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Air Asia Indonesia Lost Contact from Surabaya to Singapore

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Air Asia Indonesia Lost Contact from Surabaya to Singapore

Old 28th Dec 2014, 19:12
  #201 (permalink)  
 
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Once again, we rely on outdated technology. No ELT transmissions received. This will only increase the pressure for industry wide deployment of REAL TIME FLIGHT DATA TELEMETRY.
And not before time.
Wouldn't matter. We still need reasonably intelligent PEOPLE to make reasonable decisions in a TIMELY manner.

Indonesia ATC lost radar and radio contact at 6:17, ADS contact at 6:18, and didn't call out an alert until 7:08. The VERY SIMPLE answer is that they should have sounded an alert as soon as contact was lost, so any of those military facilities, Coast Guard, merchant ships, and anyone else in the area would have been immediately alerted to a potential problem. If they regained contact a few minutes later, they could cancel the alert.

If the military radar operators don't know there's a problem, there's no reason for them to closely track EVERY airplane in their airspace. If other facilities & ships don't know there's a problem, there's no reason to post more watches or divert toward the problem area.
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Old 28th Dec 2014, 19:50
  #202 (permalink)  
 
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fireflybob is right

maintain constant pitch

maintain constant power


take whatever altitude or speed you get unless you are

1. sure you are stalling

2. running out of altitude and ground contact imminent.



so many questions...oon th e bus you can imagine both pilots hitting the stick and doubling or fighting over who is controlling.

oh well. God Bless them all


I do say that if all electric power is lost the ELT should be triggered. Also the ELT should be set with a timer to start transmitting at fuel exhaustion minus 10 mins.
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Old 28th Dec 2014, 19:52
  #203 (permalink)  
 
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I once hit a "dry" cell in the Caribbean in a 757 at FL350. It was night time...radar was on max manual gain tilted down -2, nothing ahead or in immediate vicinity, some stuff on either side about 80 miles abeam. Suddenly flew into a cell that caused severe turbulence for 10 seconds, over speed, and +/-500ft. Once out of it immediately ascertained everyone was ok and notified atc. Not 30 seconds later Speedbird (BA) 747 hit the same type of stuff well off to our right. There were dry cells all over the Caribbean that night. They do not show up on radar no matter how much gain (sensitivity) you have it on: not enough moisture to show on radar but plenty of punch!
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Old 28th Dec 2014, 20:16
  #204 (permalink)  
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The radio bands allocated to aviation are very limited and are being constantly eroded at every International bandwidth allocation meeting. Some years ago we were forced to reduce our VHF Communications to 8.33 KHz channel spacing to enable us to have enough available VHF frequencies. That is not a misprint - radio channel separation is about a third of the audio bandwidth of a decent Hi-Fi system. Imagine how tricky it is to prevent cross channel interference in such a tight channel space - the audio modulation is reduced to around 6.7 kHz! Meanwhile, global telecomms companies are after even more of the "under-utilised" frequency bands allocated to aviation.

All these people proposing real-time data telemetry of aircraft really have no comprehension of the technical difficulties involved in airborne communications. Bandwidth is limited and allocation is a regular bun-fight with everyone wanting to earn profits from grabbing a share. We already lost one entire band to cable television, for broadcasting Pap to the mass market. The frequency band currently used for Mode S/TCAS is being demanded for commercial use by telecomms companies.

Real time telemetry would involve something like a constant stream of 30 Mbs for each of possibly 400 aircraft in a ground footprint on the channel in use. Where do we get the bandwidth for that? Propose such a thing at the next international radio band allocation meeting and you'll be laughed out of the room. It's hard enough holding on to what we've got.
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Old 28th Dec 2014, 20:20
  #205 (permalink)  
 
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In a crisis like this, the data is needed very rapidly indeed. Had that been available, fast jets could have been dispatched to the GPS location to survey, and shortly after, assistance dropped as necessary, hopefully long before nightfall.
These days the airplanes are highly automated. History of LOC accidents and incidents shows that an FBW aircraft can accouter a panoply of flight laws and an endless stream of ECAM messages that can overwhelm any crew, as happened for an A380 over Singapore. Luckily, in A380 case, in addition to the normal crew of Captain, First and Second Officer, there were two additional check captains, all together did a great job in saving the plane.

An automated emergency system not only will alert the nearest rescue team in real time but it would open the possibility of streaming live the aircraft data to a very specialized team on duty, on a ground base station of experienced pilots and engineers . They will grasp the situation and work in real time with crew in distress given more chances of positive outcome.
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Old 28th Dec 2014, 20:21
  #206 (permalink)  
 
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Where are you going to get a broadband connection in the middle of the Indian Ocean if not from a satellite?
Without commenting on the overall feasibility of the idea, you would not need broadband for such a system. Sending a simple message containing data such as flight id, current lat/long, altitude, heading and speed would not need much bandwidth at all. Iridium's "short block data" service is one example of a globally available capability.

It's too simplistic to say that's all you'd need. But the data connectivity itself is not the show-stopper.
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Old 28th Dec 2014, 20:26
  #207 (permalink)  
 
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@Blacksheep

30Mb/s for realtime telemetry sounds a little over the top
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Old 28th Dec 2014, 20:39
  #208 (permalink)  
 
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Real time telemetry would involve something like a constant stream of 30 Mbs for each of possibly 400 aircraft in a ground footprint on the channel in use.
Again, the idea is to open the real time telemetry automatically only for the aircraft in distress, out of course or non responsive.
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Old 28th Dec 2014, 20:40
  #209 (permalink)  
 
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commsbloke says:
"30Mb/s for realtime telemetry sounds a little over the top".

I tend to agree. All the data that is absolutely necessary is callsign, GPS location and maybe some sort of status flag. A handful of bytes. More is desirable, certainly but let us distinguish between needing and wanting.

I think some people hate this idea for reasons of their own. One day, it might save their bacon.
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Old 28th Dec 2014, 20:44
  #210 (permalink)  
 
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30Mb/s for realtime telemetry sounds a little over the top
It is over the top.
But the principle is sound, that continuous transmission of all FDR data from commercial aircraft would far exceed available satellite capacity. And extending that capacity to the extent required would be extremely expensive. This was discussed at great length in the FH370 threads, and little has changed since then.

Simple position reporting on a continuous basis _is_ feasible, however it doesn't seem that this would provide much additional evidence in the present case since the aircraft was in primary radar coverage when lost.
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Old 28th Dec 2014, 20:48
  #211 (permalink)  
 
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Again, the idea is to open the real time telemetry automatically only for the aircraft in distress, out of course or non responsive.
Fine in principle, but implementation would be extremely difficult. How to you reliably define those last two events in reality, and rapidly enough?
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Old 28th Dec 2014, 20:52
  #212 (permalink)  
 
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Originally Posted by henra View Post
Are you sure your Maths is correct?
The Chance for the second Event being the same Country is 1/150 (like for any other Country as well). And for the third Event it is again 1/150th.
So even after the first risk materialised with a first incident, the risk for a second one would be 1/150th and a third one 1/22500.
With 1,5 per year you will have to wait for 15000 Years statistically for such a triple event.
Right. That's assuming that accidents occur in all countries with equal probabilities.

However, Indonesia has 250 million people and proportionally more aircraft (and, therefore, incidents) than, say, Nicaragua or Angola. (And it is much more sparse geographically: Nicaragua, contiguous and 500 x 500 km across, could live without airlines altogether - in fact, its airlines don't even own any passenger aircraft with capacity larger than 60. Indonesia is 5000 km across and consists of lots of islands, it can't function without aircraft.)

Indonesia and Malaysia taken together operate 1 out of every 40 777's, 1 out of 30 A320's and 1 out of every 12 737's in the world.
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Old 28th Dec 2014, 20:52
  #213 (permalink)  
 
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As a pilot with some engineering background I want to suggest a solution to this problem of locating aircraft after a crash. The fms knows where the aircraft is at any point in time in terms of longtitude and latitude. This changes rapidly during flight I know there's a page on the fms in my previous aircraft for getting this information. Upon impact greater than a particular force(g). This will prevent it being activated during severe thunderstorm. 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. This will continue for about twelve hours. Another aircraft along that route can pick up these details and pass it on. Every point on the ocean surface has a postion in lat and long coordinates.

The technology to do this is out there, they simply need to use it. My junior brother has a $300 phone that figured out without any input after some weeks where he worked and on what days as this was regular to a tee. He started getting a text everyday at five minutes before 9am that it was time to start driving to work. On Thursdays and Fridays that he was always off he never gets a text.

These aircrafts costs tens of millions of dollars and they a really telling us they cant find them after a crash. Iphones and Samsung phone tell you which city or street your friend is calling from! Any input or suggestion will be appreciated.
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Old 28th Dec 2014, 20:54
  #214 (permalink)  
 
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Originally Posted by ams6110 View Post
Without commenting on the overall feasibility of the idea, you would not need broadband for such a system. Sending a simple message containing data such as flight id, current lat/long, altitude, heading and speed would not need much bandwidth at all.
It's called 'ADS', and already supported through satellite-based ACARS.
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Old 28th Dec 2014, 21:03
  #215 (permalink)  
 
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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.
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Old 28th Dec 2014, 21:10
  #216 (permalink)  
 
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Hit by lightning, electrics including FADEC fried. Aircraft glides and ditches outside of the search area
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Old 28th Dec 2014, 21:10
  #217 (permalink)  
 
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The discussions on probabilities here are not all that meaningful. When you look at very rare events you don't have enough data to form a conclusion. This could just as easily be a random cluster than will never happen again, the country variable having no actual significance.
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Old 28th Dec 2014, 21:18
  #218 (permalink)  
 
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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. This will continue for about twelve hours. Another aircraft along that route can pick up these details and pass it on.
What do you mean? to use the other airplanes on route to transmit data similar to mobile telephony that uses poles ?
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Old 28th Dec 2014, 21:28
  #219 (permalink)  
 
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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 bullshit 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.
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Old 28th Dec 2014, 21:28
  #220 (permalink)  
 
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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.



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