Obviously speculation is dangerous, but it is clear to me that Asiana Flight 214 went way under the glide slope at the last minute and then landed way too early before the threshold of the runway at San Francisco International airport.
Runway 28L (and runway 28R) is a relatively long and straight approach (not a high angle approach). Weather was clearly not a problem.
What we DO know is that the plane landed too short of the runway. That’s all we know. Everything else is conjecture. But a preliminary look at the wreckage and debris field seems to indicate that the plane descended too fast and too nose-high. The wreckage is consistent with a massive tail strike (indicating the tail stuck first and with such intensity as to break completely off). My guess (and it is only a guess) is that the pilot attempted to then get the plane back in the air (not realizing he had lost the tail) and then of course lost control of the aircraft and the plane spun around.
The good news is that the CVR (the cockpit voice recorder) was not impacted by the crash or the resulting fire, so the National Transportation Safety Board (NTSB) will get very good (and quick) data on the last 30 minutes of all conversations in the cockpit (as well as radio calls to/from the ground). The flight data recorder, which records speed, temperature, angle of approach et al may be more difficult to recover, since it’s located in the tail. and we don’t know how much of the tail survived after it broke off.
It was a serious hard, nose up landing that is also considered survivable. On a day when weather was not a factor, it simply gets down to whether the airport’s ILS (instrument landing system) was working properly and/or whether or not the pilot of the Asiana plane was properly following his glide slope. In this case, the NTSB will be able to quickly RULE a lot of things out – engine, metallurgy, weather, structural. They will then be focusing instead on instrumentation, maintenance and human factors (translation: pilot error)
More as details and evidence develops.
By Peter Greenberg for PeterGreenberg.com