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Post by christrott on Mar 24, 2019 17:54:26 GMT
Wasn't SAS751 also when the tactile test became a thing with the MD-80s because it was fuel-caused ice off the wing root that caused the problem?
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Post by Peter Liddell - HJG Admin on Mar 24, 2019 17:59:48 GMT
Yes that was one of the recommended changes from that investigation.
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Post by walterleo on Mar 27, 2019 20:49:18 GMT
Hi friends:
Programing and aviation seems is not a perfect marriage: The AF 447 had a programe to activate the stall warnings which were not active below around 40 kts (?) indicated for not generating false warnings while taking off or landing. The pilots of that flight on 31 th of May-1 June 2009 where at least distracted by the stall warning going off while howling back their stick and started crying while pushing. The designers did not foresee, that their AB 330 would be flown ever so slowly and not entering a spin.
Another case: The TOWS of the MD-80 family should have avoided that distracted pilots would take off without flaps and slats. In two cases (Spanair 5022 and Nortwest 255) the warning system did not intervene, up today without conclusive explanation. Other MD 80s were also in similar situations but escaped a crash thanks to superiour flying instincts of the crew, luck, lower temperatures or weight. Never less taking off without correct configuration in any airplane is a capital aeronautical sin, but the TOWS was designed to avoid dire consequences and nobody knows why it did it not in these cases.
Kind regards
Walter
Walter
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Post by aerofoto - HJG Admin on Mar 27, 2019 21:12:03 GMT
My understanding of the NORTHWEST "prang" (in particular) is that the Flap/Slat alarm had been "manually disengaged" to silence nuisance warnings .... or so I was informed.
Mark C AKL/NZ
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Post by Peter Liddell - HJG Admin on Mar 27, 2019 21:19:18 GMT
My understanding of the NORTHWEST "prang" (in particular) is that the Flap/Slat alarm had been "manually disengaged" to silence nuisance warnings .... or so I was informed. Mark C AKL/NZ On both actually Mark, just different ways... on NWA255 the breaker was pulled (an "off the books" shortcut commonly used apparently to silence nuisance warnings during long taxis), and on Spanair 5022 it was (unknowningly) disabled by maintenance because of a problem with a sensor
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Post by aerofoto - HJG Admin on Mar 27, 2019 22:11:22 GMT
I remember departing BOG one morning for MIA on an AA A300-600.
We were a full ship to MIA that morning .... and I was seated in "Zoo Class", and at a window, just behind the wing TE .... so I could clearly sight the flap positions.
As we taxied I noted the TE flaps hadn't been extended .... I dunno about the LE devices because I simply couldn't see them from where I was.
I commented in regard to my observations accordingly and to the PAX sitting next to me .... whom was a USAF officer whom returning to MIA that morning also.
It "got both our attentions" (the TE flaps definitely weren't extended) .... and more so as we entered the RWY too .... but .... we both just "SHUT-UP" .... trusting the crew would detect any discrepancy as part of their pre-T/O recall .... "if" there was ny discrepany at all.
T/O commenced .... appeared to be "perfectly normal" (as I said I couldn't see the LE's) .... and I (we both) relaxed once airborne .... writing off our technical observation/s to possibly being something in regard to BOG's high altitude (8,500 FT ASL) and where you're through 10,000 FT in no time at all after departure.
After arrival at MIA and whilst deplaning I stuck my head into the FD .... for a brief yarn, and as I normally do with approval from the CSD, and I commented in regard to what appeared to be "a ZERO FLAP" departure. The captain .... an apparently senior guy given all the scrambled eggs on his cap .... explained to me, and with pleasure, that it was "quite a normal procedure" for the A300 out of BOG (apparently the LE's are more than sufficient) .... and we actually had an extended conversation, as I was the last PAX to leave the aircraft, as we talked together all the way to MIA arrivals.
Still .... I was uneasy to begin with having sighted what I observed prior to T/O that day.
Mark C AKL/NZ
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Post by walterleo on Mar 28, 2019 5:03:48 GMT
Hi friends:
At least the final report for Spanair 5022 could not identify the reason for the not working TOWS. The manuals for the service people did not forbid the deactivation of the not working RAT probe. But the report stressed various other failures of the crew, which not present could have had avoided the accident, especially CRM, following checklists, retarding throttles at the most critical moment, a false reaction to a presumed engine failure and lack of adequate reaction to a stall at takeoff. In the case of Northwest 255 circuit breaker 40 could have been off but in case of Spanair 5022 circuit braker K-33 was off.
Kind regards
Walter
P.S.: As I have flown with this crew as PAX 2 years before some elements were present: A stewardess sitting on the jumpseat and engaging the pilots in discussions preparing the departure and a quite steep attitude after rotation. Still remember the friendly face of the captain when we left the airplane. May he rest in peace together with all the other 153 victims.
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Post by christrott on Mar 31, 2019 17:39:26 GMT
Interesting direction this discussion is going. Been away a couple days, so catching up. The AF 447 had a programe to activate the stall warnings which were not active below around 40 kts (?) indicated for not generating false warnings while taking off or landing. The pilots of that flight on 31 th of May-1 June 2009 where at least distracted by the stall warning going off while howling back their stick and started crying while pushing. The designers did not foresee, that their AB 330 would be flown ever so slowly and not entering a spin. While the nuisance mode may have played a part, I doubt it was much of one because the stall warnings only worked with the gear down and weight-on-wheels switch engaged. The real problem here was the iced-over pitot probes giving conflicting information and the pilots not having the background and training to deal with a stall at altitude, having been told that for "all stalls" to simply apply power and fly out of it and then had it reinforced by doing all of their stall training in the sim at low altitude either configured for approach or shortly after takeoff. However, at 36,000+ feet, that's not the right way to fly since there isn't the excess of power that exists at and near the surface. I remember departing BOG one morning for MIA on an AA A300-600. I know an ex-Eastern A300 FE and he's told me that even out of relatively short strips like LaGuardia, it was normal to use a LE-only departure configuration for the A300. Apparently the problem is in case of an engine out. With the flaps extended, the plane is more power limited (actually more like drag hindered) and in case of a loss of engine, it becomes difficult to get the plane to climb or accelerate to a "clean" speed. By not using the flaps, it becomes much less of an issue. This seems to be a thing with a lot of the early "high performance" jets with there being a massive change in lift and drag between slats extended and that first notch of flaps. The 727 being a perfect example of this being that you leave the slats out until 220+ knots because of the amount of lift they provide, but you also feel a massive loss of lift as the flaps are pulled up from their Flaps 5/10 departure setting to the Flaps Up/Slats EXT position.
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Post by walterleo on Apr 4, 2019 18:28:13 GMT
Hi friends:
The Ethiopian authorities published today their interim report based on the "Black Boxes" stating: The pilots did everything prescribed by the new amended book, but could not control the airplane. And there is no hint of a demage to the airplane before the event. So BOEING and the FAA should check the entire flight control system. If this is so: Bad news for BOEING and the FAA.
Kind regards
Walter
Walter
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Post by christrott on Apr 5, 2019 14:36:54 GMT
Sorry Walter, they didn't do everything by the "new ammended book". In fact, it looks like they weren't flying the plane properly in the first place. While not noted, this was also the peak of the aircraft's pitch at ~18 degrees. The trace in Appendix 1 & 2 shows that the pilot pitched up on rotation to a maximum of 18 degrees over 9 seconds. At the peak, this is when the AoA split and left stick shaker activated. The pilot then, over 3 seconds, pushed the nose over to a pitch of approx. 8 degrees. If you look at the column movement during that time, he was pulling very aggressively (10 degrees of aft column angle) and then simply released it (0 to -2 degrees) and the nose fell that rapidly (the vertical G trace shows going from +1.5G to +0.5G during this manuever). He then makes manual trim adjustments (see below). Of note here - MCAS hasn't activated yet. This is where it starts to get interesting. They engaged the autopilot, but it disconnected 33 seconds later after the crew retracted the flaps. They still are accelerating (over 250 knots at this point) and slowly climbing. They haven't touched the throttles. They haven't actually tried to work the problem (per the CVR). No acknowledgement of the stick shaker active, no acknowledgement of any problem. In fact, the FO calls out a Master Caution for Anti-Ice and the left AoA vane heat changed state about the same time. This is where I start seeing the crew failing. They aren't dealing with an emergency in their face (the stick shaker) and acting like everything is normal until the AP disconnects 33 seconds later when MCAS activates because the flaps have been retracted. Here the trim is cutout, MCAS attempted to again trim down, but the stab didn't move, meaning the Stab Cut-Out switches were engaged and the electric trim was no longer operating. Here's the real failure. It's been over a minute since they hit the Stab Cut-out. They are only now talking about manually trimming the airplane. At this point, they are at VNE and the overspeed warning is activating. They still haven't touched the throttles. They are still at 94% N1 as they have been since the start of the takeoff roll. The FO then tried to manually trim the plane for 8 seconds before saying it wasn't working. We will never know if he tried to use the handle or not or if he was just trying to use the rim, which wouldn't work at such high speeds. This means that the crew dis-engaged the Stab Cut-Out switches, against the Boeing directives. Additionally, it allowed MCAS to re-activate and it did, moments later, and drove the plane into the ground. The important points of the preliminary recording - 1) The pilots did *NOT* follow the procedures. 2) The pilots never touched the throttles. 3) The pilots never really attempted to correct the problems. They knew the trim was an issue, but never really tried to fix it. They never really addressed the stick shaker activation. They never really reacted to the airspeed climbing above 300 knots. They never reacted to the Overspeed warning. They never actually DEALT with the problem. The report also confirms another item - the FO was not properly trained for this operation. He had 361 TOTAL hours, with less than 100 in aircraft that were not the 737. The guy had been operating as an FO of a Transport-category aircraft for over 100 hours and was *NOT* legally able to be rated as a Commercial Pilot. From the ECAA's own regulations - However, the ECAA has a "Multi-Crew Pilot License" that allows you, with no prior experience, to train to be an FO on a transport-category airplane pretty much by simply being 18 and passing the Airline Transport Pilot ground course. From there, you have to complete what is basically the type-rating course for the airplane you're going to fly and then you get the MCPL license. www.ecaa.gov.et/documents/20181/0/ECAA-AC-PEL002_+PILOTS+AND+FLIGHT+ENGINEERS.pdf/15c3751d-add8-4889-8cde-90bd2fee68f3The lack of real training of these pilots is what worries me more than anything. What the airplane is doing can be fixed - if the crew is properly trained. They weren't. Again.
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Post by walterleo on Apr 5, 2019 19:43:14 GMT
Hi:
From where one knows that the CO did not have a CPL? And with Lion-Air nobody claimed that the pilots where not trained enough. Besides US Navy Pilots land at night jets on aircraft carriers with 300 hours total flight time.
One should find a pilot, who will throw back the throttles while the stick-shaker anouces aproach to stall. AND: There was a saying, that MCAS will switch off by itself over 250 kts?
Think the problem is much more complicated as the black boxes may reveal.
Kind regards
Walter
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Post by christrott on Apr 6, 2019 1:11:25 GMT
There was never anything that said MCAS would shut itself off over 250. It only looks (right now) at AoA and flap position. It only shutoff if the flaps were extended or A/P was engaged.
As for throwing back the throttles - read page 30 of the preliminary report. What does Item 3 specifically state to do? Additionally, check page 33. What does Boeing state may be symptoms of an AoA malfunction? What did they not address? Standard operating procedure for all aircraft is that if you have an instrumentation or system failure on the PF's side, control is transferred to the other pilot. That did not happen. There was an issue that was identified by the crew but they did not fully respond to it. They did not follow the procedure *OR* checklists. So again, they didn't follow Boeing's procedure and that is what led to the crash.
According to the information provided by both the ECAA in prior notices and Ethiopian Airlines, he had gone through Ethiopian Airlines' academy and earned the MCPL. If you read the whole regulation, it is extremely unlikely that he had time to complete the additional requirements to receive a full CPL considering the times listed versus his total time. I only listed the first part of the regulation because I knew the post was already getting long and then posted the link to the full document.
As for your argument about US Navy Pilots (or in fact the Navy pilots of the UK, France, Russia, India, or China) landing on carrier decks - they are trained for very specific and specialized operations and they are not carrying the general public. It has been agreed worldwide that military training is valuable to their post-military flying careers, but it's also been recognized worldwide that there are limitations to that value and thus the requirement that military pilots have to take a knowledge test and then receive a rating based on that test and their total experience. Point is, there's a limit to how much that translates, especially when it comes to flying people for hire. I would think that most military pilots don't expect to step out of their hot-rod fighter jet (if that's where they were) and straight onto the flight deck of a 747. They have a leg up on the guy who's got 300 hours flying Cessnas around his local area when it comes to dealing with stress and other issues, but as far as actually operating the airplane and dealing with emergencies specific to that airplane, they're not really that much better off.
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Post by Herman on Apr 6, 2019 14:35:58 GMT
All this suggests to me, and as I mentioned previously, that another fancy computerized device (MCAS), with the potential of malfunctioning,at a very busy time during takeoff, was added, that IMO was not necessary.
How many stall incidents occurred with the previous model, the 737 NG's, which did not have this MCAS system?? It would be useful to hear the opinions of MCAS, from real world 737 MAX8 Pilots.
Herman
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Post by christrott on Apr 6, 2019 16:11:31 GMT
There are several, but pilot opinions don't matter. MCAS was added because of FAA and EASA regulatory requirements. When Boeing moved the engines forward and up, it introduced an edge case that, by regulation, Boeing was required to address. They did so with MCAS as they felt that using a software fix was better than making further airframe changes to counteract the issue as it would be much more costly and time consuming to do. The problem came into play when the rest of the certification program wasn't followed and the FAA ("short people" as it always is) didn't provide proper oversight to tell Boeing that not including information about it wasn't acceptable. However, I would also say that the FAA's sign-off on not including MCAS in the documentation was also based on the test data not including what would happen in case of an AoA failure, a part that very rarely fails.
The real issue here is that the AoA vane on the left side continues to have a fault, not that MCAS is malfunctioning (necessarily). MCAS is a result of the AoA issue. Boeing is trying to fix the MCAS so an AoA failure won't try to crash the plane, but they are also working in the background to find out why the left AoA vane continues to fail inflight but not on the ground or leave a fault code that can be traced. The AoA vane placement is exactly the same as it has been on all previous 737 versions, so it's not an aerodynamic thing causing the fault, it's something else and that's what really has people baffled. I personally wonder if that aggressive rotation on takeoff that we see with both accident flights has something to do with that part.
The other thing I don't see is who is doing the sim training for Ethiopian. Are they in-house or are they using Airbus as Lion Air does? That could also be a point of commonality in the training failure. Not that Airbus is deficient, but that Airbus has a totally different training and operating philosophy from Boeing and maybe that has something to do with where the failures come in and why the crews have been so ill-equipped to handle them.
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Post by walterleo on Apr 6, 2019 20:30:29 GMT
Hi:
The preliminary conclusions state clearly that the pilots DID follow the Boeing prescribed procedures. In the report is also included the BOEING bulletin of 6 th of November 2018 stating: .... AoA failure can occure in manual flight only. ... it is possible for the stabilizer to reach the nose down limt...
So having enough altitude, time and physical power to hold the stick back and turn various times the trimwheel to neutral after cuting off the two cut out switches it could be possible to save the day. If one or more of these conditions are not fulfilled, the issue reverts to the guardian angels of all on board. I doubt if such a design principle is within the rules of aviation.
Kind regards
Walter
P.S.: One can think also, that time and altitude could be gained by climbing with flaps much higher than fuel-saving dictates. So MCAS could do lesser harm. But the promises of additional fuel saving in the 737 Max evaporate.....at least partly.
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