Why Don't Airports Routinely Film Takeoffs and Landings?

The crash of Asiana Flight 214 at San Francisco International airport on July 6, 2013, brings to mind a thought I've had since coming into the age of airplane-crash awareness.  I don't know when that was, but it was a long time ago.

There it is, there, in the title.

Plane crashes take place overwhelmingly on takeoffs and landings.  I just made that up, but I believe it strongly. Planes tend not to fall out of the air, although sometimes they do run into mountains or depressurize or collide or stray into fatally bad weather.  If something is going to go wrong on a flight, usually the craft either doesn't make it too far off the runway, or it come upon it the wrong way. Wait, here you go -- Airplane Crash Frequency by Stage of Flight -- only 8% of accidents take place while the plane is "cruising," that is, not taxiing, taking off, climbing, descending, or landing.  But, oh those cruising problems -- no fender-benders up there.

But thankfully few of them, so let's concentrate on a more useful datum, which is that most airplane crashes happen at and very nearby identifiable, limited areas known as airports. 

It would be relatively easy to capture clear images of each flight's taxi, takeoff, early climb, late descent, landing, and final taxi.  The concept would not be to capture a single aircraft on a single dedicated recording, but to install enough  fixed high-def cameras to cover all the runways, and some of the airspace nearby either end.  The day goes by without incident, no reason to hang on to the recording.  If there's a problem, the images are preserved and assembled from the various fixed cameras that recorded the plane's path.

It wouldn't matter how busy the airport is.  O'Hare in Chicago has about 2400 takeoffs and landings every day.   But since we're not trying to track every plane's path with a single dedicated camera but only asking each camera to keep a steady eye on one particular scene day in and day out, flights could come and go with any frequency with no greater burden on the system of recording.  Just turn them on and let them run.

I don't know how many cameras it would take to cover every open runway.  On some, you might even want more than one angle.   What if it took, oh, 200 cameras at a particular airport?  Some may be mounted on buildings or the low-slung signage along the runways.   Some may be peering out from the tarmac.   The plane comes into the frame, travels through the scene, and exits the other side -- at which time, another camera's field of view has already picked it up, and camera number one has already recorded the next aircraft to pass the scene where it's aimed.   Each camera records merrily away until it's determined that the recording was unneeded, and you start all over.

Issues:  Darkness; bad weather; expense of acquisition and maintenance; vibration from the engines and rolling on the runway.

Of course, this plan probably has some drawbacks or difficulties that I can't imagine.   But I'm thinking that  technology has reached the point that high-quality video may be acquired from small, efficient, optically sophisticated devices and that images can be manipulated and blended to show all those thousands of dramas when those gigantic vessels rise into the sky or float to the ground.  Amateurs film plane crashes on their cell phones, and those images are coveted for what they tell us about why an aircraft failed to thrive.  It would seem to me to be a simple, if perhaps costly, matter to institutionalize the practice.