A320 drivers please...
 

on the A320, what's the data source for the Mode C altitude response? One of the ADIRUs or a single encoding altimeter? I see the control panel allows switching between two XPDR unit, presumably they are each fed from different altitude sources?

So all you can say is the indicated altitude/level changed (same probably goes for airspeed).

Within a CB as well as the turbulence the pressure variations will affect readings on the pressure instruments.

Hence the advice to fly attitude and set power.

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.

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.

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!

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.

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.

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.

@Blacksheep

30Mb/s for realtime telemetry sounds a little over the top

Again, the idea is to open the real time telemetry automatically only for the aircraft in distress, out of course or non responsive.

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.

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.

Fine in principle, but implementation would be extremely difficult. How to you reliably define those last two events in reality, and rapidly enough?

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.

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.

It's called 'ADS', and already supported through satellite-based ACARS.

It does automatically, that means more faster and accurate than humans can do. Simple, based on exceeding of pre-estabilished parameters.

Hit by lightning, electrics including FADEC fried. Aircraft glides and ditches outside of the search area

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.

What do you mean? to use the other airplanes on route to transmit data similar to mobile telephony that uses poles ?

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.

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

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.

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)

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.

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.

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 !

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

- 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"


. Car's GPS do more than that.

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.

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...

And that's receive only :ugh:

You have convinced me to discontinue this discussion.

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.

out of your knowledge there are products that use 2 way satellite communication through Iridium network as emergency rescue beacon or anti theft

Agree!

@NuclearWeapon

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 ;)

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.

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.

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?

Radar tapes perhaps... :cool:

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.