document.write(" serif">News and Public Relations
Deborah Hersman, The NTSB's Chairwoman, has taken some flak in the last few days. But from my perspective, she is one of the few in responsible positions who are looking good.
First a minor annoyance: on Saturday and Sunday news outlets kept repeating a young witness's observation that Asiana 214 came in “low and fast.” Many immediately available facts, including where the aircraft came to rest, made it a slam dunk that the aircraft was, instead, flying way too slowly.
Then on Monday the Korean Government announced they would be “inspecting all Korean B-777's”. On Tuesday and Wednesday various pilot unions called for Ms. Hersman's head, saying presumptions of pilot error were speculative and premature.
Please. I am used to the power players grandstanding their interests, but this is amateur hour. There is only so much ignorance out there.
The Last Thirty Seconds
Now let's get back to what we know. The cockpit cleared the breakwater nicely. The main landing gear and the tail did not. The speed at impact was 106 knots, within a knot or two of the stall speed. (The approach speed should have been 137 kt.) One and a half seconds before impact, engine power increased. Passengers in seats just behind the wing could see spumes of water being thrown up. At four seconds before impact the stick shaker operated, signifying an impending stall. At seven seconds someone is heard on the voice recorder calling for an increase in speed. In his interview the training captain said he went to push the throttles forward but the trainee already had. (Notice at least 5 1/2 seconds elapse between advancing the throttles and the increase in power. Seven seconds spool-up from idle is typical for a fanjet engine.) At 500 feet altitude the training captain became aware that they were too low (the PAPI lights were red over red) and he asks the trainee to pull back. The training captain also notices they are not aligned with the runway. Ms. Hersman says at that point they knew they were low and they were making lateral corrections to line up on the centerline of the runway.
These are the bare facts.
Flight Preparation in Seoul
Now let's go back twelve hours or so to the pilots' briefing. The dispatcher has already produced the flight plan with its route as close as possible to the minimum time track. The weather is good over the Pacific and at destination. Most likely they have fuel for a close alternate, such as Sacramento. It looks easy. But somewhere in the data available to the dispatcher and pilots are these two lines:
ISFO 06/005 SFO NAV ILS RWY 28L GP OTS WEF 1306011400-1308222359
ISFO 06/004 SFO NAV ILS RWY 28R GP OTS WEF 1306011400-1308222359
San Francisco airport (KSFO) always lands on runways 28L and 28R unless a winter storm blows through. With today's light winds and good visibility it is a near certainty that these runways will be in use. But decoding the two lines above (they are called NOTAMS, for Notices To AirMen) we find that the GlidePath (GP) is OuT of Service (OTS) for both runways. The When in EFfect (WEF) is from June 1, 2013 to August 22, 2013 at midnight. This is important because the aircraft cannot fly these approaches on autopilot in the way the pilots are used to.
Here is where we have to move into sensitive territory. (There will be more of these before we're done.) At the end of the article Terror on Jet, in The New York Times on Monday, July 8, we find these lines:
Some experts said that pilots often have little opportunity to practice landings without the aid of such technology . . .
Still, given that the weather was ideal and the guide lights (PAPI, or Precision Approach Path Indicator) were on, making a visual landing should not have been difficult for most commercial pilots . . .
on a difficulty scale of 1 to 10, this was a 2 or 3 at the most . . .
A pilot's most important skill is his judgment. (see my Developing Pilot Judgment) He must look at the tasks and maneuvers ahead and ask two questions: Can the airplane do it? and Can I do it?
The former is mostly hard data in the Aircraft Flight Manual Limitations section, but it is also practical knowledge of what the aircraft's systems can and can't do and an understanding of the feedback systems that tell the pilot if the job is being done. (A good example is the AutoThrottle).
The latter question is the more important of the two: Can I do it? The only way to answer is through experience, and it is not measured in flight hours.
Training: have I been trained in this maneuver?
Practice: have I practiced it on my own? What were the results?
Recency: have I done one in the last 30 days? 90 days?
When Asiana's pilots were preparing for the flight in Seoul, the two NOTAM lines about the glidepaths on 28L and 28R should have triggered a dialogue:
“We're going to have to do an everything-off visual approach in KSFO. Has any of us been trained for this? Who has practiced one in the last year? Which of us has done one in the last 30 days? 90 days?”
I'd be willing to bet (I'll back this up in future installments) that none of the four pilots had flown a visual approach in the last 90 days. In that case, pilots with sound judgment would never have attempted the visual approach to 28L in KSFO. They would have diverted to Sacramento where there were long runways with functioning ILS systems.
Next: what else they did wrong . . .