On Monday, we ran a chart that compared the crashed Asiana 214 flight's last minute actions to four other flights that flew the route and nailed the landing.
Walter Hickey / BI
This by and large confirmed for us the information coming out that claimed the reason the flight crashed was that it wasn't going fast enough at landing compared to what it should have been doing.
Luckily Phil Roth — a research scientist at User Systems Inc. — saw our article and published an outstanding review of what doomed July 6th's
He pulled a lot more flight data than we did, and the result is fantastic.
From Roth's blog post:
Specifically, I wanted to see if the ground speed profiles of flights using the Instrument Landing System differed from those that didn’t have that luxury. The ILS was out of service on runway 28L at SFO on July 6th. I found reports that it had been unavailable starting somewhere between June 1st and June 15th. To be safe, I compared Asiana Flight 214 landings that occurred before June 1st (with the ILS) to those that occurred after June 25th (without the ILS).
His highly tentative results are cool. Roth found the Asiana Flight 214s that landed without assistance from the ILS — just like the July 6 crash — seemed more consistent and safer than those that used it.
The resulting chart is awesome, and shows just how slow the crashed Asiana Flight 214 was going compared to what it should have been at:
As you can see, the crashed Asiana 214 was going profoundly slow at landing, which has been linked to why it didn't nail the landing.