The FDR / CVR will record much data, including controls and communications. They won't record:
Other aircraft or objects in the vicinity.
Parts of the aircraft which have separated. Look to the telemetry data / communications in the case of the Columbia shuttle disaster as ground control tried to work out what was happening with the off-range readings for tire pressure sensors -- as the wing of the shuttle was being carved out from the inside by 6000°F reentry plasma.
Fine-grained movement of the aircraft, its components, the interior, fire and/or smoke, debris, etc, at 16-1000 frames per second 1080p resolution.
Runway incursions, airspace incursions, and other near-miss phenomena.
Small aircraft without FDR/CVR equipment.
The equipment cost is minimal. Equipping the plane itself with video capabilities would be an additional feature, but simply having ground, runway, approach, and departure path video would be useful. As others have noted, not only for the (very rare) emergencies, but for the far more common "incidents".
On the negative side: inclement weather, including rain, snow, and fog (the latter being common at SFO) would limit utility somewhat.
Other aircraft or objects in the vicinity.
Parts of the aircraft which have separated. Look to the telemetry data / communications in the case of the Columbia shuttle disaster as ground control tried to work out what was happening with the off-range readings for tire pressure sensors -- as the wing of the shuttle was being carved out from the inside by 6000°F reentry plasma.
Fine-grained movement of the aircraft, its components, the interior, fire and/or smoke, debris, etc, at 16-1000 frames per second 1080p resolution.
Runway incursions, airspace incursions, and other near-miss phenomena.
Small aircraft without FDR/CVR equipment.
The equipment cost is minimal. Equipping the plane itself with video capabilities would be an additional feature, but simply having ground, runway, approach, and departure path video would be useful. As others have noted, not only for the (very rare) emergencies, but for the far more common "incidents".
On the negative side: inclement weather, including rain, snow, and fog (the latter being common at SFO) would limit utility somewhat.
http://www.faa.gov/airports/runway_safety/news/runway_incurs... https://en.wikipedia.org/wiki/Runway_safety http://www.thestar.com/news/canada/2013/05/06/runway_incursi...
From that last (and presumably applying to Canada, not the US):
A Star analysis of Transport Canada data counted 5,677 incursions by aircraft, vehicles and pedestrians since 1999, averaging almost 400 a year.