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Originally Posted by Lonewolf_50
(Post 8535787)
Ian W, well answered on why there is global aviation industry value in finding out what physical evidence may tell about what happened, and a few hints at who and how.
Whose dime? My offered suggestion is Malaysia, and the Flag Carrier Airline of that country. Put the burden of cost on those with the formal oversight for safe and proper operations of their various aircraft and crews. This may sound harsh, but I think is realistic and just. |
Other officials involved in the crash investigation have suggested that either of the plane’s pilots might have commandeered the aircraft in order to commit suicide |
Improved tracking
'Perhaps the issue of who pays should be given more priority in the discussions that are currently in progress in the pan-national aviation organizations that are all coming up with various bureaucratic regulations on tamper-proof aircraft tracking.'
Forgive me, but something I have been wondering - was there a tangible demand for this sort of facility prior to March this year? Or is it a very recent phenomenon that has come about in the light of this event - a reaction to it specifically, rather than an idea that was around for some time and just required a 'push' in order to get to the top of the list? I'm afraid I don't have the background knowledge to put this into context. (not suggesting anything conspiratorial, by the way) Thank you. |
Would they not have made a radio call if the above were true. It appears the aircraft flew normally and was not damaged or in distress. Looks like from the precision of the routing it was a newly programmed route with LNav engaged.
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Originally Posted by susier
(Post 8537017)
'Perhaps the issue of who pays should be given more priority in the discussions that are currently in progress in the pan-national aviation organizations that are all coming up with various bureaucratic regulations on tamper-proof aircraft tracking.'
Forgive me, but something I have been wondering - was there a tangible demand for this sort of facility prior to March this year? Or is it a very recent phenomenon that has come about in the light of this event - a reaction to it specifically, rather than an idea that was around for some time and just required a 'push' in order to get to the top of the list? This was not done as the airlines did not want to spend the extra money they thought they would be paying for SATCOM transmissions. After all a crash in the sea without position reports was very rare and the chances of that happening to their aircraft meant that it wasn't worth it. Anyway the search costs are not borne by the airline. So the beancounters were not going to pay. Along comes MH370. This is a real trigger for the regulators to get their act together as people are now saying- look its happened again! Perhaps not quite fair as apart from both (we think both) ditching in the sea there are no other commonalities. But the regulators (together with keen avionics marketers ) are now pushing for tamper proof tracking that would meet the AF447 recommendations _and_ prevent the loss of position reporting of MH370. The problem is that we still don't know why or what MH370 did whatever it did. Perhaps all that is needed is to set the ADS-C period to say 4 minutes and ACARS to always report over SATCOM certain emergencies. This would provide all the tracking and information needs for 99% of incidents including MH370 without any new avionics and thanks to INMARSAT's offer of 'free' tracking it would not cost the airlines. This is why it would be really really helpful to find the airframe. |
New ATSB report
New report from ATSB announced at press conference today (June 26)
http://www.atsb.gov.au/media/4911984...370-report.pdf |
PolAgnostic, if my reading of diagram 18 is correct then you are incorrect.
The tip of the arrow and the regular spacing of the ping times are a function of graphic design and not attempting to show the position of the aircraft at each ping. What is relevant is the interval between displayed ping arcs. Whilst the greatest interval is the penultimate one, this represents 90 minutes and not the previous 60 minutes. Note also the interval after 1825 is also 90 minutes and not 60. |
The orange area of search in the report page 47 is over the direct track from MEKAR IGREX and the FIR at 92E towards Wilkins Runway YWKS. Is there any coincidence? Can someone tell me whether YWKS appears in the B777 FMC database, it certainly complies with the criteria that I understood was used as the runway is in excess of 4000m long
It doesn't appear from my quick reading of the relevant pages that an LNAV constant track from those waypoints towards Wilkins has been analyised. |
How do we know that an emergency descent was not initiated, making the groundspeed lower and the range much less? The latest ATSB report doesn't appear to discuss that possibility?
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Can someone tell me whether YWKS appears in the B777 FMC database, it certainly complies with the criteria that I understood was used as the runway is in excess of 4000m long |
Compressor Stall, I'm sure you are right, I have taken my information on the Wikipedia list of Antartica runways. What is important is that the Boeing database generally records all runways over a certain length in the database. From memory it is somewhere around 5 to 6000 ft.
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Statistical Search Methods
Has any information been published on which, if any, mathematical/statistical models have been deployed in the MH370 search?
Bayesian methods were mentioned back in this post but only in relation to AF447. |
How do we know that an emergency descent was not initiated, making the groundspeed lower and the range much less? The latest ATSB report doesn't appear to discuss that possibility? Edit: The assumptions are on page 21. |
A very good and comprehensive report. It shows how professional the working groups are trying to resolve the problems.
The only thing I am missing is: in which AP lateral mode (mag track? mag hdg?) would the 777 have flown, if LNAV along waypoints was ruled out? A "direct to" is unlikely as the curved path does not seem to correspond to a great circle path. |
Originally Posted by Shadoko
(Post 8534688)
- is it known how the BTO data published ("raw data" PDF) were measured? It is evident that the digits are not the whole go and back signal time.
See page 23 of: http://www.atsb.gov.au/media/4911984...370-report.pdf |
Three Miles
The only thing I am missing is: in which AP lateral mode (mag track? mag hdg?) would the 777 have flown, if LNAV along waypoints was ruled out? |
Very interesting stuff!
After a quick reading, a probable stupid question: at the last page (58), table 6: Downlink Doppler: -79.5 -75.1 -70.7 Hz Satellite movement, which I understand as the Doppler of the down link (the DeltaFdown variable of page 56), so between 3F-1 and Perth Why does this value change with the latitude of the aircraft? Does this value include the error for the faulty compensation from the aircraft because the satellite is assumed to be in another location it actually is? |
From page 34 of the ATSB report just released:
End of flight scenario Note: Given the imprecise nature of the SATCOM data, it was necessary to make some assumptions regarding pilot control inputs in order to define a search area of a practical size. These assumptions were only made for the purposes of defining a search area and there is no suggestion that the investigation authority will make similar assumptions. The limited evidence available for MH370 was compared with the accident classes listed previously. In the case of MH370, there were multiple redundant communications systems fitted to the aircraft (3 x VHF radios, 2 x HF radios, SATCOM system, 2 x ATC transponders). However, no radio communications were received from the aircraft after 1719.29, 7 hours prior to the last SATCOM handshake at 00:19. Analysis of the SATCOM data also showed that there were probably no large changes to the aircraft’s track after approximately 1915, about 5 hours prior to the last SATCOM handshake. Given these observations, the final stages of the unresponsive crew/ hypoxia event type appeared to best fit the available evidence for the final period of MH370’s flight when it was heading in a generally southerly direction: loss of radio communications long period without any en route manoeuvring of the aircraft a steadily maintained cruise altitude fuel exhaustion and descent This suggested that, for MH370, it was possible that after a long period of flight under autopilot control, fuel exhaustion would occur followed by a loss of control without any control inputs. Note: This suggestion is made for the sole purpose of assisting to define a search area. The determination of the actual factors involved in the loss of MH370 are the responsibility of the accident investigation authority and not the SSWG. Here's a New York Times article with an overview of the ATSB search area report: http://www.nytimes.com/2014/06/27/wo...light-370.html This discussion of possible MH370 waypoint and airway routing is on pages 36-37 of the ATSB report: MH370 Radar data showed that after take-off MH370 tracked in accordance with its flight-planned route to waypoint IGARI and then turned right towards waypoint BITOD. Secondary radar data was lost shortly afterwards. Primary radar data then showed that MH370 deviated from its flight-planned route. Primary radar data showed that the aircraft tracked along the Malacca Strait. During this time the aircraft passed close to waypoints VAMPI, MEKAR, NILAM and possibly IGOGU along a section of airway N571. Southern air routes/waypoints Air routes and waypoints were then examined to see if there was any correlation with the possible southern tracks for MH370 obtained from the analysis of the SATCOM data. Relevant southern air routes that MH370 may have intersected/traversed were N509, N640, L894 and M641. Waypoints associated with these air routes were also considered as possible points on the MH370 flight path. N509 ELATI 0200.0S 08957.7E PORT HEDLAND N640 TRIVANDRUM BIKOK 0817.0N 07836.0E COLOMBO LEARMONTH MOUNT HOPE ADELAIDE L894 KITAL 2003.0N 06018.0E MALE SUNAN 0028.7S 07800.0E DADAR 0200.0S 07927.1E PERTH M641 MADURAI BIKOK 0817.0N 07836.0E COLOMBO COCOS IS The waypoints at MUTMI and RUNUT were also considered as possible points that MH370 may have crossed. However ground tracks through these points did not correlate well with the most favoured paths generated through the analysis of the BFO and BTO data. Air routes/ waypoints summary Although waypoints and air routes were examined and compared to possible tracks derived from analysis of the SATCOM data, there was insufficient evidence to positively determine whether MH370 intersected any waypoints associated with published air routes in the Southern Indian Ocean. |
http://www.nytimes.com/2014/06/27/wo...-370.html?_r=0
Advocates of the hypoxia theory argue that pilot suicide cases tend to involve pilots who crashed their planes suddenly, not after hours of flight. A clinical psychologist advising the investigation has been very skeptical of the suicide theory, saying it would be highly unusual for a suicidal person to proceed with such a deadly plan over many hours, investigators said. |
Gysbreght: about the deltaFdown.
In my satellite model (which happens to differ slightly from the table 4 page 56 (0.5 to 1.5 km)), if I use a 4GHz value for the frequency, I have (at 17:05) a -82.7 BFO from the speed of the sat relative to "Perth" GES (mine is -31.80 115.89). Relative speed: ~6.2m/s. I have a -71.4 value at 17:27. To have -71,4 at 17:05, I have to use 3.45GHz for the downlink frequency. All this with a very simple model and using a spherical Earth. What is sure, IMHO, is that the aircraft have nothing to do with that [part of] BFO. |
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