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Tentative report on FlyDubai plane crash due today (April 19)
A tentative report on the inquiry into the FlyDubai Boeing crash in Rostov-on-Don may be published on April 19, an Interstate Aviation Committee (IAC) spokesman told Interfax on April 18. "The IAC plans to publish a preliminary report on this inquiry on April 19," he said. The Interstate Aviation Committee said earlier that the catastrophic stall of the Boeing passenger jetliner at Rostov airport on March 19 resulted from the pilot's shift of the stabilizer into the 'nose dive' position. While the pilots pushed the control column at the altitude of 900 meters, the plane's stabilizer was moved five degrees to a nose-dive regime, the IAC said. As a result, the plane dived, with up to -1 plunge acceleration. |
Having worked 'Operations' for a number of carriers, both scheduled and charter, there are a number of commercial factors that simply don't make sense and please excuse that I don't dredge back thru some 67 pages regarding which buttons to press etc:
1. The outbound load, on a B737-800, was a mere 55, what was the return booked load like because I've worked for many a scheduled carrier where we'd just be looking for an excuse to cancel a flight with just a 30% booked load and something like 70mph winds at the destination would provide us with that excuse, so: a. Are flydubai a professionally run organisation with trained Operation/Dispatch staff capable of making a judgement call or are they an organisation of tee-shirted muppets calling everybody "sir" whilst serving about as much purpose as a chocolate teapot?, and b. Upon report did the Captain question the destination weather, was he permitted to question the destination weather proposing cancelling the flight or was he not permitted to propose this and/or he already knew what the answer would be? And then, having departed and arrived to his destination and conducted one missed approached he went in to the hold, I appreciate that one doesn't enter a hold planning to stay there for 2 hours or longer, but: a. After 30 minutes, 60 minutes, 90 minutes etc. in the hold "who is calling the shots?". Was a significant weather improvement forecast, or: b. Why didn't they PDQ divert to, perhaps, Krasnodar, to sit it out there (it is acknowledged that an additional sector reduces allowable FDP by 45 minutes), or: c. Simply divert to, perhaps, Krasnodar, dump the pax there for road transportation to Rostov, put some fuel on and return PDQ to DXB empty? As I say there are commercial factors here that don't make sense, who was in charge, managing, this operation or might I already have guessed that it was someone wearing a tee-shirt in charge of this operation? |
Phileas, That sounds like a rhetorical question to me.
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Not intentionally Sciolistes
They departed with a p1ss poor, probably loss making, revenue load to a destination that was, presumably, below weather minima, they were presumably able to legally depart because they had an available alternate. They were already on a 12.25hr nighttime FDP, rather than use their available alternate they flew around in circles for some 2 hours burning up valuable allowable FDP hours, expensive fuel and engine hours. I don't know the allowable nighttime (UAE) FDP for 2 sectors but by this time they would have been up to something like a 14.25hr FDP and they still hadn't achieved anything, they still had the 55 pax on board that they departed with, the destination weather was still sh1te and had the flight not had such a catastrophic end where was it supposed to be heading ... It seems that there was no game plan? |
Phileas,
Welcome the the world that is Flydubai. There never has been much of a game plan really. The operations department is run by our friends from the sub continent who have a "press on regardless" attitude. If the weather is bad, take extra fuel..... and I don't mean enough for 20-30 minutes of holding, I mean 3-4 tons of fuel. It is the same for low pax loads too. I myself, have flown with 0 pax on one leg, and not much more on the return one, and this is not a one off either. Flydubai would rather all flights depart, irrespective of the wx or forecast wx. Having you hold for two hours is nothing here, as it's better than having an a/c diverted where crew and pax need to be put up in a hotel etc. |
20 april 2016
The Interstate Aviation Committee is providing upgrade on the progress of the investigation of the accident involving a Boeing 737-800 registered A6-FDN operated by Flydubai. An interim report (preliminary reference information) is released and available at the IAC website. This interim report (preliminary reference information) has been issued in compliance with 2.4.12 of the Rules of Investigation of Accident and Incidents Involving Civil Aircraft in the Russian Federation as well as 7.4 of ICAO Annex 13. The report contains factual information currently available to the investigation team. The investigation is underway, including collection and analysis of information related to crew training, assessment of crew actions and psycho-emotional status in the course of the accident flight as well as evaluation of the aircraft systems and components operability. The investigation will be completed with a Final Report. The information presented in the Interim Report is preliminary and can be subject to clarification and amendment based on the pertinent examinations. The Report is published in the Russian and English languages. If there is a difference in interpretation between the Russian and English versions, the Russian version will prevail. http://mak-iac.org/upload/iblock/19b...FDN%20(en).pdf |
Our Russian friends are to be congratulated on an excellent start.
PM |
Kulverstukas, the link doesn't appear to work. Perhaps give this one a try:
http://mak-iac.org/upload/iblock/310...FDN%20(en).pdf |
Another link just in case
https://drive.google.com/file/d/0B-u...ZtNUt6MHc/view p.5-6 Both approaches (from the height of about 600 m) were performed with autopilot and autothrottle disengaged in flight director mode without significant heading or altitude deviations from the glideslope. As the crew were proceeding with the approach (as per the FDR and CVR readout), the crew decided to go around again at a height of 220 meters (4,5 km before the runway) and initiated climb with vertical speed of up to 20 mps setting the engines to maximum takeoff/go- around thrust of 101 – 102% (N1). One of the probable causes of the go-around decision could have been the 20-knot increase of indicated speed to as much as 176 knots within 3 seconds, which might have been an indication of a windshear. In the course of the go-around the crew set flaps to 15° and retracted the landing gear. At the height of 1900 ft (approx. 600 m) after reaching the pitch angle of 18° the pilot flying pushed on the control column, which led to a decrease in vertical acceleration of up to 0.5, increase in forward speed and, consequentially, automatic retraction of flaps from 15° to 10° at a speed of over 200 knots. The short-term decrease in engine thrust within 3 seconds resulted in decreasing speed and flaps extension to 15°, although the following crew inputs to regain maximum takeoff/go-around thrust led to speed increase and reiterated automatic flaps retraction to 10°. The flaps remained in the latter configuration until the impact. The pilot flying, by pulling up the control column, continued climbing with a vertical speed of as much as 16 mps. At a height of 900 m there was a simultaneous control column nose down input and stabilizer nose down deflection from -2,5 deg (6,5 units) to +2,5 deg (1,5 units) (the FDR recorded a nose down stabilizer input from the stabilizer trim switch of the control wheel lasting 12 seconds, while the CVR record contains a specific noise of rotation of the trim wheels located on both sides of the central pedestal), as a result the aircraft, having climbed to about 1000 m, turned into descent with negative vertical acceleration of -1g. The following crew recovery actions did not allow to avoid an impact with the ground. At 00:41:49 the aircraft hit the runway about 120 m from the threshold with a speed of over 600 kmph and over 50 degrees nose down pitch. |
12 seconds of nose down trim with the flaps out is game over. My best guess is that would change the in trim speed by well over 100KTS.
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I guess the only remaining question, is whether the question should be "what the hell were they doing/thinking" , or, "what was the machine doing ", & why didn't they, in that case (via opposing input & or stab trim cutout ) stop it.
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I just repost my loose translation from Denis Okan LJ:
1. The first go-around (after which they diverted into the waiting area) was performed due to wind shear. 2. Before the second attempt crew agreed that in case of unsuccessful approach they will divert to alternate with climbing to FL80. 3. The second approach was manual. Vapp was set at 10 above Vref (according to wind check must be 10 lover, but it did not play a role). 4. A/C was not stabilized at 1000ft and below 1000 after a short discussion, the crew began GA. 5. During the whole approach FO, apparently, was more in the contour than PF. He constantly helped Capt., prompted about actions etc. In general, it seems that FO was in leading role. PF was tense, he lacked focus, for example, asking questions, if the height set to 8000 at which FO answered - look, here it is. 6. During the GA the Tower transferred them to Area frequency. At this point, FO was trying to suggest something to PF, but apparently the need for communication with the Area distracted him completely. 7. After that, the situation is unfolding rapidly, FO does nothing but tries to convey information to the PF about his incorrect actions, but the time and height was not enough. |
5. During the whole approach FO, apparently, was more in the contour than PF. He constantly helped Capt., prompted about actions etc. In general, it seems that FO was in leading role. PF was tense, he lacked focus, for example, asking questions, if the height set to 8000 at which FO answered - look, here it is. |
Phileas, Welcome the the world that is Flydubai. There never has been much of a game plan really. The operations department is run by our friends from the sub continent who have a "press on regardless" attitude. If the weather is bad, take extra fuel..... and I don't mean enough for 20-30 minutes of holding, I mean 3-4 tons of fuel. It is the same for low pax loads too. I myself, have flown with 0 pax on one leg, and not much more on the return one, and this is not a one off either. Flydubai would rather all flights depart, irrespective of the wx or forecast wx. Having you hold for two hours is nothing here, as it's better than having an a/c diverted where crew and pax need to be put up in a hotel etc. |
The interim report does clear up a few things that have been debated on the thread so far.
From my reading of it; 1/ Both approaches were flown with no autopilot and no auto throttle using flight directors. 2/ The aircraft was quite light, it departed at 68T so would have been about 54T at the time of the accident ( assuming normal profiles and not accounting for icing etc). 3/ the c of g was not aft, it was well forward. 4/ They carried 10kts on Vref From my calculations Vref would have been 133 kts so Vapp at about 143. The report has full thrust manually set and 18 degrees NU giving 4000fpm climb with airspeed increasing through 200kts and blowback to flap ten. All of that makes perfect sense, it is the performance one would expect out of the machine and why a well rested NG pilot would only set about 85% N1 in these circumstances .......unless of course he had just handed in his notice due to years of fatiguing rosters and it was four in the morning and his brain was so sluggish that he hadn't even thought about what thrust to set in the event of a go-around .....in that case everything might happen so fast that he would struggle to to process it all, he might even be more suseptable to seat of the pants illusions and be quite confused.......but it's all legal of course, must be the pilots fault. Ps it's worth remembering that the same crew conducted a successful missed approach two hours earlier in similar conditions . |
Setting full (maximum) thrust is a Boeing procedure in case of windshear escape maneuver - refer to B737 QRH. When crews are trained in the sim, this action is required from them.
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If one was ever wondering how long the permissible duty time should be, according human performance, through the night, with pre-existing fatigue, here you have it.
The limit would be somewhere between the first approach and the second. An outbound return flight should never have been scheduled in the first place. |
Ps it's worth remembering that the same crew conducted a successful missed approach two hours earlier in similar conditions . With pilots' deadly errors you can always show them operating flawlessly 10 mins, 1 hour, 2 hours, etc before the accident. |
I think it is worth remembering from the point of view that the crew were capable of doing this manoeuvre successfully. To me this means there was likely a change in their performance capabilities over that two hours. ( not really surprising though is it).
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Setting full (maximum) thrust is a Boeing procedure in case of windshear escape maneuver - refer to B737 QRH. c If it was another wind shear go around ( I think the report indicated either a predictive or actual winds hear warning for the first go around) then they got the thrust right but the configuring wrong. If it was a standard go around, it would appear that too much power was used to get the desired performance, the attitude was within cooee. Either way, if the previous rostering, duty length and time of day isn't addressed in a transparent manner in the final report it will be a crying sham/e. Put it this way, if they were truck drivers they would already be in breach of the law regarding fatigue in New Zealand and Australia for not having had minimum rest. |
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