Malaysian Airlines MH370 contact lost
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Ghost phone
With an open mind to all possibilities, the skipper's call from a fraudulently-obtained phone story appears to be gathering momentum...
I'm not suggesting that the Malaysian government is in any way complicit in the disappearance of MH370, but I wouldn't be the least bit surprised if they found some way to leverage it for domestic political advantage. We have already seen attempts to link the incident to the good captain's political alignment.
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Given the quality of the information that has made the current search area the current search area, a single P8 seems to be an appropriate commitment of resources from non-locals.
If and when there's definitely something to see, then a more substantial presence from the airframe and engine manufacturers could be justified.
A game of hunt the faint deep pinger would probably interest most well-equipped navies, with substantial kudos available to the winners; as well as the satisfaction of doing something very concrete for the safety of those millions that take to the air every day.
If and when there's definitely something to see, then a more substantial presence from the airframe and engine manufacturers could be justified.
A game of hunt the faint deep pinger would probably interest most well-equipped navies, with substantial kudos available to the winners; as well as the satisfaction of doing something very concrete for the safety of those millions that take to the air every day.
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GarageYears said:
If it had a digital keypad and someone started entering a new four digit code but did not complete the entry (became incapacitated or just distracted by a bigger problem) does the transponder time-out and go back to the old code or just sit there in standby waiting for the last digit which never comes??
Yes, they do go into standby as soon as the code selector knobs or buttons are active. In the case of the keypad, it releases as soon as the 4th digit is entered, and the rotary has a 3-5 sec timeout.
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For the purpose of this exercise, it is reminded that pilots, a long long time ago at the beginning of their careers, learnt to not just input bearings in an electronic device but also to calculate them by hand (bearings /speeds /distance), in such a way that I would expect any of you pilots to still be able to do the calculations in a second without paper and pencil, possibly in a split second. Without getting into complicated trig, recall that you subtracted various angles, the most common of which are 90°, 180°, 270° and 360°. In between, geometry remnants would kick some memories of angles such as 30°, 45° and their complements.
First of all we don't enter bearings into the FMC. We enter airways or waypoints, that are contained in a verified database, into the FMC. Bearings are barely ever used!
The biggest concern in everyday life regarding angles is that you don't bust your crosswind limitations, and on 99% of days thats not a concern either.
Doing complicated raw data VOR radial intercepts, or even holdings is not something that is done regularly (nor trained regularly) in modern aviation (bar maybe a few companies).
Last edited by 737Jock; 23rd Mar 2014 at 22:30.
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AUS dispatched Ocean Shield
AUS press reported this morning (Monday) that Ocean Shield, an offshore support vessel with an underwater ROV on board and normally based in Sydney has been dispatched.
Its got a way to go, just entering Bass Strait. This link shows her current position
Live Ships Map - AIS - Vessel Traffic and Positions - AIS Marine Traffic
Its got a way to go, just entering Bass Strait. This link shows her current position
Live Ships Map - AIS - Vessel Traffic and Positions - AIS Marine Traffic
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Now the despatch of ROV operating ships indicates the commitment of real money, or at least an absence of other gainful work.
Sounds like evidence that's there's going to be something to find.
Sounds like evidence that's there's going to be something to find.
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The other question is, what are the us going to send that would greatly enhance what is already here, considering they have already sent a P8.
AW
Re the Ocean Shield, sounds like good forward planning to me.
We (as in Aust) have only had it a short while and specifically purchased for Disasters and disaster relief. Heaps of deck space, accommodation, a helipad and ROV, all very useful if they find anything and for taking items from other ships that pick wreckage up.
AW
Re the Ocean Shield, sounds like good forward planning to me.
We (as in Aust) have only had it a short while and specifically purchased for Disasters and disaster relief. Heaps of deck space, accommodation, a helipad and ROV, all very useful if they find anything and for taking items from other ships that pick wreckage up.
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CO detection
Is it safe to assume a) CO couldn't enter cabin (either from known (ie. engines) or unknown (cargo hold fire) combustion sources) and, b) if CO were present, a/c are fitted with appropriate detectors?
Thanks.
Thanks.
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I see the Xue Long is in area already. Got there quick or left a while ago ....
By coincidence, it was in port in Perth and restasked by China a few days ago to join in.
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Isaircrafts the only means?
UK sent a ship; would that bethe only one available?
The US could nearlyblanket the area, but no
Some countries with the most technology are taking an armslength here.
Not customary.
Not by any means. The US cannot be everywhere at every time. If you have not noticed there is a kerfuffule in Crimea that may require US ( and for that matter UK) assets to be deployed as close as they can.
Yes HMS Echo is the only UK ship that can get to that area within a matter of days. Other RN ships could not get there within weeks. How fast do you think ships move?
The US have not provided satellite imagery because the Chinese can see exactly what they see.
UK sent a ship; would that bethe only one available?
The US could nearlyblanket the area, but no
Some countries with the most technology are taking an armslength here.
Not customary.
Not by any means. The US cannot be everywhere at every time. If you have not noticed there is a kerfuffule in Crimea that may require US ( and for that matter UK) assets to be deployed as close as they can.
Yes HMS Echo is the only UK ship that can get to that area within a matter of days. Other RN ships could not get there within weeks. How fast do you think ships move?
The US have not provided satellite imagery because the Chinese can see exactly what they see.
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500N,
Fair enough... if it's a ship dedicated to accident investigation rather than a commercial vessel, then that's not so indicative that there is yet any work for it to do.
Fair enough... if it's a ship dedicated to accident investigation rather than a commercial vessel, then that's not so indicative that there is yet any work for it to do.
I see the Xue Long is in area already. Got there quick or left a while ago ....
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Trigonometry of flight MH370
The following figure shows the Earth from a vantage point above the west coast of Australia. Three lines (semi-ellipses) of longitude are shown in colour. The red one passes through the point on the surface directly below the Inmarsat-3F1 satellite. The green one passes through the last known position (last secondary radar contact) of flight MH370. The red one passes through the two large pieces of debris spotted several days ago by the Australian government. The three points on the Earth's surface are marked with dots in the corresponding colours. The left and right limbs of the Earth do not correspond exactly to lines of longitude. In order to approximately define the visible horizon, I have shown the western-most and eastern-most lines of longitude which are almost fully visible from the selected vantage point.
The co-ordinates of the lines of longitude and the coloured dots are as follows:
Western-most (leftmost) visible longitude = 15 deg E
Co-ordinates of Inmarsat-3F1 = 64.4804 deg E, 0.7495 deg N
Co-ordinates of last known position = 103.5786 deg E, 6.9208 deg N
Co-ordinates of debris sighting = 43.9761 deg S, 90.9603 deg E
Eastern-most (rightmost) visible longitude = 175 deg E
Note the following distances:
Radius of the Earth, to sea level = 6,371 km (kilometers)
Altitude of Inmarsat-3F1 = 35,786 km
Estimated altitude from during silent flight = 5 km
Using trigonometry, one can calculate the distance from the satellite to the airplane:
Distance from Inmarsat-3F1 to last known position = 37,455 km
Distance from Inmarsat-3F1 to debris field = 42,515 km
Now, using a value of 298,000 km/sec for the speed of light, the time taken for a radio signal to make a round-trip from the satellite to MH370 can be calculated as:
... to last known position = 0.251 seconds
... to debris sighted = 0.285 seconds
Several days ago, a spokesman for Inmarsat said that they had observed "the pings lengthening" as the flight progressed. The round-trip times I have just calculated suggest that the round-trip ping duration increased by 34 milliseconds during the silent part of the flight.
One can also calculate the average speed of flight MH370. To do this, one must know the following times:
Time at last known position = 17:21 UTC on March 8, 2014
Time of last satellite ping = 24:11 UTC, just after midnight
Subtracting the latter from the former gives the time of silent flight as 6.83 hours
The distance flown by MH370 during its silent flight can be calculated using the angle enclosed by two of the rays shown in the figure. The first is the ray from the Earth's center (the black dot) to the last known position (the green dot). The second ray extends from the Earth's center to the debris field (the red dot). The enclosed angle is 52.16 degrees. Assuming flight MH370 flew a great circle route, this enclosed angle represents 52.16 / 360 = 14.49% of a complete circle. Since the Earth's radius is 6,371 km, the Earth's circumference is 2 times pi times the radius, or 40,030 km. MH370 flew 14.49% of this circumference, or a distance of 5,800 km. It flew this distance in 6.83 hours, at an average speed of 5,800 km / 6.83 hours = 849 kilometers per hour. This can be converted into knots at a rate of 0.54 knots per km, to obtain 460 knots.
References:
a. Telecom, Media and Finance Associates, Inc. reports that the pings from MH370 were exchanged with the Inmarsat-3F1 satellite at 64E longitude.
b. Home - Inmarsat states that their satellites are in geostationary orbit at an altitude of 35,786 km (22,236 miles) above sea level.
c. Online Satellite Calculations states that the location of Inmarsat-3F1 at 22:51 UTC on March 22, 2014, was longitude 64.4804 deg E and latitude 0.7495 deg N. [As the tilt of the Earth changes during the seasons, geostationary satellites drift above and below the equatorial plane. Since we are quite close to the Equinox now, the satellite is quite close to the Equator. I have neglected the drift which has occurred during the last 14 days.]
d. Wikipedia reports that the last known position of MH370, defined as its last secondary radar contact, was longitude 103 deg 34 min 43 sec E and latitude 6 deg 55 min 15 sec N at 17:21 Zulu on March 8, 2014. The same site reports that the final satellite ping was received at 00:11 Zulu on March 9, 2014.
e. A satellite photograph has been copied onto many sites. It is labeled as "Australian Government, Department of Defence, Mar 16/14" and the source of the photograph (Digital Globe) is given as well. Figures overlaid on the photograph show the debris at longitude 90 deg 57 min 37 sec E and latitude 43 deg 58 min 34 sec S.
f. Wikipedia states that the mean radius of the Earth is 6,371 km (3,959 statute miles).
g. I have assumed that the airplane was at an altitude of 5,000 meters both at its last known position and at the start of its descent into the Australian debris field.
The co-ordinates of the lines of longitude and the coloured dots are as follows:
Western-most (leftmost) visible longitude = 15 deg E
Co-ordinates of Inmarsat-3F1 = 64.4804 deg E, 0.7495 deg N
Co-ordinates of last known position = 103.5786 deg E, 6.9208 deg N
Co-ordinates of debris sighting = 43.9761 deg S, 90.9603 deg E
Eastern-most (rightmost) visible longitude = 175 deg E
Note the following distances:
Radius of the Earth, to sea level = 6,371 km (kilometers)
Altitude of Inmarsat-3F1 = 35,786 km
Estimated altitude from during silent flight = 5 km
Using trigonometry, one can calculate the distance from the satellite to the airplane:
Distance from Inmarsat-3F1 to last known position = 37,455 km
Distance from Inmarsat-3F1 to debris field = 42,515 km
Now, using a value of 298,000 km/sec for the speed of light, the time taken for a radio signal to make a round-trip from the satellite to MH370 can be calculated as:
... to last known position = 0.251 seconds
... to debris sighted = 0.285 seconds
Several days ago, a spokesman for Inmarsat said that they had observed "the pings lengthening" as the flight progressed. The round-trip times I have just calculated suggest that the round-trip ping duration increased by 34 milliseconds during the silent part of the flight.
One can also calculate the average speed of flight MH370. To do this, one must know the following times:
Time at last known position = 17:21 UTC on March 8, 2014
Time of last satellite ping = 24:11 UTC, just after midnight
Subtracting the latter from the former gives the time of silent flight as 6.83 hours
The distance flown by MH370 during its silent flight can be calculated using the angle enclosed by two of the rays shown in the figure. The first is the ray from the Earth's center (the black dot) to the last known position (the green dot). The second ray extends from the Earth's center to the debris field (the red dot). The enclosed angle is 52.16 degrees. Assuming flight MH370 flew a great circle route, this enclosed angle represents 52.16 / 360 = 14.49% of a complete circle. Since the Earth's radius is 6,371 km, the Earth's circumference is 2 times pi times the radius, or 40,030 km. MH370 flew 14.49% of this circumference, or a distance of 5,800 km. It flew this distance in 6.83 hours, at an average speed of 5,800 km / 6.83 hours = 849 kilometers per hour. This can be converted into knots at a rate of 0.54 knots per km, to obtain 460 knots.
References:
a. Telecom, Media and Finance Associates, Inc. reports that the pings from MH370 were exchanged with the Inmarsat-3F1 satellite at 64E longitude.
b. Home - Inmarsat states that their satellites are in geostationary orbit at an altitude of 35,786 km (22,236 miles) above sea level.
c. Online Satellite Calculations states that the location of Inmarsat-3F1 at 22:51 UTC on March 22, 2014, was longitude 64.4804 deg E and latitude 0.7495 deg N. [As the tilt of the Earth changes during the seasons, geostationary satellites drift above and below the equatorial plane. Since we are quite close to the Equinox now, the satellite is quite close to the Equator. I have neglected the drift which has occurred during the last 14 days.]
d. Wikipedia reports that the last known position of MH370, defined as its last secondary radar contact, was longitude 103 deg 34 min 43 sec E and latitude 6 deg 55 min 15 sec N at 17:21 Zulu on March 8, 2014. The same site reports that the final satellite ping was received at 00:11 Zulu on March 9, 2014.
e. A satellite photograph has been copied onto many sites. It is labeled as "Australian Government, Department of Defence, Mar 16/14" and the source of the photograph (Digital Globe) is given as well. Figures overlaid on the photograph show the debris at longitude 90 deg 57 min 37 sec E and latitude 43 deg 58 min 34 sec S.
f. Wikipedia states that the mean radius of the Earth is 6,371 km (3,959 statute miles).
g. I have assumed that the airplane was at an altitude of 5,000 meters both at its last known position and at the start of its descent into the Australian debris field.
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Deployment of ADV Ocean Shield
Bear in mind that the Ocean Shield is not an especially fast vessel (RAN lists its speed as 16 knots; as-built it was much happier at 12 knots) so the voyage from its base in Sydney to Fremantle is going to take the better part of six days. Add bunkering time in Fremantle, and another three or four days to get to the search area, and the wrong end of the 30-day pinger life of the FDR is looking unpleasantly close.
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If you have a look at Xue Long's current position and using the "density" tool on the left, move the slider for all traffic to the right, you will see what appears to be where other ships have been searching.
Live Ships Map - AIS - Vessel Traffic and Positions - AIS Marine Traffic
Live Ships Map - AIS - Vessel Traffic and Positions - AIS Marine Traffic
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ADS-b data anomaly - questions for T7 pilots / MX'ers
I worked on ATC software development in the infancy of ADS-B, I haven't been involved for sometime but -
LFRT posted the raw ADS-B data recorded by FR24 and others.
I am assuming that the raw data presented reflects directly what was received by the ADS-b ground station.
It is the last two transmissions that I find of interest.
ADS-b data is primarily derived from GPS, however there is a requirement that the altitude data should correspond to that displayed to the pilot, so at cruise it will be pressure altitude.
I believe that because of this requirement the altitude data is not generated in the ADS-b equipment, but provided externally via a data bus from the pressure altimeter/FMC?.
The last two ADS-b transmission do not have any altitude data (it has presumably been set to zero as there is no valid data).
All previous messages contained credible altitude data.
IMHO there is no physical control that would enable just a single field of an ADS-b message to be selectively suppressed and even if there was for what purpose?
If, as seems to be accepted, the SSR/ADS-b was disabled by someone on the flight deck, how was suppression of altitude data accomplished?
The other possibility is of course that the source of the pressure altitude (altimeter/FMC?) failed / was disabled just before the SSR/ADS-b.
So T7 pilots/MX'ers
Is there some way to suppress altitude output? and if so why would someone want to do that when he is disabling the SSR/ADS-b.
Why wouldn't the ADS-b switch to an alternate altimeter, or is a manual input required?
Are the SSR/ADS-b and pressure altimeter on the same CB?
What would be the consequences of losing all pressure altimeters?
LFRT posted the raw ADS-B data recorded by FR24 and others.
Following is all the ADS-B data i could gather from 1642 to 1721 UTC :
255 cue points with time, altitude and speed data (and discontinued lat/long, climb rate and squawk data).
.
.
.
SOURCES/METHOD USED :
- "FR24 Gr" = FlightRadar24 graph (MH370 - Malaysia Airlines - Flight history - Flightradar24). The raw figures (time, alt & speed) for the 185 cue points of the FR24 graph are included in the page's source code, all i had to do was grab them and translate them in the right units.
- "FR24 Pn" = FlightRadar24 "pinned" page (same url). The data you get each time you press the FWD button. Adds location and heading to some of the 185 "FR24 Gr" points.
- "GE" = Google Earth. For the first "FR24 Pn" points (just after takeoff, in the 327° straight line), i got the lat and long data from Google Earth. Presumably it can be done with every other "FR24 Pn" cue point, that's why i marked their missing lat/long data with a "*"
- "FR24 Pb" = FlightRadar24 "playback" page (Flightradar24.com - Live flight tracker!). Oddly enough, the points are not the same as in the "pinned" page. And these ones also include the climb rate, the squawk and the data feeder (registered ADS-B receiver which the data came from)
- "FA" = FlightAware data (Registre de suivi des vols ? MAS370 ? 08-03-2014 ? WMKK / KUL - ZBAA / PEK ? FlightAware). No squawk data on this one, and some minor discrepancies when compared to FR24 heading and velocity data.
- "PF" = PlaneFinder. 3 additional cue points, still better than nothing.
Once all this data collected, i ordered them by growing altitude until FL350, and adjusted the remaining cue points, based on their timestamp (feel free to interpolate the points where seconds are replaced by XX).
T[UTC];LAT[°];LONG[°];HDG[°];ALT[ft];SPD[kts];RoC[ft/mn];Squawk;ADS-B feeder;Data Source
.
.
.
17:20:22;;;;35000;471;;;;FR24 Gr
17:20:33;;;;35000;471;;;;FR24 Gr
17:20:49;;;;35000;471;;;;FR24 Gr
17:20:XX;6,9300;103,5900;040;0;471;0;2157;F-WMKC1;FR24 Pb
17:21:XX;6,9700;103,6300;040;0;471;0;2157;F-WMKC1;FR24 Pb
255 cue points with time, altitude and speed data (and discontinued lat/long, climb rate and squawk data).
.
.
.
SOURCES/METHOD USED :
- "FR24 Gr" = FlightRadar24 graph (MH370 - Malaysia Airlines - Flight history - Flightradar24). The raw figures (time, alt & speed) for the 185 cue points of the FR24 graph are included in the page's source code, all i had to do was grab them and translate them in the right units.
- "FR24 Pn" = FlightRadar24 "pinned" page (same url). The data you get each time you press the FWD button. Adds location and heading to some of the 185 "FR24 Gr" points.
- "GE" = Google Earth. For the first "FR24 Pn" points (just after takeoff, in the 327° straight line), i got the lat and long data from Google Earth. Presumably it can be done with every other "FR24 Pn" cue point, that's why i marked their missing lat/long data with a "*"
- "FR24 Pb" = FlightRadar24 "playback" page (Flightradar24.com - Live flight tracker!). Oddly enough, the points are not the same as in the "pinned" page. And these ones also include the climb rate, the squawk and the data feeder (registered ADS-B receiver which the data came from)
- "FA" = FlightAware data (Registre de suivi des vols ? MAS370 ? 08-03-2014 ? WMKK / KUL - ZBAA / PEK ? FlightAware). No squawk data on this one, and some minor discrepancies when compared to FR24 heading and velocity data.
- "PF" = PlaneFinder. 3 additional cue points, still better than nothing.
Once all this data collected, i ordered them by growing altitude until FL350, and adjusted the remaining cue points, based on their timestamp (feel free to interpolate the points where seconds are replaced by XX).
T[UTC];LAT[°];LONG[°];HDG[°];ALT[ft];SPD[kts];RoC[ft/mn];Squawk;ADS-B feeder;Data Source
.
.
.
17:20:22;;;;35000;471;;;;FR24 Gr
17:20:33;;;;35000;471;;;;FR24 Gr
17:20:49;;;;35000;471;;;;FR24 Gr
17:20:XX;6,9300;103,5900;040;0;471;0;2157;F-WMKC1;FR24 Pb
17:21:XX;6,9700;103,6300;040;0;471;0;2157;F-WMKC1;FR24 Pb
It is the last two transmissions that I find of interest.
ADS-b data is primarily derived from GPS, however there is a requirement that the altitude data should correspond to that displayed to the pilot, so at cruise it will be pressure altitude.
I believe that because of this requirement the altitude data is not generated in the ADS-b equipment, but provided externally via a data bus from the pressure altimeter/FMC?.
The last two ADS-b transmission do not have any altitude data (it has presumably been set to zero as there is no valid data).
All previous messages contained credible altitude data.
IMHO there is no physical control that would enable just a single field of an ADS-b message to be selectively suppressed and even if there was for what purpose?
If, as seems to be accepted, the SSR/ADS-b was disabled by someone on the flight deck, how was suppression of altitude data accomplished?
The other possibility is of course that the source of the pressure altitude (altimeter/FMC?) failed / was disabled just before the SSR/ADS-b.
So T7 pilots/MX'ers
Is there some way to suppress altitude output? and if so why would someone want to do that when he is disabling the SSR/ADS-b.
Why wouldn't the ADS-b switch to an alternate altimeter, or is a manual input required?
Are the SSR/ADS-b and pressure altimeter on the same CB?
What would be the consequences of losing all pressure altimeters?
Last edited by Control Eng; 24th Mar 2014 at 00:01.