Jump to content

MEC

Atømican
  • Content Count

    74
  • Joined

  • Last visited

Community Reputation

3 Serf

About MEC

  • Rank
    Apprentice
  1. MEC

    Problems with the 737MAX ?

    Re pickle forks, they are airframe fittings which distribute major loads around and along the fuselage, and also also incorporate failsafe functionality where the fuselage meets the wheel well, wing aft spar, landing gear load point. If you find cracks "repair before further flight". Boeing say you cannot fly the aircraft until the issue is resolved... and I've heard the fix is presently about 1800 man hours over 11 days using an expert Boeing team. Intensive! Boeing are working on a better solution. AD: http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/b7003a93c909869e8625848800467eb9/$FILE/2019-20-02.pdf From the AD: "Do a detailed inspection for cracking of the left and right hand side outboard chords of the STA 663.75 frame fittings and failsafe straps adjacent to the stringer S-18A straps, in accordance with Boeing MultiOperator Message MOM-MOM-19-0536-01B, dated September 30, 2019. If any crack is found, repair before further flight using a method approved in accordance with the procedures specified in paragraph (k) of this AD. Repeat the inspection thereafter at intervals not to exceed 3,500 flight cycles" (which is roughly every 2 years).
  2. MEC

    Roll Call!

    It's hard to stay away. This is a cool corner of the net. Do you remember Virtuoso from the old days? That dude was smarter than 10 of me!
  3. MEC

    how crap is this government ?

    Hey Leonid, I've really enjoyed reading your posts & your perspective over the years. Reading the last few posts you've made I am wondering if it is possible to have any positive take on socialism after living through the collapse of the Soviet Union.
  4. MEC

    Problems with the 737MAX ?

    Great posts! Love the history. MD might have infected the bean counters at Boeing, but when aviation companies were falling over in the 70s Boeing were the beneficiaries gaining new design engineers from across the industry. Culmination; the amazing 767. Everything Boeing have done with commercial airliners since basically follows 767 suit. The 747 is frequently considered to be a conversion of Boeings failed pitch at the previous airforce heavy lift freighter competition, but Joe Sutter says in the book 747 (https://www.amazon.com/747-Creating-Worlds-Adventures-Aviation/dp/0060882425) that it was a completely fresh design. There were engineers who came from the freighter design group to help design the wing, but Sutter binned their work! The Pratt & Whittney engines are probably the closest thing from the freighter program to make it onto the 747. And while the 747 was designed in the back office, Boeings 'best' engineers were spending the big bucks in the SST room. I guess the B-1 probably came out of some of that work. Damn shame that UK aviation imploded. They had an amazing ability to think outside the square & some very funky designs. I love UK aviation museums! And I did get to see a loud & spectacular Tornado flying at the 1988 Australian International Airshow which came in fast & low then pulled straight up in a blaze of afterburners until it disappeared into space!
  5. MEC

    Problems with the 737MAX ?

    Heya Chrisg, great to see you here! 787 is a pretty amazing machine with so many tech advances. ANA have suggested it is 22% more efficient than the FADEC 767. Composite structure is solid but because it's so solid impact damage can be hard to detect unless it is noticed & reported & then ultrasonically inspected. And erosion can be an issue around the window cutouts, service doors, fuselage section butt joints, etc which are protected by titanium foil. Will be interesting to watch them age. The trailing edge devices all trim the wing in various phases of flight for wing load alleviation or cruise balancing with no indication on the flight deck. The main computers each pull 200 amps on startup. Their are several independent networks hosting a ton of different network standards from Boeing proprietry to ARINC, IEEE, TCP/IP, CANBUS even. The windows are big. The tears of departing loved ones are collected and injected into the electric aircon packs to humidify the cabin! It's quite a machine. I hope Boeing's next new aircraft designs are well ahead of the competition as a result of 787 tech, but the MAX is certainly making me wonder if Boeing has lost it's way a little. MCAS is so far below par regarding well learned & established system redundancy in modern aviation. One sensor ops in a newly introduced, automated, hidden system is aviation sacrilege! Unbelieveable! My basic understanding of MCAS is that it is intended to make the very powerful MAX feel & fly like an NG. Due to engine position & power, I've been told that at high thrust settings the MAX wants to nose up significantly. With LEAP engines the basic 1960s airframe is a literal hotrod! MCAS smells 787 software fix to me, & the 787 is all about making the machine feel like it flys like an aircraft should. But such a quick (arrogant? ignorant?) fix on the MAX is disappointing, especially considering there is another AOA sensor, inertial data & Earth reference data available. Still can't help wondering why the Lion Air crew, & especially Ethiopian pilots didn't cutout the stab. Another hole in the swiss cheese. Makes you appreciate good pilots & good training, & ponder too much reliance on automation & complacency in modern aviation cockpits. 737 has been a great aircraft over the years but they probably should have stopped at the NG. And on canards, I would have loved to see Boeing build the Sonic Cruiser.
  6. MEC

    Roll Call!

    Been MEC since I signed on when the old atomicmpc site was alive. I think it was archived? Not sure if it's still around. I was often lurking around Chrisg's aviation posts, but loved the Green Room groove & political discussions. Haven't really been too active in the new world. Keep having kids and they've all inherited ADHD! Keeps us busy.
  7. MEC

    Problems with the 737MAX ?

    Hey all, been a while since my last visit here. Chrisg, g'day! Your posts are fantastic. There is more information here than on pprune! I reckon the 787 development hurt Boeing so much that they've been unable to advance beyond the 737 with confidence, and the progression to the MAX is evidently compromised. There is little other competition in that market & Airbus, who were brought to their knees developing the A380, have also been able to get away with upgrading their A320. Duopoly? Any competition seems to be a way behind... except maybe for the A220 which is a pretty amazing machine but just too small to challenge in the 737/320 arena. 737MAX delays are really hurting. I wonder how many airlines waiting for the MAX are still operating older aircraft which were meant to retire, carrying their end of life defects as long as they can, but now needing to last & last & just keep on flying. The 737NG pickle fork issue is going to hurt a bit, especially for airlines waiting on the MAX as a replacement. In Qantas case they have only inspected aircraft with more than 22,600 cycles as per the Airworthiness Directive. That accounts for 33 of 75 737NG aircraft. Qantas highest cycle 738NG is almost 18 years old & has approx 28,000 cycles. I believe Virgin have almost completed inspections on all their aircraft, including those <22,600 cycles. It is interesting that some airlines have found cracks in aircraft with <22,600 cycles! I also wonder how much Boeing have enjoyed US govt rocket launch contracts over the years, & if the success of SpaceX is hurting them.
  8. MEC

    Roll Call!

    Hi! Been several moons since my last fly by. I don't have a lot to say but I've loved reading the ponderings and postings here over the years. You folks is smart! Guess I signed on some time around 2002, give or take?
  9. MEC

    Dumping Fuel ...please explain.

    Your post has already generated good discussion so I wasn't going to add more when it's already been addressed, but here's my 2 cents. Much has already been suggested about what quantity of fuel might make it to ground or sea, but there are a few good stories from people who have experienced a fuel dump incident here: http://www.airliners.net/aviation-forums/g...d.main/4102030/ One post that I found interesting was this: "And ironically, dumping fuel actually saves fuel. If the structure of all commercial heavy aircraft would have to be designed to sustain landings at MTOW, we would carry a lot more structural weight in every aircraft, and hence burn more fuel. " One fuel dump I recall involved an extremely lucky Emirates A340 which dragged it's arse halfway down the main runway at MEL before taking out most of the antennas and barely clearing the fence! Very near miss & barely reported. Computers had been provided incorrect weight figures by a fatigued F/O & doubled checked incorrectly by an even more fatigued captain! This struggling aircraft dumped fuel over Port Philip Bay at midnight. Regarding using fuel more constructively I'd first like to highlight that although the landing gear is capable of absorbing landing loads at Max Takeoff Weight, the structure of the aircraft is likely to sustain damage. Also, any aircraft suffering from a heavy landing requires significant maintenance inspection, so the aircraft will be out of service for several hours for inspection & whatever other time it takes to repair any damage found. With this in mind, and considering the damage already incurred from the suspected tyre failures (at the time of take off), it makes good sense to return to a base where there are resources such as personnel, equipment & logistics to return the aircraft to service ASAP. Travelling on toward it's destination with the landing gear extended increases drag & limits the aircraft to low speed & low altitude, increasing fuel burn & reducing range significantly. As an example, that Emirates A340 flew clean, gear retracted, but unpressurised from Melbourne to Toulouse for final & extensive repair. Rather than making the trip in 2 legs it took 11! That is a pretty good example of an advantage of high altitude flight. The delays across Australian aviation networks were due to the debris cleanup & runway inspections. Also the fact that airlines don't have much room to move with aircraft running tight schedules, quick turnarounds & usually no spare aircraft. There is no fat left in the airline business anymore. The cheapest airfares cut deep into service & product quality, and there is little elegance left in flying today. Perhaps economics contributed to United's 744 tyre failures. Then again, it's just as likely to have run over FOD that came off another struggling operators aircraft!
  10. MEC

    Dumping Fuel ...please explain.

    Hi chrisg, haven't been around much for a while. I'm captivated by my children. We had our fourth child in Feb so plenty of little MECs pulling stuff apart & running amok! Still try and check in every couple of months or have a read when something significant happens out in the world. It's nice to see what all you smart people are thinking & conversing about. I'd love to add more to the discussion but I think it's all been taken care of! There is a lot of knowledge, experience and simple good reasoning in here. :)
  11. MEC

    Dumping Fuel ...please explain.

    Listening to the archives of ATC, UA840 calls the tower to notify of blown tyre on takeoff. This shutdown the main runway for about 30 mins and caused total chaos & flt delays right across the country for much of the afternoon. ATC archives are here: http://www.liveatc.net/archive.php For the takeoff archive select UTC date 20Oct2013, feed YSSY Tower/App, UTC time 0400-0430Z. ~7.50 UA840 calls the tower reporting apparent blown tyre and is so calm. It always impresses me how professional pilots manage to stay so calm. For landing archive select UTC date 20Oct2013, feed YSSY Tower/App, UTC time 05300-0600Z. ~1330 UA840 reports 4 miles out on approach for landing. Pilot & ATC cool as cucumber regardless of impending doom! Oh, that's right, it's not a 380... they're safe aboard a Boeing 744! :) ~1540 UA840 asks tower what damage they see to aircraft.
  12. MEC

    Dumping Fuel ...please explain.

    Eveln, I nearly spat a mouthful of tea over my keyboard laughing at your response. But I'm pretty sure this is the kind of maneuver that keeps long haul pilots from getting bored! I'm not sure how Air Traffic Control allocate airspace for these kinds of incidents. I imagine that Chrisg & Rybags talk on Standard Operating Procedures and Standard Practices are on the money. Every fuel dump I have heard out of SYD has been out east & over the water. I know there are altitude recommendations for dumping fuel where higher altitude gives the fuel more opportunity to disperse and evaporate. On flightradar24.com the aircraft remains at ~10,000ft and over the water for much of the fuel dump. SYD-LAX is one of the longest flt legs a non ER 744 operates and fuel tanks are normally full with ~180,000kg(~225,000litres). A 744 at max takeoff weight is ~400,000kg but max landing weight is only 295,000kg. So I expect it will have dumped ~100,000kg(~125,000litres) of fuel prior to landing. That's a pretty expensive fuel dump! Also noted from flightradar24.com was an airspeed which stayed around 300kts which is a pretty good indication that they left the gear extended the whole time. There are no cameras on 744s to determine the extent of damage so it would be dangerous to retract damaged landing gear and risk further damage. Worth a mention after the safe outcome, an interesting feature of the Boeing 747s is that they have two sets of main landing gear, body landing gear & wing landing gear, each of which is independently entirely capable of supporting the aircraft during landing at max landing weight. There is so much redundancy in the 747. What a wonderful, safe machine!
  13. MEC

    Amazing Quadcopter Demonstration

    Wow! That's impressive automation. The agility and speed are impressive. Good to see that it missed one of the balls thrown toward it. When these little terminators are hunting us it's nice to know they are not perfect! :P
  14. MEC

    Dumping Fuel ...please explain.

    From http://www.smh.com.au/travel/travel-incide...1020-2vuwo.html And here is the flight track for the dump and return. http://www.flightradar24.com/2013-10-20/04:30/12x/UAL840
  15. MEC

    Polls, are open, vote, vote, vote!

    Who would determine the proportions? How would you group people? I agree that plain old democracy doesn't work the best (you need a well educated population for that), but what alternative do we have? I think there are many alternatives but the best systems in practice so far seem to be in the form of representative democracy. As such I feel we should allow each individual to be represented by their choice of rep. I don't think it is particularly significant in the Australian Federal system to vote for somebody in a nearby geographic area. I'd rather have my vote represent a voice I support regardless of geography. With the current electorate & preference system I expect that more than 45% of Australians nationwide are not represented by their first voting choice, but possibly much higher. Non electorate, proportionally allocated seats in the houses of parliament might offer greater representation for the population in a political system that is otherwise the same... for the time being. Small steps? Surely we have the tech now to allow this voting system & enhance our 'democracy'? And I agree entirely on the benefits of education. Not sure what you mean. Do you mean we should have multiple candidates elected for each electoral division in the House of Representatives? The multiple candidates concept is certainly an alternative and worthy of consideration, but I think the easiest small step forward could be achieved by utilising proportional representation nation wide with no electorates. From wikipedia proportional representation is a system whereby "the number of seats won by a party or group of candidates is proportionate to the number of votes received". http://en.wikipedia.org/wiki/Proportional_representation
×