- The pilots of last month’s doomed Lion Air Flight JT610
fought in a life-or-death tug-of-war with a malfunctioning
automated flight system, data from the flight’s black box
reviewed by the New York Times show.
- That struggle to keep the plane from nosediving ended when
the almost new Boeing 737 Max hit the Java Sea so hard some parts
disintegrated on impact.
- The new insights seem to suggest the pilots were unaware how
— or unable — to take the necessary steps to override the
The New York Times is reporting a harrowing breakthrough in the
investigation into the crash of the Lion Air Boeing 737 Max
8 that fell into the Java Sea in October, killing all 189
people on board.
Flight data taken from a recovered black box prepared by
Indonesian air crash investigators for release on Wednesday, was
reviewed by The New York Times.
The data reveal how hard the two pilots battled to stay in the
air and the difficulties they faced in dealing with what may have
been a rogue automated system. The data are also consistent with
the investigator’s main lead that the Boeing system installed on
its latest generation of 737s to prevent the plane’s nose from
getting too high and causing a stall actually forced the nose
down because of incorrect data sent from sensors on the fuselage.
According to information gathered from the aircraft’s flight data
recorder — the black box — JT610 was repeatedly pushed into
a dive position thought to be due to the automated system’s
malfunctioning sensors, a fault that began moments after take
From the moment the wing flaps were retracted at 3,000 feet, the
two pilots fell into a life-and-death tug-of-war against a new,
automated anti-stall system that is reportedly not
even referred to in the cockpit manual of the 737 Max 8.
With the readings on the 737 Max incorrect even as the
packed jetliner taxied out, once JT610 Max 8 was airborne, the
pilots control column began to shake as the precursor to an
imminent stall. Over the next 13 minutes of the plane being
airborn, a back-and-forth between the pilots and the system may
have happened more than 24 times as the pilots sought to retake
control before the Lion Air flight plummeted into the sea at 450
“The pilots fought continuously until the end of the flight,”
said Capt. Nurcahyo Utomo, the head of the air accident
subcommittee of the Indonesian National Transportation Safety
Committee. Nurcahyo said that in the case of Lion Air Flight
JT610, the stall-prevention system had been activated and is a
central focus of the investigation, according to The Times.
“If the pilots of Lion Air 610 did in fact confront an emergency
with this type of anti-stall system, they would have had to take
a rapid series of complex steps to understand what was happening
and keep the jetliner flying properly. These steps were not in
the manual, and the pilots had not been trained in them,”
Ahead of these latest revelations, we haven’t learned that much
about what happened aboard JT610 for those desperate 13
Fight for control
Already under investigators’ heavy suspicion is
the maneuvering characteristics augmentation system, or
MCAS, Boeing’s new anti-stall system
Boeing and the Federal Aviation Administration
directives earlier in November telling flight crews about the
system, which is designed to provide extra protection against
pilots losing control through lifting the nose and stalling the
Boeing’s has since said that its safety bulletin was only meant
to reinforce existing procedures.
In an internal email sent to Boeing employees, Chief executive
Denis Muilenburg defended his company’s development and
deployment of the Max-generations’ MCAS.
According to the Allied Pilots
Association, many aviators, unions, and flight-training
departments have said that none of the documentation including
pilot’s manuals for the Max 8 included an explanation of the
The MCAS is meant to stop pilots from angling the aircraft nose
too high which can affect the plane’s speed and lift and cause a
stall. It does this by automatically steering the nose of the
plane downward if it senses a stall is possible.
On this occasion, while JT610’s captain responded to each
nose-down movement by pulling the nose up again, the difficult
question remains: why didn’t the pilots just switch off the
flight-control system, which is thought to be exactly what the
on the previous day’s flight had done when they had
encountered a similar problem?
According to a memo Boeing sent to pilots and customers a week
after the crash, the system can suddenly push the nose so far
down that pilots cannot lift it back up.
manufacturer has vehemently denied withholding relevant
information about the system following the crash, but Boeing
has come under criticism for its lack of training and preparation
on the subject.
The system, it said, would kick in even if cockpit crews are
flying a plane manually and wouldn’t be anticipating a
computerized system to take over.
Earlier this month, Lion Air’s operational director Zwingli
Silalahi, said the manual failed to sufficiently inform pilots of
the MACS behaviors.
“We don’t have that in the manual of the Boeing 737 Max 8,”
Zwingli said Wednesday.
Boeing has said that the proper steps for pulling out of an
incorrect activation of the system were already in flight
manuals, so there was no need to detail this specific system in
the new 737 jet. In a
statement to the Times on Tuesday, the plane manufacturer
said it couldn’t discuss the matter due to the ongoing crash
investigation, but “the appropriate flight crew response to
uncommanded trim, regardless of cause, is contained in existing
The fact is, while the findings detailed for the Indonesian
Parliament is more than what was known before, much
remains unknown about the doomed flight, including why a plane
with apparently problematic sensors was even allowed off the
Investigators have yet to recover the cockpit voice
recorder, which could explain what steps if any the duo took to
regain control of the plane and why, moments before the final
dive, the captain handed control to the co-pilot.
A complete account of faults with the sensors on the fuselage,
referred to as “angle-of-attack sensors,” is now thought to be
part of the full report by Indonesian investigators.
One of those sensors was replaced before the plane’s next-to-last
flight after the jet experienced malfunctioning data readings,
Indonesian officials have questioned the role of faulty
airspeed indicators as they investigate the deadly Lion Air
but safety experts say pilots should be able to deal with
Indonesia’s transport ministry, earlier
this month, issued a 120-day suspension to Lion Air’s
maintenance and engineering directors, its fleet maintenance
manager, and the engineer who gave the jet permission to