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-   -   Air Asia Indonesia Lost Contact from Surabaya to Singapore (https://www.pprune.org/rumours-news/553569-air-asia-indonesia-lost-contact-surabaya-singapore.html)

CDN_ATC 28th Dec 2014 21:28

The few of us who are professionals in the field of ATC makes most of this thread unbearable to read

No not even pilots, no matter their flight experience have nothing more than a basic understanding of ATC systems, so please stop purporting an expertise level of understanding because you may be an experience pilot

I would never purport to be an aircraft expert, but due to my profession we have some associated knowledge just like pilots have of ATC.

There is some pure speculative bull**** about how ATC systems work, and it's obvious, outside of the few ATCOs on here, nobody has much of a clue what they are talking about.

I seriously doubt that area is entirely covered with PSR, SSR yes, but PSR has a range of 80-100NM only, and PSR sites are rare in comparison.

Even OTHR didn't find MH370 and I doubt it will help here either.

Pabloako 28th Dec 2014 21:28

Here are a couple of satellite images from 27 Dec 23:30z. Nothing magical, just MTSat images, zoomed in a bit and false colour added.

Taken from CabooltureWeather , more focus on Australia though.

https://cwaws.s3.amazonaws.com/mtsat..._2332zIRFC.jpg

https://cwaws.s3.amazonaws.com/mtsat...14_2330zIR.jpg

tartare 28th Dec 2014 21:34

The suggestion Nuclear Weapon makes is feasible.
It is what as known as a wireless mesh network.
Every aircraft becomes a node in said network.

allthecoolnamesarego 28th Dec 2014 21:41


23 noshows is not unusual for a LCC carrier in S.E Asia especially for an 0530 Lt departure.
Media reports say it left 2 hours ahead of planned ETD.
A family of 11 didn't get the email/text with the new ETD.

May account for the high number (the other 12 no shows)

terminus mos 28th Dec 2014 21:45

I work for an oil and gas company. We have several large modern helicopters contracted to fly our workforce offshore, up to 16 passengers at a time, 250nm offshore in tropical weather. We have a Honeywell satellite tracking system fitted to every helicopter. It transmits LAT/LONG, HDG, ALT and GS at 2 minute intervals and shows the track of the flight as a crawling icon. I can track flights in real time from any PC.

Sallyann1234 28th Dec 2014 21:49


How do you reliably define those last two events in reality, and rapidly enough?

It does automatically, that means more faster and accurate than humans can do. Simple, based on exceeding of pre-estabilished parameters.
Ah yes! Automatically - I should have thought of that. Just fit an automatic and we are good to go. :}

In the current case, the flight requested a course change to avoid CB - a routine procedure in the tropics. How does your automatic system deal with this? Does the 'automatic' send out a bunch of FDR data for every course and height change, or do the crew press an 'Ignore' button before they turn?

The aircraft already has many "more faster and accurate than humans can do" systems on board, "based on exceeding of pre-estabilished parameters. " and they have not saved it. But this "simple" system is going to work in an emergency...

As terminus says, basic position data is routine. Anything more takes heavy bandwidth.

mixture 28th Dec 2014 22:10


It is what as known as a wireless mesh network.
Every aircraft becomes a node in said network.
Satellite, mesh network, whatever nonsense people wish to dream up, the answer is the same.....

Given the limited number of scenarios in which it would be useful, and the rarity of the scenarios, how on earth do you think the manufacturers are going to convince the airlines to (a) pay for the equipment and its installation it across entire fleets (b) Continue paying operational costs to keep the equipment running just incase some rare event occurs given that there are already other mechanisms in place to monitor aircraft.

Its simple, you have to draw a line in the sand somewhere. The methods in use today to monitor aircraft are perfectly good for 99.9999999999% of however many flights that take place every year on this planet !

Do you really think there is any point expending an inordinate amount of man-power and significant money for the 0.0000000001% that may or may not encounter an issue ?

I mean seriously, compared to the number of flights globally ever the same period how many untrackable instances have we had over the last 10 years ? 20 years ?

And then there's the obvious questions about electrical faults, mid-air breakups etc. putting a great big spanner in these dreams people are coming up with....

There may well be other areas of aviation safety where money and man-power would be well spent ..... but this aint' one of them !

crewmeal 28th Dec 2014 22:12

It would be good if news agencies showed pictures of the correct aircraft. Tonight's ITN news showed an Air Asia 787.

http://s13.postimg.org/5p58hok6f/108...17318777_n.jpg

_Phoenix_ 28th Dec 2014 22:15


In the current case, the flight requested a course change to avoid CB
- by turning the heading knob :ugh: nothing abnormal here, obviously a routine with crew responsive and in control

On the other hand, if the A/C changes speed, altitude, course dramatically due to stall, AOA or pitot tubes malfunctions or departing the normal law then there worth to stream "heavy data"



basic position data is routine.
. Car's GPS do more than that.

peekay4 28th Dec 2014 22:22


There is some pure speculative bull**** about how ATC systems work, and it's obvious, outside of the few ATCOs on here, nobody has much of a clue what they are talking about.

I seriously doubt that area is entirely covered with PSR, SSR yes, but PSR has a range of 80-100NM only, and PSR sites are rare in comparison.

Even OTHR didn't find MH370 and I doubt it will help here either.
According to an Indonesian Air Force spokesman, at least portions of the flight was tracked by an long-range early warning (E/W) military radar operating on Belitung Island (very close to the flight's last known position).

The radar is part of a network operated by Indonesia's National Air Defense Command. I believe the E/W radar at Belitung is an older Thomson-CSF unit from the 1980s, but even they have an operating range in excess of 200 NM.

Capn Bloggs 28th Dec 2014 22:22


Originally Posted by Mixture
how on earth do you think the manufacturers are going to convince the airlines to (a) pay for the equipment and its installation it across entire fleets (b) Continue paying operational costs to keep the equipment running just incase some rare event occurs.

Got nothing to do with convincing anybody. If such a system was deemed necessary, it would be mandated by the authorities for all players. Add $5 to the cost of a ticket. So what? If you knew the angst that MH 370 has caused and the cost of the searches (still on-going) others would be more conducive to the idea. We're not talking about HD streaming of a different video to every pax seat here.

It is rather pathetic that in this day and age we can lose a 777...

Sallyann1234 28th Dec 2014 22:26


Car's GPS do more than that.
And that's receive only :ugh:

You have convinced me to discontinue this discussion.

Blacksheep 28th Dec 2014 22:43

30 Mbs is too much. It's a typo for 30 Kbs.

As for communications - they only work while the aircraft is flying normally. Once you have an accident they stop. Period. If an ELT survives in operational condition, it will transmit it's location but that's about it after the event. In this incident, ADS-B is reported to have been working up to the time contact was lost.

_Phoenix_ 28th Dec 2014 22:47


Car's GPS do more than that.
And that's receive only

You have convinced me to discontinue this discussion.
out of your knowledge there are products that use 2 way satellite communication through Iridium network as emergency rescue beacon or anti theft

Agree!

NSEU 28th Dec 2014 22:49

@NuclearWeapon


The black box will send out the last position reading in lat and long format to a distress box on any aircraft within say 100 miles.
Unfortunately, the black box is currently not connected to a radio transmitter.

Read the Malaysian Airlines thread. It's all been discussed before:

ELT (electronic locator transmitter): activated with high g's. Fuselage mounted antenna. Battery powered. Will not work underwater (uses VHF and UHF(satellite) frequencies). More useful for crashes on land. Satellite comms can be impeded by metallic structures (does your mobile phone always work indoors?). Transmissions are generally line-of-sight. If you're in a deep valley, you may not have a clear view of the satellite. Thunderstorms can also interfere with the signal. Can be destroyed by fire or very hard impacts.

Black boxes (CVR/FDR). Located inside the fuselage. Not connected to antennas, but will transmit an ultrasonic signal when in contact with water. Ultrasonics can be detected by sensors placed in the water by search teams. Stop recording when certain aircraft electrical busses are unpowered (doesn't help if aircraft power is lost in flight as would happen in a break up )

Portable beacons: In stowages throughout the cabin). Battery-powered. Usually removed from stowages and activated by crew after a survivable impact with land/water. Automatically activated by contact with water. Will not work underwater (VHF) and won't work very well if stuck in the fuselage (Google Faraday Cage).

Satellite communication systems: Usually found on larger aircraft for various reasons. Can use small antenna (for data transmission), but for reliability and voice transmission, large fuselage-mounted antenna are used. These require aircraft main bus electrical power and, of course, a functioning navigation system, for transmitting position information.

ACARS: Is capable of using Satellite or VHF to send position information (see limitations above). However, for economy reasons, this data is not transmitted continuously.

We don't need transmitting black boxes. We just need passengers to pay more for their tickets and use existing technology ;)

Ian W 28th Dec 2014 22:54

As CDN ATC has said, some of this thread makes uncomfortable reading.

All widebody aircraft are initially equipped with FANS 1/A (Future Air Navigation System [well it was future in 1980]). FANS 1/A provides for ACARS links to FOC, Automated Dependent Surveillance - Contract (ADS-C) to up to 5 recipients both FOC and ATC- who can contract with the aircraft electronics what they want to be sent and when- without the crew knowing. And of course FANS 1/A provides Controller Pilot Data Link Communication (CPDLC) which is a relatively primitive set of control commands and responses over datalink.

ADS-C is normally set to either 4 minute or 10 minute reporting intervals depending on the RNP requirement of the route, or is set to just report at filed waypoints and level changes i.e. top/bottom of climbs and descents. ADS-C will normally provide aircraft ID, altitude, ground speed, Mach no, GPS position and time and other information. INMARSAT has recently announced that use of ADS-C will be FREE for tracking aircraft. INMARSAT is a geostationary set of satellites which have been updated and provide up to 250Kbs for both data and voice over IP - see Swift Broadband SwiftBroadband - Inmarsat Iridium Next is a low earth orbit constellation that gives complete coverage including the poles. ADS-C can be transmitted in the same way over Iridium with each aircraft having a dedicated connection-oriented link (effectively the Iridium satellites are like orbiting cellphone base stations. Iridium next can support burst data up to 512Kbs up and 1.5Mbs down https://www.iridium.com/About/Iridiu...echnology.aspx

Now neither of these systems would support continual streaming of FOQA or DFDR/CVR data but they could be triggered to accept streamed data in an emergency.

There are other systems such as Outerlink, used by helicopters in the Gulf of Mexico (and trucks in North America), that effectively receives a position report and other information every 2 minutes or so for transmission to the FOC, and a continuous stream of position reports if the pilot selects emergency.

Iridium is also hosting a system called AIREON which is an independent payload on the Iridium Next satellite constellation that will receive ADS-B transmissions from aircraft. ADS-B Out is being mandated in most regions of the world and it is expected that at least in the more sparely flown areas AIREON will be able to provide ADS-B surveillance cover otherwise unavailable to ATC/FOC.

It can be seen therefore that there are sufficient enablers being put into the space segment that tracking an aircraft and getting a compressed 'important issues' data stream is completely possible at little cost. The basic tracking is now available FREE and all aircraft either have the capability or can have it cheaply retrofitted. ADS-C and ADS-B are mandated for many FIR/UIRs.

Mahatma Kote 28th Dec 2014 23:02

I've recently designed a GPS based vehicle locator/safety system for railway use. It uses 3G, Data Radio, voice radio, and satellite interchangeably to report to the control centre and receive alarms and alerts in return.

In my experience satellite is not really expensive. You can buy packages with a per message cost. I can't see how a per-message side-channel on existing aircraft satellite transponders would cost any serious amount at all - especially if it was only used for emergencies.

Asides from that, there is always the option of using normal VHF/UHF radio to squawk current location. Again, only in emergency, but sure to be recorded by any aircraft and ground-stations in range. It could be turned on for instance if the radio was set to the emergency frequency and would append a 'selcall' or DTMF burst containing GPS coordinates at the end of any message. Many land-mobile radios have this feature already.

slats11 28th Dec 2014 23:16

Primary V secondary radar
 
Without knowing the location and capability of primary radar in that region, it is difficult to know if it was even in range of primary radar.

Even if it was in range, it is pretty unlikely it was being tracked in real time by primary radar. At 0600 on a Sunday morning when there is apparently nothing out of the usual to cause the military to be on a higher state of alert? Who would have been looking?

Capn Bloggs 28th Dec 2014 23:24


Originally Posted by slats11
At 0600 on a Sunday morning when there is apparently nothing out of the usual to cause the military to be on a higher state of alert? Who would have been looking?

Radar tapes perhaps... :cool:

ekw 28th Dec 2014 23:28

In reference to the use of satellite to capture black box data debate:

Actually instead of just using satellite you could have the required data sent to a small onboard processor that performed the function of encrypting it. Then when the aircraft left the flight envelope it would be preprogrammed to pulse the data over multiple existing channels - Acars, transponder, VHF etc. The event could be triggered by altitude/speed readings. To cover inflight breakup the unit should be built in to one of the com relays with its own small power supply.


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