 9y agoMmm. Here's the thing, I think we heard a lot of the same arguments before DSC took off for marine radio. They too have uncontrolled radio, a large number of unknown people who need to communicate with whoever happens to be nearby, they have more powerful transmitters owned by governments that "need" to shout down less powerful ones on transport vessels occasionally. Now, maritime radio IS a different environment. I'm not suggesting that DSC should just be dropped in as a replacement for AM analogue transceivers on planes, but I _am_ saying that I don't buy the theory that it so happens AM analogue is the right choice and not just the result of inertia.
- PeCaN 9y agoI will never understand this mentality of Silicon Valleetards to take something that already works rather well and make it 100× more complicated for questionable benefit.
- narrator 9y agoThe "Where's this guy going" unidentified person on the channel prevented the worst accident in aviation history. Great Job! Give that guy a medal and a movie.
- jackweirdy 9y agoThis is like Sully all over again, but with only seconds to extract story from instead of minutes!
- dx034 9y agoIt's likely that the controller would've seen it as well after the Air Canada pilot indicated that he saw planes on what he believed was the runway. Even if not, the pilot would've probably aborted the landing since he saw the other aircrafts. So it was certainly a dangerous situation but I doubt that a crash would've happened without that pilot's comment (it was certainly helpful though).
- PhasmaFelis 9y agoYeah. When reading about modern air disasters, you often hear that five different things had to go wrong at once for them to happen. In this case, one or two things went wrong, the rest of them went right, and everything was fine.
- 9y ago
- dav 9y agoThose fixed wings people are unflappable.
- throwanem 9y agoYou monster.