Don Hudson

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  1. TWO great-grandbabies?! How wonderful for you, Greg! Please say hello to your son & family for us. We have 3 GB's, 4, 2 & 4mo...we're often a hundred-and-an-eighth in coloring books, toys & 95-110db these days - ! Yes, the Neo...never understood the switch to a 1966 cable-&-pulley bread-and-butter type. I hope it works out for Boeing, and all the airlines that trusted and bought the airplane, but truly, it's an organizational & design/engineering lesson that never should have needed learning.
  2. Hi Greg; The splash-screen seen here in the link to the video posted by Jaydee is a clear illustration of the change in the engine/cowling arrangement, (a "btw", IEEE is a technical/profession/engineering association of which the gentleman who wrote the article is a member.) From the article: The last statement about the raised thrust line being the cause of the pitch up does not make sense. A thrust line that is closer to the longitudinal centerline of the fuselage does not increase force, it reduces it, so the statement is wrong right away without examining the actual design. The higher thrust line is not the reason MCAS was required. It is stated that the increased area of the engine cowlings providing an increase in lift at higher AoA's. This lift came just at the point where the older Boeings would be providing a heavier control column feel to the pilots, which certification standards, (CFR 25.173, I have seen quoted, pasted below), required. On the MAX, as speed reduced and the stall AoA was approached, a certain, required "pull" on the control column was not evident, so Boeing used the MCAS solution to provide this additional pull, which was necessary if the single B737 "type" was to be retained. They just don't appear to have done an "FMEA" when designing/building the system. MCAS action is intermittent, and if the trim wheels are seen rotating right after takeoff, it's the same as STS, (Speed Trim System) operation which is designed to force the pilot to trim out the artificial-feel forces as speed increases. Since the late 60's, we've been trained to recognize a runaway stabilizer as a continuous event, not an intermitent one with "intervals" of operation, which do not raise awareness, signal danger or provide a hint of what's actually happening, particularly when the crew is trying to determine why the stick shaker is activated and the airspeeds appear unreliable. Cheers as always, Greg!
  3. blues, re, "Interesting scrape marks.", yes, and also on the corner of the aileron, perhaps while it was full-down?...(brrrrrr). I have had the experience, once, of "running out of aileron" in a cross-wind in YYC, (A320) while the airplane kept rolling. It would be at the point where the airplane was likely in Direct Law, and I suspect this A321 was in the process of entering Normal Law...I'd have to get out the books. Oh,...wait,...
  4. It's not possible to know/predict the chances of that happening, but the drill is to hold the trim wheel & re-trim to neutral and continue to trim using the manual trim wheels as required.
  5. Both AoA sensors are used by the FCCs on alternate flight legs. The switch between left & right is accomplished through WoW sensing. One hopes the change includes some resiliency in a brittle system that breaks quickly and badly and instead fails gracefully, permitting crews time to assess what kind of runaway they're dealing with - continuous, or by 5" intervals which mimicks STS behaviour after lift-off. Along with comparison software that stops just the MCAS with an AoA disagreement of say, > 5°, one hopes there is clarity for crews on what the cut-off switches actually do. I believe they're both shut off now in the Runaway drill?
  6. j.k., agree with your comments. Also, at time 2:56, the video misleads viewers on the fundamental reason for the existence of MCAS on the MAX. Quote: "Except, moving the engines up on the 737 had a side effect. When the 737 was at full thrust, like during takeoff, the nose tended to point too far upward which can lead to a stall. This was a problem because these planes were supposed to behave like the old ones." end quote. They show the reason for the engine arrangement on the MAX quite well, but the statement regarding thrust & stalling at takeoff defies physics - moving the thrust line higher and thus closer to the longitudinal center of the fuselage, (or just above the floor-line) reduces, not increases, the effect of thrust line. The reason for MCAS is, the increased cowling area for the LEAP engine produced sufficient lift so as to render too-light a response when the a/c was nearing entry to the stall, (discovered in early flight tests). The reduced 'feel' of the CC did not conform to design standards under which the type was certified (in 1966). To be certifiable under the same type, it had to be demonstrated that the MAX had the same response as all previous B737s. Keeping same type was crucial to the sale of the aircraft. MCAS, which produced the required "heavier" control feel was Boeing's solution. This is all simplified I know. The false statement in the video invites an incorrect conclusion regarding the stall warning/stick shaker at takeoff on both accident aircraft, which occur for entirely different reasons to do with the left AoA sensor and possibly the left FCC.
  7. There is lots of scaffolding, meaning renovations were taking place. https://www.msn.com/en-gb/news/other/notre-dame-cathedral-statues-flown-away-for-renovation/vi-BBVRov0
  8. https://www.theguardian.com/us-news/video/2019/apr/14/worlds-largest-aircraft-takes-off-and-successfully-lands-video A manned giant six-engine aircraft with the world’s longest wingspan – surpassing Howard Hughes’s infamous Spruce Goose – took off from California on its first flight on Saturday. The twin-fuselage Stratolaunch jet lifted off from Mojave air and space port and climbed into the desert sky 70 miles north of Los Angeles. It successfully landed two hours later. The aircraft is designed to carry as many as three satellite-laden rockets under the centre of its enormous wing, which stretches 385ft, or 117 metres.
  9. Okay, there it is, confirmed, many thanks thinair.
  10. Seattle Times With close industry ties, FAA safety chief pushed more delegation of oversight to Boeing April 14, 2019 at 6:00 am By Dominic Gates Seattle Times aerospace reporter In 2012 the Department of Transportation’s Inspector General sent investigators to interview Federal Aviation Administration (FAA) technical staff in Renton, where engineers working under manager Ali Bahrami were responsible for certifying new planes developed by Boeing. The investigation substantiated employee allegations that FAA managers did not always support efforts by their technical experts to ensure Boeing complied with safety rules. It found “a negative work environment” where safety engineers feared retaliation “for attempting to hold Boeing accountable.” Now, two fatal crashes of Boeing’s 737 MAX have brought new scrutiny to the close-knit relations between the regulatory agency and the industry, to the FAA’s practice of delegating most safety analysis for new Boeing airliners to Boeing itself, and to shortfalls in the FAA’s final oversight role. With the MAX crisis jolting public faith in both Boeing and the FAA, Bahrami, now the executive at FAA headquarters in Washington D.C. specifically tasked with ensuring aviation safety, faces the daunting task of restoring confidence in his agency and in the process of certifying aircraft as safe. Hank Krakowski, former chief operating officer at the FAA, says, “Ali, coming from the certification branch in Seattle, is uniquely qualified to manage through this current situation.” But Michael Collins, a just-retired aerospace safety engineer who worked under Bahrami here, sees him as representing what’s gone wrong at the FAA. “He helped foster a culture among management in Seattle of delegating more than the FAA technical specialists were comfortable with,” said Collins. “When the FAA’s safety engineers had an opinion different from Boeing’s, he tended to side with Boeing.” Personifying tight FAA/industry relations Bahrami, 64, was born in Iran and came to the U.S for his education not long before Ayatollah Khomeini’s 1979 revolution. That year, having already earned a B.S. degree in engineering, he completed his M.S. at the University of Michigan and like many educated Iranian exiles decided not to return to his newly theocratic homeland. Instead, he took a job as an engineer with Douglas Aircraft in southern California, where he spent 10 years. Bahrami joined the FAA as an engineer in 1989, then rose to become in 2004 manager of the Transport Airplane Directorate in Renton, which oversees the safety of the operating fleet of U.S. commercial aircraft as well as the certification of new airplane models. During his tenure in Renton, Bahrami spearheaded efforts to delegate more inspection and certification work to industry, and specifically to outsource much of the safety analysis of new Boeing jets to Boeing itself. In 2013, Bahrami made a move reflecting the tightly intertwined relationship between regulator and industry. Just months after overheated batteries in flight caused the worldwide grounding of Boeing’s recently introduced 787 Dreamliner — a jet that Bahrami had shepherded through certification — he left the FAA for a lucrative lobbying job as a vice president of the Aerospace Industries Association,representing the big U.S. aerospace companies. That fall, testifying for the trade group before the House Subcommittee on Aviation, he painted the regulatory process as too slow and asked for changes to make it “more responsive to industry.” “We urge the FAA to allow maximum use of delegation,” Bahrami told Congress, now wearing an industry hat. “It would be detrimental to our competitiveness if foreign manufacturers are able to move improved products into the marketplace more quickly.” Then in 2017, he returned to the FAA executive ranks at just one level below the top job: Based at FAA headquarters, he’s now associate administrator for aviation safety, overseeing 7,200 employees and a budget of $1.3 billion. Former National Transportation Safety Board (NTSB) chairman Jim Hall succinctly summed up his view of Bahrami: “He’s been the agent for Boeing’s self-certification.” Bahrami, in emailed responses to questions, defended the delegation of safety analyses to Boeing and other private companies, and disputed Hall’s characterization. “Delegation is not self certification,” he said. “Our staff remains engaged throughout the certification process.” The U.S. aviation system, he insisted, “has never been safer.” Boeing controls certification Today’s reality is that when Boeing designs a new airplane, almost all the hands-on safety evaluations and tests are done by employees of Boeing or Boeing’s suppliers who are authorized to represent the FAA. These Authorized Representatives (ARs) file written documents that are then evaluated for compliance and signed off by FAA technical specialists. A Seattle Times investigation published last month showed that the safety analysis of a new flight control system on the 737 MAX that played a major role in the fatal crashes of a Lion Air jet last October and an Ethiopian Airlines jet last month was done entirely by Boeing. In addition, FAA engineers complained of being asked to delegate even more of the work to Boeing than originally agreed and of a constant schedule pressure during MAX certification. They said they were often given insufficient time to finish the evaluations — which in that case were sometimes signed off not by the technical staff but by managers or even just delegated back to Boeing for a final decision. In the case of the MAX’s suspect flight control system — called Maneuvering Characteristics Augmentation System, or MCAS — as a result of flight testing in the final year of certification, Boeing made significant changes to how it worked, including in certain circumstances increasing by a factor of four the system’s authority to move the horizontal tail so as to push down the nose of the plane. Those changes were never communicated back to the FAA technical staff, who had seen only a system safety analysis prepared before the changes. Drawing on Boeing’s expertise As the 2012 Inspector General (IG) investigation indicates, there was constant tension throughout Bahrami’s tenure as FAA boss in Renton between the agency’s technical staff, who wanted stringent application of the safety regulations, and managers who pressed for more speed and ever more delegation to Boeing. Mike McRae, a former senior aerospace engineer at the local FAA office, retired in 2013, a month before Bahrami left for his four-year stint working for industry. McRae said he retired unhappy with the direction of the safety agency and management’s lack of support for technical staff. He described Bahrami as a very capable bureaucrat who merely implemented the policy of increased delegation that was pushed from FAA headquarters. When Bahrami came in as boss, the policy was already firmly in place, mandated by Congress under heavy lobbying from Boeing and other giant aerospace companies. “He was a product of that culture,” said McRae. “He was inclined to delegate more. He thought we had to get the companies to take more responsibility for safety.” “That’s not irrational,” he said. “Delegation is an unfortunate necessity. You can’t fund an old-school regulatory FAA.” But McRae added, “I personally think they took it too far.” Bahrami himself argued, both from inside the FAA and when he spoke for industry, that there’s no alternative to delegation. The FAA has only about 1,300 personnel in its certification offices around the country, compared to the 56,000 engineers at Boeing. At a 2013 NTSB hearing after the 787 was grounded due to overheating lithium-ion batteries, Bahrami testified that he had only 20 to 25 staff working on the jet’s certification, so the FAA had to rely on 950 Boeing ARs to oversee and approve the detailed work. FAA personnel who certified the 787 never visited the battery manufacturer in Japan nor the company in France that designed the surrounding battery system. Boeing ARs handled all of that. And two IG audits have turned up shortcomings in the broader delegation process. An audit in 2011 found 45 instances between 2005 and 2008 where the agency had not carefully reviewed certification plans in advance, including one plan that didn’t comply with the regulations governing aircraft flight controls. A 2015 audit revealed that the previous year the agency had performed direct oversight of only 4 percent of the ARs conducting certification work on behalf of the FAA at aerospace suppliers. Bahrami co-chaired an extensive review of the airplane certification process in 2012. Tellingly, he was the only FAA representative on the review committee along with eight representatives of industry. The co-chair was Christine Thompson, a senior manager of Boeing’s airplane certification organization. That review recommended that because “the FAA has limited capacity,” it should “maximize delegation to the greatest extent.” A year later, now testifying for the industry, Bahrami told the House committee that due to lack of resources and budget the FAA simply cannot perform all the technical audits required to certify planes as safe. “Expecting FAA to keep pace with industry … is not in the realm of possibilities,” he said. Answering questions this month via email Bahrami said that this delegation of work to industry “enables regulators to leverage expertise at manufacturers’ facilities.” He added that the shortage of engineers throughout the aviation industry means the public sector must compete with the private sector in attracting talent. “Given the complex nature of today’s aviation products, it is virtually impossible for regulators to have all necessary expertise in every FAA office throughout the country, especially when global manufacturing models continue to evolve and grow,” Bahrami wrote. Mo Yahyavi, a former top executive at Boeing who ran the 747-8 program while that big jet was being certified in 2010, said Bahrami came with his team and toured the Everett production line as the test planes were being built, to verify and validate Boeing’s work on the design and testing. “I really was impressed with the guy as a hands-on person and trustful,” said Yahyavi. Earlier in his career, Yahyavi was himself designated an FAA representative at Boeing specializing in propulsion systems, and was given extra training for that role in how to interpret and define how the jet’s software worked with its mechanical systems. He said ARs at Boeing all have such specialized expertise. “There’s no way a certification organization like the FAA can understand and verify and validate everything by itself. They depend on the manufacturer’s engineers.” “The system was working,” Yahyavi concluded. “I wouldn’t change anything.” The gold standard of air safety Until the MAX crashes, regulation of aviation safety in the U.S., where 2.6 million passengers fly every day, has been the model for every other country. The last commercial passenger airplane lost in a crash in U.S. airspace was 10 years ago. In the decade since, airlines have flown 7.4 billion passengers safely to their destinations on 90 million U.S.-regulated flights with exactly one passenger death: on a Southwest Airlines 737 last year when an engine disintegration in flight blew out a window. That’s a remarkable record, not even closely approached by any other form of transportation. Former NTSB chair Hall believes the historically high level of air safety is based on years of experience and care, that’s now at risk from excessive delegation to industry. He points to the Volkswagen emissions scandal as evidence that “greed drives industry to do things that do not benefit society.” And he’s not impressed by Bahrami’s argument that the FAA doesn’t have the resources. “I have a hard time understanding anyone who sells increased industry participation by essentially saying that the agency he represents is incapable of doing its job,” said Hall. “Safety depends on checks and balances,” he added. “When you don’t have the checks in place, things get out of balance.” In the wake of the two MAX crashes, Congress has been scrambling to hold hearings and demand accountability. The House Committee on Transportation and Infrastructure has requested records from Boeing and the FAA as part of its investigation into the 737 MAX certification process. And yet Congress itself has backed that process, with prodding from the industry. The latest legislation, the FAA Reauthorization Act of 2018, passed into law just weeks before the Lion Air crash last October, requires the FAA to “delegate fully” unless the head of the agency determines there is specific public safety reason to limit the delegation. In such a case, the FAA is instructed to work with the industry partner to return it to full authority. Furthermore, if any certification glitch occurs to slow down an airplane program, the FAA must automatically elevate the issue to management and resolve it within a time period agreed with the manufacturer. Hall says the reason for such provisions is straightforward: The heavy lobbying of Congress by Boeing and other aerospace companies. U.S. Transportation Secretary Elaine Chao, the ultimate boss of the FAA, is the wife of Republican Senate Majority Leader Mitch McConnell. But the influence is bipartisan. In the late 1990s, the deputy FAA administrator and for a time acting administrator was Linda Hall Daschle, wife of U.S. Senator Tom Daschle, then Democratic Senate Minority Leader. Linda Daschle left the FAA to work as an aerospace lobbyist. Former FAA chief operating officer Krakowski defends the role of manufacturers in ensuring the safety of their own products. While there is always commercial pressure to meet schedules, he said, jet manufacturers face a more existential pressure to make their airplanes safe. “If you don’t, the ramifications for Boeing and the airlines are evident right now” with the MAX crisis, he said. “I think there is a moral driver (to protect passengers) that Boeing does understand, but also, from a business point of view, the consequences they are living with right now are an additional driver.” Yet somehow, this complex safety ecosystem failed on the MAX. Krakowski said that the missed flaws in the MCAS flight control system that seem to have caused both recent crashes mean something went wrong not only at Boeing and the FAA, but also at the major airlines, where the flight technical departments “typically know every nut and bolt on the airplane and how it should operate.” “All three own a piece of this. Nobody raised a hand and said, wait a minute, let’s talk more about this system,” he said. “I’m thunderstruck nobody caught this.”
  11. Gosh, I don't know what's acceptable anymore conehead. We are in a period of great flux. As my brother, an electrical engineer, says with a smile, "That's the wonderful thing about standards: there are so many to choose from." To me anyway, the Boeing manuals I have experience with are thin on information. The details of what a control or indicator actually does and how it works are absent. I think there is less than even pilot-NTK information but that's just my view. I know the reasons, one of which Boeing itself stated recently with regard to MCAS. So, for the 250 turns, I have two sources...one was a PPRuNe post on the Ethiopian thread, and the other was a site where someone was building their own flight-simulator and made the statement regarding "250 turns". Kip's mental filing cabinet may very well be functioning perfectly! One way or another, people will find things out, fill stuff in or, these days it seems to me, with increasing legitimacy, just make up the information they want or need. It's always best that original, formal sources, (the manufacturers, the regulator, etc.), share as much as they can when working in high-risk enterprises. Otherwise, trust in information, (and resulting behaviours) become an issue as we "choose" our standard then claim we've met it. Not a good way to do aviation, in my opinion.
  12. Yes, I think that's a reasonable notion. On turns of the wheel, I've read that it takes 250 turns to go from full NU to full ND, (17°), or 14.7 turns for one degree or 0.068° per turn. That is not verified in any manual to which I have access, but if it's that, one can understanding giving the method up and turning the system back on again. If it's 40-45 turns for 17°, then its just over a third-of-a-degree per turn. I suspect the mechanical advantage, (ratio of 1 turn to how much the stab moves) would be small and the wheel would be very difficult to move. As shown in the traces with the last two blips of trim, the Pitch Trim parameter moves so the CC trim switches worked, which I believe is evidence that the manual method would have worked but not fast and probably not easily. - they had a long way to wind the trim ANU at ~15 turns per degree. I don't know how units and degrees relate - and I could be using "degrees" when it might be "units". Again, there is no information in the AMM, the AOM or the FCTM.
  13. Hi Kip; Yep, got that, thanks. As I expressed in my previous post to Turbofan, “Main electric” would of course be the control column switches." But that illustrates why I wrote the full descriptions in red font in the original post of the article from AW&ST - the article uses the term "manual" when referring to the trim wheels but conflates the term "manual" when applied to the trim switches on the control column because they're manipulated by hand even as they are controlling an electrically-driven, (primary) trim system. edited to add: There is further confusion regarding manual & electric trim - it is claimed, (but without verifiable evidence yet) that the manual trim wheels could not be moved. One theory is, "HS stall due high loads on the trim mechanism due high airspeed". But the trim moved ANU when the crew used the CC trim switches, (indicating, along with MCAS input, that the cut-off switches had been moved back to their normal position). Manual trim using the wheels doesn't work but electric does? Why? On Woody's comment, yes, got that too but probably didn't express it very well. It makes complete/logical sense that if the trim has run away due MCAS and nothing was done until time had passed, then when the trim is cut off by the CUTOFF switches, it freezes the system with whatever trim was in prior to using the switches. That's why the NNC states to trim neutral then cut-off the trim, (but, and Woody makes this point), the FAA AD doesn't emphasize the highly-critical importance of trimming the pitch to neutral right away and then cutting off the trim system. That's the key of course, and I agree with Woody that the wording is weak and buried, but it isn't confusing - it's just obscured in all the blather of the FAA's original and subsequent ADs. This goes back to the absence of any information and therefore training for a system that controls the most powerful flight control on the aircraft which has the potential for loss of the aircraft under certain, previously-latent conditions.
  14. Hi Woody; Minor point, the Boeing FCOM wording is from the FAA Emergency AD's issued November 07, 2018 and December 21, 2018 as a revision to the AFM, (Airplane Flight Manual). It is obviously impossible to trim if the cut-off switches have been moved to CUT-OFF without trimming first, but the wording in the AD is to ensure neutral trim prior to doing so*. If I understand what you meant by, " manual trimming may be impossible ", I don't think trimming to neutral using the manual trim switches on the control column would be impossible purely due to high loads on the HS. Stabilizer 'blow-back' can occur with a "ball-screw" arrangement, (vice a screw-jack) but there are two brakes on the HS mechanism that are released whenever the electric trim or the manual-wheel trim is used. I believe that electric trim was available because there is slight HS movement concurrent with the last two blips of ANU electric trim, (resetting the MCAS which dutifully re-trims AND for ~6" resulting in the final dive). * There is no statement in the AD or the FCOM requiring that the procedures (in Fig.2 & the Runaway Stabilizer NNC) set out/referenced in the FAA AD are to be executed by memory. The FAA and Boeing leave it to individual airlines and crews to decide how to handle these procedures. Runaway stabilizer NNC: FAA AD revision: *