Jakarta havariet - AW&ST går igjennom hendelsesforløpet i detalj - AW&ST og Curt Lewis

Lion Air Interim Report Highlights Confusion And Dysfunction Sean Broderick and Adrian Schofield A preliminary report on the Lion Air Flight 610 (JT610) accident investigation sheds little new light on why the pilots did not keep the hard-to-control aircraft from entering its final, fatal dive. But it confirms that familiar procedures being reemphasized to pilots for managing uncommanded nose-down events caused by the aircraft’s new automatic pitch trim protection system—including flipping two switches—had worked for a different crew on the aircraft’s previous flight. Investigators also underscore that the aircraft was not airworthy for at least its last two flights, which points to possible gaps in the airline’s maintenance practices and safety culture. Determining whether the JT610 crew recognized the specific problems their Boeing 737-8 was experiencing and what procedures they followed during their 11-min. flight Oct. 29 will be difficult without recovering the aircraft’s cockpit voice recorder (CVR). The revelation that the automatic stabilizer trim cutout switches worked on the previous flight suggests one explanation—faulty switches—for the inability to stop the automatic nose-down commands is unlikely. Investigators issue interim update on Lion Air 610 probe Pilots faced several failures, but what they understood is unclear Aircraft was unairworthly on previous flight, never repaired Information in Indonesia’s National Transportation Safety Committee (NTSC) report lends further credence to the theory that the JT610 crew became confused and perhaps overwhelmed as they struggled to keep their aircraft’s nose up. The crew faced immediate problems during their scheduled flight from the Indonesian capital of Jakarta to Pangkal Pinang, including disagreeing angle-of-attack (AOA) indicator vanes. The left AOA vane’s value was 20 deg. higher than the right’s from the start of the flight, so the left vane told the aircraft’s related systems that the nose was too high. This caused a left-side control column stick-shaker stall warning as the aircraft rotated. The aircraft’s airspeed indicators also disagreed. As soon as the flaps retracted, the aircraft’s automatic trim system—apparently the Maneuvering Characteristics Augmentation System (MCAS) flight-control law added to the MAX family to help it handle like 737NGs, but the report does not reference MCAS specifically—applied nose-down trim for 10 sec. The pilots countered by pulling back on the yoke to counteract the unneeded nose-down movement. At least 25 of these exchanges took place during the rest of the flight. The last automatic nose-down input precipitated a dive from about 5,000 ft. that ended with the aircraft hitting the Java Sea. All 181 passengers and eight crewmembers died. “We won’t really know more until we have the CVR recording, but it seems they either didn’t realize the aircraft was trimming against them, or they didn’t realize they could stop it with the cutout switches,” says one 737 pilot with experience on the MAX family, adding the combination of failures may have confounded the crew. “A stick-shaker is a big deal and attention-getting, confounded by the erroneous airspeed indications,” the pilot explains. “The most insidious problem is the trimming, however, which could go unnoticed with the stick-shaker activating. The extended forward trim makes the aircraft much more difficult to control. If you realize what is going on and take steps to address it, this shouldn’t be that hard to handle, but it could be a very confusing and challenging situation close to the ground.” The NTSC report also reveals Lion Air was immediately concerned about the possibility of uncommanded stabilizer inputs playing a role in the accident. Within hours after JT610 disappeared, the airline’s “Safety and Security Directorate issued [a] safety reminder to all Boeing 737 pilots to review several procedures including memory items of Airspeed Unreliable and Runaway Stabilizer,” the NTSC report says. Using the cutout switches is one of the steps on the Runaway Stabilizer checklist, and following is one of several emergency procedures considered “memory items,” meaning pilots should know them, step-by-step, without having to look them up.

Investigators are still searching for key parts of the Lion Air 737-8, including the cockpit voice recorder. Credit: Ulet Ifansasti/Getty Images

The JT610 first officer (FO) told air traffic controllers the crew was battling “flight-control problems,” and asked the controllers to verify altitude and airspeed readings because the aircraft’s instruments were not reliable. While these early clues likely played a role in Lion Air’s unusually specific reminder to pilots so soon after an unexplained accident, issues with several previous flights also hinted at what the JT610 crew may have faced. Pilots reported a series of technical faults with the three-month-old aircraft, PK-LQP, during four flights over three days before the JT610 accident. Among them: AOA, altitude and airspeed sensor disagreements between the pilot’s and the FO’s instruments. Maintenance was performed each night, and ground tests determined the aircraft was airworthy. During PK-LQP’s prior flight on Oct. 28 from Denpasar to Jakarta, “the stick-shaker activated during the rotation and remained active throughout the flight,” the report says. The pilot noticed an “IAS [indicated airspeed] disagree” warning, and that the aircraft was automatically trimming nose down. This was most likely caused by the MCAS. During the next 8 min., the pilots analyzed the problem. They determined that any effort to manually readjust trim and pull the nose up resulted in automatic nose-down commands. The crew followed three nonnormal checklists (NNC): Airspeed Unreliable, Alt Disagree, and—critically—Runaway Stabilizer. At one point, the pilot moved the stabilizer trim switches to “cut out”—one of the Runaway Stabilizer checklist’s last-resort items—and the trimming stopped. He then flipped them back, “but almost immediately the problem reappeared,” says the report on the prior flight. The pilot moved the switches back to “cut out,” and the crew conducted the rest of the flight with manual-trim inputs. When the problems started, the crew appeared to consider diverting. The pilot declared a “PAN PAN”—or urgent situation but not yet an emergency. A controller asked if the flight needed to return to Denpasar, and the pilot responded, “Stand by.” But once the automatic trimming stopped and the aircraft was controllable, the crew decided to continue the flight, because none of the checklists the pilot referenced “contained the instruction, ‘Plan to land at the nearest suitable airport,’” the report says. Following that flight’s arrival in Jakarta, the pilot filed an electronic report summarizing the issues, listing “Airspeed Unreliable” and altitude (ALT) disagreement. He also wrote that the aircraft’s speed-trim system (STS) was “running in the wrong direction.” The report does not say the pilot told mechanics he went through the Runaway Stabilizer checklist. Maintenance conducted following the flight included flushing the left-side pitot and static air data sensors to address the airspeed and altitude disagreements, the report says. A ground test showed the equipment was serviceable. The report does not reference any work or tests on the AOA sensor. A Nov. 10 message from Boeing shed more light on the MCAS, which many pilots did not know existed. It provides automatic nose-down input in certain manual flight profiles to help prevent stalls. The MCAS’ primary input is data from one of two AOA sensors. The system runs through the flight control computer (FCC) and alternates between using data from the aircraft’s left and right AOA sensors with each flight, but a full power-down/power-up of the aircraft will reset the system to take data from the left-side AOA. It does not operate when flaps are deployed. While the MCAS is new, its role as an aid to help trim the aircraft as well as its failure mode—uncommanded nose-down trim caused by incorrect data or an FCC anomaly—are well understood by pilots. Two other stall-protection systems on the MAX, STS and elevator feel shift, are identical to those on the NG. Because of this, Boeing’s focus since the accident has been reiterating that the procedures for stopping uncommanded trim remain unchanged from those for the NG. Many airlines have been updating their pilots with MCAS-related bulletins, while some have gone further. Germany’s TUI fly revamped its preflight briefing procedures to incorporate a review of the MAX family’s Runaway Stabilizer and Airspeed Unreliable checklists “on the first flight of the day and following a change of either pilot.” The NTSC report, which provided facts but no analysis or conclusions, includes several recommendations. One focuses on safety culture—specifically calling on Lion Air to ensure pilots follow the airline’s operations-manual requirement to discontinue a flight if unairworthy conditions occur. The stick-shaker condition during the Oct. 28 flight “is considered [an] unairworthy condition and the flight [should not have] continued,” the report says. Another recommendation calls for better flight documentation, since there was one more flight attendant on board than listed on the weight-and-balance sheet. It also acknowledges actions taken by Boeing, Lion Air and regulators based on what has been learned. Boeing responded to the report’s release with a statement saying it is “taking every measure to fully understand all aspects of this accident, working closely with” investigators and regulators. The manufacturer called attention to ineffective troubleshooting in the days before the accident, noting maintenance logs “recorded problems related to airspeed and altitude on each of the four flights that occurred over the three days prior to Flight 610.” The logs “indicate that various maintenance procedures were performed, but issues related to airspeed and altitude continued on each successive flight,” Boeing points out. The airframer also highlighted the pilots’ actions during the Oct. 28 flight, noting they seemingly faced the same problems as the JT610 crew, and “turned off the stabilizer trim switches within minutes of experiencing the automatic nose-down trim.” The Oct. 28 crew followed checklists as “the appropriate procedure to address unintended horizontal stabilizer movement, regardless of source,” Boeing adds. The Runaway Stabilizer checklist does not discuss why the condition may happen. It only provides increasingly aggressive troubleshooting steps to stop it. The JT610 crew “experienced issues with altitude and airspeed data that the pilots had previously experienced on the earlier flights, due to erroneous AOA data,” Boeing continues. However, “unlike as is stated with respect to the prior flight, the report does not state whether the pilots performed the Runaway Stabilizer procedure or cut out the stabilizer trim switches.” How Pitch Played Out on JT610 and the Aircraft’s Previous Flight Investigators released depictions of key digital flight-data recorder (DFDR) parameters from Lion Air Flight 610’s (JT610) accident on Oct. 29 and the aircraft’s previous flight the day before. On both flights, the aircraft’s two angle-of-attack (AOA) sensors disagreed, and faulty data from the left-side sensor showed the aircraft was approaching a stall. The aircraft’s flight-control computer (FCC) responded by commanding nose-down inputs, depicted by the orange lines on the charts below. On each flight, pilots responded by pulling back on control columns to counteract the nose-down inputs manually, as depicted in light blue on these charts. But the system continued to detect inaccurate data from the AOA sensor, reactivating the FCC’s automatic nose-down commands.

Source: Indonesia National Transportation Safety Committee

During the Oct. 28 flight (see chart above), the pilots executed several checklists, including Runaway Stabilizer. That checklist includes a item that calls for toggling two “cutout” switches that stop the automatic trim. The pilot toggled the switches, and the trim stopped. He then flipped the switches back on, causing one more cycle of automatic nose-down input and manual response. He quickly toggled the switches off, and left them off for the remainder of the flight.

Source: Indonesia National Transportation Safety Committee

Investigators have not said what, if any, troubleshooting procedures the JT610 crew followed, in part because the aircraft’s cockpit voice recorder—which would help illustrate what the pilots were experiencing and how they reacted—has not been recovered. The DFDR depicts (see chart above) a near-continuous cycle of automatic nose-down inputs (orange line), followed by manual nose-up responses (light blue) throughout the 11-min. period from just after rotation to impact. On each flight, the automatic inputs appeared to start with the flaps retracted just after liftoff. During the accident flight, the only period of sustained interruption was when the crew extended the flaps. The automatic inputs were apparently commanded by the Maneuvering Characteristics Augmentation System (MCAS) flight-control law added to the 737 MAX family to help it handle like 737NGs, but the report does not reference the MCAS specifically. The MCAS’ triggers include data from either the left or right AOA input, with the source alternating after each flight. Following a power down/power up of the aircraft, the system starts with left-side AOA input. Boeing says that while the MCAS is a new augmentation to the flight control system, its presence does not change troubleshooting procedures for a Runaway Stabilizer scenario. In a statement on the preliminary accident report, Boeing pointed to the Oct. 28 crew’s successful troubleshooting process when faced with uncommanded nose-down inputs. EXCLUSIVE-Boeing eyes Lion Air crash software upgrade in 6-8 weeks By Eric M. Johnson and Tim Hepher SEATTLE/PARIS, Nov 29 (Reuters) - Boeing Co BA.N is weighing plans to launch a software upgrade for its 737 MAX in six to eight weeks that would help address a scenario faced by the Lion Air crew during last month's deadly crash in Indonesia, two people briefed on the matter said on Thursday. Crash investigators are focusing on the possibility that a new anti-stall system that repeatedly pushed the Lion Air jetliner's nose down was being fed by erroneous data from a faulty sensor left in place after a previous hazardous flight. Boeing has said cockpit procedures that were applied on the previous flight are already in place to tackle such a problem, and that its 737 series remains safe to fly. But U.S. regulators have said Boeing is also examining a possible software fix, after coming under fire for not outlining recent changes to the automated system in the manual for the 737 MAX, the latest version of its best-selling passenger jet. While plans for the possible fix are not final, Boeing's software upgrade could block the recently modified anti-stall system, known as MCAS, from continuously running until the plane hits its nose-down limit, the sources said. The MCAS function would be disabled if the crew counteracted it by trimming or adjusting settings in the opposite direction, according to two people briefed on Boeing's proposals. "When the crew makes the adjustment, that would essentially disengage MCAS unless it got new data," one of the people said. Data from the Lion Air flight recorder suggests the pilots sought to correct the system more than two dozen times before the jetliner plunged into the Java Sea on Oct. 29, killing all 189 people onboard. Attention has focused on the role of a suspect "angle of attack" sensor used to drive alerts on stall or loss of lift. While each 737 has two of these blade-shaped vanes, the plane's anti-stall system relies on data pulled from just a single vane during each flight, compared with a three-sensor "voting" system on rival Airbus AIR.PA jetliners. Boeing's software update would come as an emergency measure from Boeing and Federal Aviation Administration, the sources said. SECOND PROBE The specific system for preventing stalls was not originally designed to monitor both probes because regulators assumed risks of a mishap were small and would be further reduced by the presence of a trained crew and power switches on errant systems. Now, however, Boeing is examining whether the anti-stall system should also check data from the second probe before engaging, according to a person briefed on the matter. Boeing declined comment on the proposed changes. "As part of our standard practice following any accident or incident, we examine our aircraft design and operation, and when appropriate, issue bulletins and make recommendations to operators to further enhance safety," a Boeing spokeswoman said. "Boeing continues to evaluate the need for software or other changes as we learn more from the ongoing investigation." The FAA has repeatedly said it will "take further action if findings from the accident investigation warrant." A decision to update the software has not been finalised and Boeing could choose a different strategy, the people said. The world's largest planemaker has 4,542 of the upgraded 737 MAX on order from airlines, worth over half a trillion dollars at list prices, or about half that after typical discounts. Boeing has delivered 241 of the jets to customers since it entered service last year, according to its website. (Reporting by Eric M. Johnson in Seattle and Tim Hepher in Paris; Additional reporting by Tracy Rucinski in Chicago, David Shepardson in Washington and Jamie Freed in Singapore; Editing by Lisa Shumaker) Back to Top US Pilots Want More Training on New Boeing Jet After Crash US airline pilots are asking for more training around an automated system suspected of playing a role in a deadly crash in Indonesia. FILE- In this Nov. 14, 2018, file photo a Boeing 737-MAX 8 is parked outside Boeing Co.'s 737 assembly facility in Renton, Wash. Southwest Airlines says its pilots will get more instruction on an automated anti-stall system on certain new Boeing jets, and American Airlines pilots are also seeking more training. The system is under scrutiny after a deadly crash in Indonesia. The developments came Thursday, Nov. 29, after Boeing technical experts met separately with pilots from both airlines. (AP Photo/Ted S. Warren, File) THE ASSOCIATED PRESS DALLAS (AP) - Southwest Airlines says its pilots will get more instruction on an automated anti-stall system on certain new Boeing jets, and American Airlines pilots are also seeking more training. The system is under scrutiny after a deadly crash in Indonesia. The developments came Thursday after Boeing technical experts met separately with pilots from both airlines. Indonesian investigators are probing whether pilots on an Oct. 29 Lion Air flight were overwhelmed when incorrect sensor readings activated the anti-stall system and automatically pushed the nose of their plane down. The Boeing 737 MAX plunged into the Java Sea, killing 189 people. The anti-stall system differs from those in previous Boeing 737 models. Pilots at American and Southwest say Boeing didn't explain the changes in the new plane's operating manual. Boeing says the MAX is safe and that there is a procedure for stopping the nose-down command. The Chicago-based company, however, is considering whether software changes in the anti-stall system are needed. Modern planes use sensors outside the fuselage to measure airspeed and the pitch of the plane's nose. The sensors can malfunction, however, and safety experts have suggested that Boeing will have to change the automated anti-stall system of the 737 MAX - which entered service last year - to prevent it from responding to a single erroneous reading. Southwest Airlines said all of its pilots will get additional classroom and simulator training by the end of the year. Airline spokeswoman Brandy King said the training will include recognizing and reacting to situations in which the nose might be pointed too high, and unreliable sensor readings. Boeing representatives met Sunday with leaders of the pilots union at Southwest. The union declined to comment on the meeting. Dennis Tajer, an American Airlines pilot and spokesman for the Allied Pilots Association, said several members of his union met with Boeing's lead engineer and chief test pilot for the 737 MAX on Tuesday in Fort Worth, Texas. He said they quizzed the Boeing experts on how erroneous readings from a single sensor could trigger the nose-down command. American Airlines pilots who were already familiar with the 737 got 56 minutes of training on a tablet computer when learning to fly the MAX, and "it seemed to suffice," said Tajer, who is a pilot himself, "but clearly there is more to this aircraft." A Boeing spokesman said the company always examines aircraft design and operation after any accident or incident. "Boeing continues to evaluate the need for software or other changes as we learn more from the ongoing investigation," said the spokesman, Charles Bickers. A spokesman for American declined to say whether the airline had agreed to the union's request for more training, saying only that the airline was working with the union. United spokeswoman Megan McCarthy said, "We have the proper training in place for our pilots." At the end of October, Southwest had 26 Boeing 737 MAX jets, American had 16, and United Airlines had seven, according to Boeing figures. https://www.usnews.com/news/business/articles/2018-11-29/us-pilots-want-more-training-on-new-boeing-jet-after-crash Back to Top Boeing CEO addresses flight system update after criticism from pilots "Regardless of the outcome, we're going to learn from this accident and continue to improve our safety record," Muilenburg told employees in an internal memo. In an internal memo sent to employees last week, Boeing chief executive Dennis Muilenburg reiterated the safety record of the company's 737 commercial jetliner. (Richard Drew/AP) Boeing executives have sought to assuage concerns of pilot groups and customers in the weeks since a new Boeing 737 Max 8 crashed off the coast of Indonesia, even as an investigation into the cause of the crash remains inconclusive. In an internal memo sent to employees last week, Boeing chief executive Dennis Muilenburg reiterated the safety record of the company's 737 commercial jetliner, which he described as "a safe airplane designed, built and supported by skilled men and women who approach their work with the utmost integrity." He pledged to continue to improve safety processes. "Regardless of the outcome, we're going to learn from this accident and continue to improve our safety record," Muilenburg wrote. The company is grappling with the fallout of an Oct. 29 disaster in which a Boeing 737 Max 8 operated by Indonesian budget airline Lion Air crashed into the Java Sea shortly after takeoff from Jakarta, killing all 189 people on board. Pilot groups have said they were "kept in the dark" about an update to the plane's automated safety system. The Boeing 737 has gone through multiple iterations and upgrades since it first flew in 1967. Its newest model is the 737 Max. When Boeing repositioned the engines on the Max and made them more powerful, it introduced a system called MCAS (Maneuvering Characteristics Augmentation System) that was intended to make the airplane behave identical to its predecessor, the 737 Next Generation. Given that intention, Boeing told the airlines about MCAS, but pilots say it wasn't included in their training. It remains unclear whether Lion Air's 737 operated as Boeing expected it would. Boeing notified pilots in a Nov. 6 advisory that a manual override feature of earlier 737 models would not work on the Max 8, but Boeing representatives have not answered questions about when the company first became aware of that change. It's also unclear why it was not addressed in pilot training. "Listening to pilots is a critical part of our work," a Boeing spokeswoman said. "Their experienced input is front-and-center in our mind when we develop airplanes." The 737 in the Lion Air crash had experienced a problem on the flight into Jakarta in which the displays for the pilot and the co-pilot showed different information, according to a preliminary report released this week by Indonesian investigators. That problem on the day before the fatal flight was addressed by engineers overnight, but apparently wasn't resolved. After the Lion Air crash, Boeing issued a bulletin to airlines that said faulty airspeed indicators could "trim the stabilizer nose down in increments lasting up to 10 seconds." Though the investigation is ongoing, it appears the pilots on the doomed flight were fighting the MCAS, which interpreted faulty input from an airspeed indicator to mean the plane was in a stall from which it might not recover unless immediate action was taken. The MCAS responded by directing the nose down. "Does this mean the MCAS and other flight programs are unable to resolve discrepancies between the left and right seat flight displays, and isn't that a terrible design flaw?" said Mary Schiavo, an aviation lawyer and former inspector general of the U.S. Transportation Department. "The computer can't reconcile the difference, or permit the [co-pilot] to fly normally from the right seat when there is a problem" with the pilot's control display. A preliminary report released Wednesday by the Indonesian National Transportation Safety Committee (NTSC) detailed the chaotic final minutes of the flight. According to the report, pilots fought to keep the plane level as it repeatedly steered toward the sea. It is not clear whether the pilots attempted a "runaway stabilizer" procedure that would have overridden the plane's automated system. Black box data released by investigators showed pilots were pulling back on the control column in an attempt to raise the plane's nose, applying almost 100 pounds of pressure to it. The report stopped short of assigning blame for the crash. A summary presented to reporters Wednesday by the NTSC noted that the report had recommended Lion Air "improve the safety culture" while also "ensuring that all operation documents are properly filled and documented." Muilenburg referred to the crash as "a tragic accident." He said Boeing's employees have been "pouring significant energy into actively supporting the investigation and our MAX customers." A Boeing spokeswoman said Thursday that the company regularly communicates with airlines and pilots but has "stepped up that engagement" in recent weeks, including "reinforcement of appropriate existing procedures" relevant to the situation investigators have described in Lion Air Flight 610. "Every day, millions of people rely on our commercial airplanes to crisscross the globe safely and reliably," Muilenburg told employees. "When that doesn't happen, for any reason, we take it seriously." Pilot union representatives say they have met with Boeing technical experts about the 737 safety features. Allied Pilots Association communications committee chairman Dennis Tajer said a group of Boeing representatives, including a high-level engineer and a company test pilot, met with APA pilots at the association's headquarters in Fort Worth on Tuesday. Jon Weaks, president of the Southwest Airlines Pilots Association, said the company held a similar meeting in Reno, Nev., on Sunday. A Boeing representative declined to comment on the meetings. "As far as I know, it was the first time that a manufacturer had reached out to SWAPA directly," Weaks said. "We appreciated it, and we were disappointed we didn't know about MCAS before, but at a certain point you have to move forward." Also in the memo to employees, Muilenburg asserted that the company had not withheld information from customers. "You may have seen media reports that we intentionally withheld information about airplane functionality from our customers. That's simply untrue," Muilenburg wrote. "The relevant function is described in the Flight Crew Operations Manual, and we routinely engage customers about how to operate our airplanes safely." Customers and their passengers, a Boeing spokeswoman said, "have our assurance that the 737 Max is as safe as any airplane that has ever flown the skies."