Subject: Asiana 214 - An uncorrected high
visual descent path led to an unstabilized approach
Jim,
Interesting, but the problem remains that they were high all the
way in.
The FMS (Flight Management System) displays distance from the
runway – the pilot should have been constantly monitoring the target visual
descent profile. For example, using the standard 300 feet per mile profile, at
5 miles from the runway his altitude should have been about 1500 ft. The flight
profile shows that he was over 2200 feet. This is an extremely high descent
path, and very difficult to correct inside 5 miles, yet he apparently did
nothing to correct it until he was less than 2 miles from the runway. At that
point, he had to close the throttles to get down to the slot altitude for
landing in the touchdown zone, probably by disconnecting the auto-throttles.
This (closing the throttles) is very dangerous that close in, given the
extremely high drag configuration. He immediately got into a high sink rate,
and let the airspeed bleed off. He was over 30 knots below bug speed (known as
Vref). Even five knots below bug is absolutely unsatisfactory and unacceptable.
It is grounds for automatic failure on a check ride, either a simulator or line
check ride.
Again, this is a classic picture of a pilot who has weak basic
flying skills, was way behind the aircraft, and was relying entirely too much
on the auto-flight system.
It is very difficult to manage the auto-flight system to correct
an extreme off-descent path situation. It typically deteriorates into a frenzy
of button pushing which takes the focus off the basic flight instruments
(airspeed, altitude, pitch/roll attitude). The proper and safest technique is
to take over manual control to re-establish a normal descent path, then
re-activate the auto-flight system if that is desired. However, in this case it
was so close in that the safest and best alternative would have been to
continue manual flying to the landing.
The visual descent path should have been corrected at ten miles
out, no more than five miles out. When that was not done, an unstabilized
approach was almost inevitable.
This is a tragic and needless accident. I continue to believe
that Asiana Airlines, and probably Korean Airlines as well, should be grounded
until the proficiency of every single pilot flying for those airlines can be
verified and documented by an outside agency.
Dave
Using
radar data from FlightAware, I plotted the altitude and airspeed of AAR214,
as well as that of UAL852, another 777 which landed successfully only 10
minutes beforeAAR214. Both flights were long distance international flights
(UAL852 originated at Heathrow, London), probably both full of people but
without much fuel, so both aircraft would have had more or less the same weight
on landing, and therefore the same reference approach speed, V ref . It's instructive to
compare the landing profile of these two flights. The first plot below is the
altitude vs. distance from the touchdown zone for both aircraft. UAL852 is in
black, and AAR214 is in red.
From: XXXX
Sent: Thursday, July 11, 2013 4:22 AM
To: David LaRocque
Subject: FW: Asiana 214 / Korean airline training culture
Sent: Thursday, July 11, 2013 4:22 AM
To: David LaRocque
Subject: FW: Asiana 214 / Korean airline training culture
Dave,
FYI: From my friend (and former Team-mate) Harry Butler, who flew many years
for Gulfstream. Jim
-----Original
Message-----
From: XXXX
Sent: Wednesday, July 10, 2013 8:54pm
To: XXXX
Subject: Asiana 214 / Korean airline training culture
From: XXXX
Sent: Wednesday, July 10, 2013 8:54pm
To: XXXX
Subject: Asiana 214 / Korean airline training culture
Spaceman,
One big assumption everyone makes is that
this guy was flying the 777. Our company designed the Avionics suite the Boeing
uses and the whole system, with all the automation, is for the FGCs(Flight
Guidance Computers) to do all the flying not the pilot.
In the big scheme of things the pilots
program the IFR Arrival, Approach and Runway into the FMS(Flight Management
System) and it does everything else. We don't even touch the throttles till
after touchdown and deploy the buckets.
I've flown into KSFO a gaggle of times, my
guess is that they were on the Quiet Bridge arrival for a long lazy almost
straight in approach to the duty runway. Everything was coupled to the FMS +
Auto-throttles then when they got in close the decision was made to disconnect
the FGCs and hand fly it. That's when the shit hit the fan. You got my previous
email about how fucked up lots of foreign air carriers are.
HB
1 comment:
back in the early 70's there was a similar landing by a JAL pilot. I read about it in a self-help booklet. The story went like this.:
The JaL flight made his approach and everything was great. At the inner markers the Tower began to suggest he raise up a bit. Then to insist and finally to scream. In the end the JAL flight landed in tact 250 feet in the bay. The passengrs got on the rubber boarts and the plane was towed to shore and dragged ashore on its gear. The Pilot was Cpt Ah Soo was told to shut up by the Airlines lawyers. He moved into a suit in the Hotel and was incommunicado.
The press went bonkers. The FAA established a tribunal. thousands of technicians. Hundredfs of parts suppliers, and a few dozen expert pilots were hired for input tot he NTSB investigators.
The day of the first tribunal meeting they had 20 or so opening remarks. Then they swore in the pilot so he was under oath in both English and Japaneese.
The small man stood up as photo shot were taken and placed his glasses on his face. He looked straight at the tribunal.
The Tribunal leader asked him to explain exactly in his own words led to the plane l;anding in the bay.
The answer never made the paper!
He said in perfect english as his lawyers and the tribunal googled him wide eyed.
"Ah Soo Fucked up!" He then sat down and the Tribunal and all those people went home. Cpt Ah Soo was sent to fly in Asia and no one ever mentioned the expense again.
So what did the Capt Say this time???
Post a Comment