GDR

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GDR last won the day on May 20 2017

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About GDR

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  1. Speaking from a position of ignorance on this subject, (a position in which I have a great deal of experience), is it correct that if this occurs and the pilot knocks off a couple of switches, disarming the MCAS and the problem goes away?
  2. I don't think this has been posted before. Enjoy Greg
  3. A New York Times investigation of the Oct. 29, 2018, Lion Air Boeing 737 MAX crash suggests marketing considerations were at least partly behind Boeing’s and the FAA's joint decision to not specifically train pilots in the maneuvering characteristics augmentation system (MCAS) that may have played a role in the crash. The Times story quotes various named sources as saying that Boeing wanted to maintain the cross compatibility between the new aircraft and earlier versions of the 737, thus simplifying conversion training and reducing costs for airlines buying the MAX. The difficulty was that the physically larger engines that accomplish the plane’s main selling point—better fuel economy—had to be mounted higher and farther forward than on its predecessors and that significantly changed low-speed flight characteristics. MCAS was designed to compensate for the MAX’s increased tendency to stall in a low-speed turn by adjusting the angle of the horizonal stabilizer. The system takes data from one of two angle of attack indicators (there’s no redundancy or agreement requirement) and was designed to automatically push the nose down if an incipient stall was detected. Boeing convinced the FAA that because the system maintained the basic flight characteristics of earlier versions that pilots did not need specific training on MCAS even though its inclusion was considered necessary for certification of the aircraft. The Times story also notes that other regulators at least initially determined that pilots should be made aware of MCAS. European regulators wanted pilots to be trained on it but eventually accepted the FAA’s and Boeing’s position. Brazil, however, stuck to its guns and required specific training for pilots on MCAS. Boeing didn’t hide the addition of MCAS. It’s described in operation and maintenance manuals and was explained in technical briefings with prospective customers. It also included an emergency checklist covering disabling the system. But because they were not specifically trained in its use, most pilots didn’t know it was there and that it operated fundamentally differently from the speed trim system that operated the stabilizer setting on earlier 737s. Notably, pulling back on the yoke on older aircraft disables the automatic trim. Pulling back does not deactivate MCAS on the MAX. Something the Times couldn’t determine was whether MCAS was tested in a failure mode, either in the simulator or on the aircraft itself. The predominant theory on the root cause of the crash was that faulty AOA data resulted in an erroneous and extreme reaction from the MCAS, pushing the aircraft into a high-speed dive that the pilots could not recover from. Boeing and the FAA are under investigation by the National Transportation Safety Board and Indonesian authorities to determine if the decision to skip pilot training in the new system played a role in what became the worst air crash of 2018. https://www.avweb.com/avwebflash/news/Boeing-FAA-Probed-In-Lion-Air-Crash-232225-1.html
  4. They have the voice recorder. https://www.ctvnews.ca/world/indonesia-finds-lion-air-jet-cockpit-voice-recorder-1.4252009
  5. Just a foot note to that, and just a reminder to Kip, 435 was always first.
  6. By Tim Hepher PARIS, Jan 3 (Reuters) - Airbus narrowed a sales gap against U.S. rival Boeing by finalising orders for 120 of the former Bombardier CSeries jet, but shares in Europe's top planemaker fell as doubts surfaced over a target for overall 2018 deliveries. Airbus, which took over the loss-making CSeries last July and rebranded it the A220, said on Thursday it had finalised deals to sell 60 each of the jets to U.S.-based JetBlue and to Moxy, a U.S. start-up backed by JetBlue founder David Neeleman. But shares in the European company fell as Airbus prepared a keenly awaited delivery tally for overall deliveries in 2018. In late trading they were down 3.6 percent. Reuters earlier reported growing doubts over whether Airbus had achieved a 2018 target of 800 deliveries, or 782 without counting the Canadian A220 jets. An industry source familiar with the matter said it was "more than likely" Airbus had missed the target by a handful of jets, marking the first time it has done so since it was reshaped through European mergers in 2000. An Airbus spokesman declined to comment. Deliveries are closely watched by investors since they mark the point at which most cash and operating profit are generated. Planemakers worldwide have been struggling with supplier problems in the past 12 months and Airbus has faced some production snags and quality problems, though any shortfall in deliveries is not expected to have a significant profit impact. Thursday's U.S. deals mark the first formal orders for the 110-130-seat A220 since Airbus took majority control of the Montreal-based programme with Bombardier and Quebec as partners. That realignment sets the stage for a broader confrontation with Boeing, which last month closed a deal to take over 80 percent of the commercial unit of Bombardier’s competitor Embraer, subject to Brazilian government approval. For 2018, most attention is on the core sales battle between the transatlantic plane giants, with Boeing so far in the lead. Airbus ended November with 35 percent of net sales in the main jetliner market against its U.S. rival after 11 months overshadowed by management changes and delivery delays. Since then it has picked up speed with formal deals for 220 aircraft, including a 100-plane order from Irish lessor Avolon, leaving it 90 short of Boeing's end-November total of 690 jets. On a like-for-like basis, excluding the former CSeries model, Airbus has reached a total of 480 net sales for the year against Boeing's most recent tally of 690 for a market share of 41 percent, based on orders announced since November. Airbus plans to give full-year figures on Jan. 11. Both companies often pull in last-minute deals to lift annual totals, with announcements delayed until early the following year. (Reporting by Tim Hepher; Editing by Mark Potter)
  7. Hi Kip It was an interesting experience flying into Alert. Our navigators were really accurate with our radar getting us lined up with the barrels at the end of the runway. Some even worked out a system where they could give us a verbal glide slope. Of course you could always get down low over the ice and fly straight in but you sure had to trust the nav you were with. I have pictures on my den wall of the Herc (321) that crashed up there as it was the airplane I was promoted to aircraft commander on. Thule was fun and they sure had a great PX. I brought back what was then a great stereo system from there. I remember the ropes between buildings to keep from from getting lost in the 20 feet or so that you had to traverse when one of the frequent storms hit. I also remember getting a few pretty rough rides going in there when the wind was coming from the direction of the flat top island to the left of the approach. Ah to be 24 again eh. Happy 2019 Greg
  8. This makes a little brighter end to a tragic event. https://newsinteractives.cbc.ca/longform/a-memory-of-sacrifice Happy 2019 to all AEFers Greg
  9. This is a great story and it would be nice to find the answer. https://www.cbc.ca/news/canada/toronto/air-canada-lost-family-1.4958126
  10. I look up from my computer and I'm looking over YYJ. I'll kinda miss seeing these old birds go by. https://globalnews.ca/news/4720681/sea-king-helicopters-retired/
  11. Received this. It summarizes the current situation as well as possible at this point IMHO. THE AOA PROBLEM WHAT WE CAN DO ABOUT IT By Captain Shem Malmquist AN FSI COMMENTARY Editor's Note: Thank you for your response to the many articles we have published in the wake of the Lion Air 610 crash. This one suggests a hopeful way forward that will benefit our industry. Captain Malmquist's analysis offers the perspective of a veteran line pilot and accident investigator who is also the coauthor of a book we recently co-published, Angle of Attack. As always FSI welcomes your comments on this important issue. In the wake of the October 29 Indonesian crash of a brand new Boeing 737 MAX 8 that took the lives of 189 passengers, the FAA has issued Emergency Airworthiness Directive (AD) 2018-23-51. The 737 is the most widely flown aircraft in the world, This tragedy opens an important conversation between regulators, operators and pilots. Lion Air, an experienced 737 operator, was the launch carrier last year for the 737 MAX 8 and the MAX 9 in March. While it will take a long time to analyze the Lion Air 610 accident, the AD points out that current system architecture has created vulnerabilities. Anyone who flies modern jet aircraft, as I do, also knows that in some ways this conversation applies to every plane and every pilot. Attempts to assign blame to anyone at any point in this investigation sidesteps a much more important issue, one that is the essential to the future of ever more automated cockpits. The FAA says its AD was "prompted by analysis performed by the manufacturer showing that if an erroneously high single angle of attack (AOA) sensor input is received by the flight control system, there is a potential for repeated nose-down trim commands of the horizontal stabilizer[1]. This condition, if not addressed, could cause a flight crew to have difficulty controlling the airplane, and lead to excessive nose-down attitude, significant altitude loss, and possible impact with terrain[2]." As described in the Seattle Times, "The system called MCAS, for Maneuvering Characteristics Augmentation System, is activated when a sensor on the side of the fuselage indicates a dangerously high angle of attack (AOA), the angle between the air flow and the wing. "If the plane is in an abnormally steep turn that puts high stress on the air frame, or when its speeds fall so low it's about to stall, MCAS will kick in and swivel the horizontal tail to push the nose of the airplane down in an effort to avert the danger".[3] While the Seattle Times article incorrectly implies that the system is based on speed or "high stress on the air frame, " the system description appears to be essentially correct. Low airspeed or a higher load factor (which can occur in a steep turn or pull up from a dive) are among the possible reasons the angle of attack can approach a stall. Unlike other critical components such as air speed indicators or altimeters which have comparator systems that cross check each other for spurious indications and alert the pilot that there is a mismatch, pilots have no way to quickly determine if they are being misled by a faulty AOA sensor[4]. As with erroneous airspeed or altitude readings, the loss of the sensor itself leads to loss of secondary systems and/or can trigger other warning systems. Even on the most advanced state of the art aircraft there is no direct feedback to the pilots when the AOA sensor itself has failed. Pilots must quickly infer a faulty AOA sensor from other faults or indications. Underlying this problem is the fact that a computer software system does not "fail" like a mechanical system. It can be incorrectly coded, or it can be incorrectly designed, but the system does not "fail" like a turbine blade that rips apart in flight. Generally, what we see is that the software was coded correctly based on the requirements provided to the people coding the software but the problem lies in the requirements and specifications provided to them. If a certain scenario was not considered in the requirements it is unlikely to find its way into the final computer coding. The AD describes an emergency scenario where a sensor reads an erroneously high AOA and the software reacts as its designers intended. The software responds to the erroneous indication in a manner similar to the way a human might react. However, all the pilot sees is the final result. How the computer came to take an action is opaque. This makes it very difficult to crosscheck the computer's process model (decision making process). As Boeing and the FAA AD explain, the bad AOA sensor leads to several problems. The erroneously high indication of AOA first leads to an autopilot disconnect. The system then works to prevent a stall by adding nose-down trim. So how does this affect the process model (mental model) for the pilots? As Boeing and the FAA AD explain, the bad AOA sensor leads to several problems. The erroneously high indication of AOA first leads to an autopilot disconnect. The system then works to prevent a stall by adding nose-down trim. It is standard in the Boeing aircraft that the stabilizer trim can be stopped by moving the control column in the opposite direction. Aircraft designers assume that no pilot would intentionally trim the aircraft nose up while also pushing forward on the controls to pitch the aircraft down or vice versa. However, in the case of the B-737 MAX 8 and 9 there are reports that reversing the control column (pulling back) won't work to stop the stabilizer trim from trimming nose-down in the scenario described in the AD. Others have discussed the rationale behind this design decision[5], but suffice to say that this would be different than what a pilot would be expecting based on previous experience on other Boeing 737 models. The erroneous AOA could trigger both an erroneous stall warning and a pitch down (due to the MCAS trimming the horizontal stabilizer). This gets a lot more complicated when you consider how the FAA defines a stall condition for a transport category airplane (adapted from Title 14 CFR 25.201): Full stall condition - any one, or combination, of the following: - A nose-down pitch that cannot be readily arrested, which may be accompanied by an uncommanded rolling motion - Buffeting of a magnitude and severity that is a strong and effective deterrent to further increase in angle of attack - The pitch control reaches the aft stop for 2 sec and no further increase in pitch attitude occurs when the control is held full aft, which can lead to an excessive descent rate - Activation of a stall identification device (e.g., stick pusher) As can be seen, the condition described in the AD would present at least two of the criteria. First is the "nose-down pitch that cannot be readily arrested" (because the pilots were not previously aware that the system was intentionally doing that due to the erroneous sensor) and second is the "activation of a stall identification device," in this case, a stick shaker, also due to the same erroneous sensor. The pilot could effectively be misled as to what is actually going on by the software system. The AD also implies that it is possible that the trim cutout switches (guarded switches that disconnect electrical power from the trim system) may not work, stating: "If relaxing the column causes the trim to move, set stabilizer trim switches to CUTOUT. If runaway continues, hold the stabilizer trim wheel against rotation and trim the airplane manually." Pilots are often our own worst enemy, with some contending that the situation should have been obvious, the aircraft attitude was nominal and airspeed normal. Such Monday morning quarterbacking suggests hindsight bias. The pilot placed in the middle of this situation does not have the benefit of knowing the outcome. They see the aircraft pitching down and are getting a stall warning. There has been considerable emphasis on stall recovery in the wake of the Air France 447 accident. In the aftermath of that training, pilots are being trained that a stall in a transport airplane is not always apparent nor do all stalls provide the kind of cues pilots might expect based on previous experience. Simulators are not able to fully replicate a real stall in a transport airplane, hence the training emphasizes respecting the stall warning system. Of course this creates a new quandary. Consider a crew who incorrectly believes they are in a stall situation analogous to the Air France 447 accident, with the nose attitude at a nominal state but the actual AOA is quite high. They might try to recover by pushing over. In other words, the system is tricking the pilot into believing they might be in a non-existent deep stall. Absent any flight deck indication that the information they are relying on is wrong, it would be difficult to pass judgment on a pilot that is following their training. Perhaps we need to consider adding a flight display alert that prominently shows an AOA failure with a mismatch AOA alert. This approach would parallel similar alerts for airspeed or altitude indication failures. Accomplishing this would be fairly straight forward. Most transport airplanes have at least two, sometimes three, AOA vanes and sensor systems. A system such as outlined by Ossmann and Joos (2017) would be one possible solution: An advanced fault detection and diagnosis (FDD) system to monitor the triplex redundant angle of attack measurement of a commercial large transport aircraft has been presented. The FDD system incorporates signal- and model-based fault detection algorithms. Fault isolation is achieved by an individual monitoring of the three angle of attack sensors[6]. An alert would be valuable in any case. This is especially true when we consider what happened with other AOA failure events, such as occurred on the Airbus that led the system protection systems to make extreme maneuvers on Qantas 72. (https://en.wikipedia.org/wiki/Qantas_Flight_72). Such an alerting system would provide the pilots with the information they need to disconnect flight computers or other actions as appropriate. This should be combined with ensuring pilots understand all of the functionality of the system so they would recognize all a particular sensor failure might impact. Every flight depends on pilots to "fix" problems that designers did not anticipate, be they in aircraft design, procedures or the entire system design. Give the pilot the information and skills to do that. Give the pilot information that the system has an erroneous input via its sensing system. How can we prevent future problem like this? A systems approach to analysis would be a good start. Identifying the needs up front prior to writing the requirements for the software has to happen. Implementing System Theoretic Accident Models and Processes (STAMP) would likely be the best solution we have at present. The majority of current risk analysis methods (FTA, Bow-Tie, FMEA, FMECA, PRA,, HFACS, ARP 4761, MIL-STD-882 etc.) are just not up to the task for finding complex system interaction problems as has been described here. Nor are those methods well suited to identify problems in systems that rely on humans and software. STAMP (see http://psas.scripts.mit.edu/home/) can provide a way forward. Knowledge can keep you alive. Captain Shem Malmquist is a veteran 777 captain and accident investigator. He is coauthor of Angle of Attack: Air France 447 and The Future of Aviation Safety and teaches an online high altitude flying course with Beyond Risk Management and Flight Safety Information. He can be reached at shem.malmquist@gmail.com Copyright © Shem Malmquist 2018.
  12. It is simply more political/bureaucratic empire building. It is what they do.
  13. This guy wasn't going to take being told that he was too late as a final answer... https://www.bbc.com/news/world-europe-45663321
  14. The only possible reason I can see for taking this plan is if you can find better health coverage elsewhere and I doubt that you can.