Constant Plane Noise This Morning

[amy-s1.livejournal.com]

Let me say this first before you call me a whiner - watch the planes on this map for this morning of Friday 12/11: http://www4.passur.com/bos.html

You can replay any point in time with the menu bar at the top, you can even speed it up to 10X. Or you can watch "live" with a 10 minute delay.

Now, if those green planes dont go right over where you live, dont call the rest of us whiners. If they do go right over you, you know what I am talking about. My 5 month old daughter is constantly woken up by these planes and they can rattle the house.

Watch the flow of the planes coming off of runway 33L (the long one that points straight at Chelsea). The vast majority of them bank left and come straight over Davis Square almost every time. How about a little distribution over Harvard Sq, West Cambridge, etc?? Not to mention winds this morning are from the W/SW, not the Northwest.

Now, lets log complaints here: http://www.massport.com/logan/airpo_noise_compl.html

Comments

[somertricky.livejournal.com]

Couple of things:

a) I suspect it may be more important (comfortable, whatever) for planes to land into the wind than take off. Particularly with such a stiff breeze like today, I think you'd want to avoid a crosswind landing. Perhaps that is why the planes are landing to the west, and taking off over Somerville? I would think you'd try to avoid takeoffs and landings on the same runway.

b) Are pilots flying on visual cues? You could make an argument the planes are changing course and (roughly) following the Mystic River as it arcs towards the west. However IANAP, so WTFDIK?

[ukelele.livejournal.com]

I giggle at your unfamiliar, yet instantly clear, acronyms.

[diatomacearth.livejournal.com]

Wow, yeah.

[dcltdw]

I am also not a pilot, but here goes my understanding.

1. Planes both take off and land into the wind, because what you really care about is your airspeed, not ground speed. So a plane, sitting on the ground, facing into a 10MPH headwind has a 10MPH airspeed. This is hugely important, because it's your airspeed that dictates whether your wings are flying or not -- "not" meaning the plane has stalled and thus you're plummeting like a rock. So on takeoff, you reach your fly speed earlier; on landing, you have a lower groundspeed, which means you need less runway to brake. Pilots kinda like not having to use the entire runway for takeoff/landing in the same way that drivers (well, non-Boston ones ;) ) like not using all of the distance between their front bumper and the rear bumper to brake to a stop.

2. Planes change course as directed by the ground controllers. Given the fast pace of departure operations, I don't think spreading out the noise footprint is at all a priority. My understanding is that you want departing planes to clear the area as quickly as possible, since lower densities of planes mean a correspondingly lower chance of collision.

Whether a given plane overflies Davis or Harvard is due to the variability introduced by how long it takes the pilot to verify the course change, the plane's speed, and how much of a bank the plane goes into (I -think- that a plane with no passengers may bank harder if the pilot is so inclined, but holy woah that's just a guess).

[frotz.livejournal.com]

Some technical nattering by way of reply:

1. is kinda-sorta true, in that operating with any significant tailwind is pretty bad, but otherwise virtually none of the traffic is performance-limited on takeoff and the pilots get to just suck it up with a crosswind unless it's really howling. The reality is that they'll operate with whatever set of runways is vaguely compatible with the wind and will move the most airplanes per unit time.

2. Takeoffs basically get a departure heading (which way to turn once they're off the pavement) and then almost as soon as they're off the runway they switch from talking to the controller looking out the window of the tower to the controller looking at a radar screen up in NH. At that point they'll usually get a heading as close to the direction they're going as possible. The reality of that is that, given Boston's location, it's virtually always west or southwest, and indeed, depending exactly how fast they're coming off of the runway and switching frequencies that left turn will put them right here.

Believe it or not, they are really sensitive to noise issues, though it's a balance between that and efficiency. I've been in the radar room when a pilot with discretionary altitude assignment was dragging it in low-and-slow over a residential neighborhood and causing needless noise, and he got bitched out but good. (The supervisor on duty also commented that his phone would probably start ringing with noise complaints in a few minutes.) Also, some of these people are your neighbors (yes, air traffic controllers live in Somerville, please nobody tell Animal Control) and aren't oblivious to the bitching.

[thetathx1138.livejournal.com]

I suspect it may be more important (comfortable, whatever) for planes to land into the wind than take off.

The word you're looking for is "safe." :-)

Are pilots flying on visual cues?

Big jets? No, they're following a series of radar beacons. There are predetermined routes they're following, based on weather conditions, etc. If they're following visual cues something has gone BADLY wrong!

[808.livejournal.com]

While most Boston area jets fly into logan under IFR (instrument flight rules), it is quite common for jets to also fly VFR (visual flight rules). But there is a difference in IFR also. Even if Boston is under IFR guidelines, if the weather prevents using VFR as a backup, then certain conditions are put into effect to increase safety (like increase distance between planes).

So, yeah, pilots of big commercial jets use visual cues in most conditions - but usually as a secondary source of info.

At my house, my big complaint is that when it rains road traffic is too loud to sleep with open windows. But I accept it as part of living next to a big street. It stinks, but is offset by having a bus stop 50 feet from my front door (especially nice in the Winter!).

[thetathx1138.livejournal.com]

Well, I learned something today, I was pretty much told visual was only the primary way of navigating if everything else failed. Thanks!

[m00n.livejournal.com]

Seconded. Hence, as a non-driver, I look forward to the few days of the year when they close Broadway for foot races and parades. It's the only time out of the entire year when the sun is up AND I don't have to listen to road noise from my living room!

[somertricky.livejournal.com]

"Safe", thank you.

There was a period when flying to Upper Michigan from Detroit involved a substantial amount of flying to the northeast (even if you took off to the southwest, which is 95% of the time in Detroit) - until you could see the Pontiac Silverdome, then the pilot would bank and then fly northwest from that point. This would really piss off anyone alert enough to know where they were heading...

This would be comparable to taking off from Logan to the southwest over South Boston, doubling back to Cape Ann, and then flying northwest to Montreal.

We used to joke the pilot had to fly northeast until he got to I-75, so he could follow it north.