Speaking as a dumb pax, I’ve been appalled/astonished to learn from all this that comms/tracking systems can be simply ‘switched off’. So if the mod’s will permit:

1. Under what circumstances (terrorism aside) would these systems be switched off by crew?

2. Putting aside the who/why of the MH370disappearance, what do you pilots want or anticipate will happen with these systems in the future? Will they or should they be configured so that they can never be turned off?

From my angle, I’d feel a wee bit safer if I thought that my flight was always broadcasting its location.

FE Hoppy

And how much further could you go at ECON Cost Index 0 for the same fuel load?

If your speed was 0, indeed you're going nowhere, but for the purposes of establishing a search area, I think assuming the speed of the aircraft was 0 is irrelevant.

All anyone can do is:

Look at how much more than Flight Plan fuel was loaded.

Take the FOB (Fuel On Board) figure from the last ACARS position report or estimate it from the PLOG at the waypoint where the ATC handover took place if the ACARS didn't report it, amending for any extra uplift of fuel, pre-departure.

Establish Maximum & Minimum Range markers based on facts including potential crew instigated cruising Mach/IAS variation techniques (ECON CI '0', LRC, Mmo etc.) & 'best guessed' fuel on board for endurance from the last known position.

When new information comes to light such as the aircraft may have been 'Terrain Masking' it would probably add a much smaller 'theoretical' range than originally thought because of the increased fuel burn at low level, ergo reducing range.

Using 'Minimum Airspeed 0' will only keep you at the last KNOWN position. And it aint there.

Aviator1970

It won't work if it's turned off but it's turned on so they can locate the SIA which means...?

lack of pings
 

The lack of info on previous pings from MH370 might mean:

1 - the data is not available. Seems unlikely
2 - the data doesn't correlate with other known observations and is regarded as irrelevant.
3 - the data is not being released because it might compromise something happening behind the scenes.

Given that the aircraft tracked eastwards initially, perhaps the POR satellite picked up its signals, rather than IOR. Furthermore, if this happened during climb prior to ACARS becoming disabled, there would probably be some useful data to look at. The collective expertise of others on this forum might well hold the key to solving this puzzle, given the right information.

It will of course not. You can fly for 30 minutes, then crash. You can fly for 1 hour, then crash etc.

I am just an occasional visitor of this thread looking for any substantial development in this mysterious disappearance.

Can someone please explain to me the origin of the 'corridors'?

I understand that the red circle represents the distance between the airplane and the satellite at the time of the last 'ping'. I suppose there is another circle centered on the position of the aircraft at the last radar contact, and a radius equal to the distance flown in the time between the last radar contact and the last ping. So the last possible positions of the aircraft are the two intersections of these two circles or somewhere in between. Why would the airplane proceed from these points along the red circle?

@ DADDY-OH
 

If you use the minimum flight speed to define the nearest point on the arc you are neglecting the fact that the aircraft could fly in circle at the minimum flight speed rather than a straight line.

I know having spend far too many hours flying in circles in large aircraft.

Terrain masking? Couldn't a descent be in response to depressurization, or at least announced to pax as such if nefarious to keep up appearances?

A laptop with a $20 USB radio receiver can pick up and display ADS-B data no problems. No need to turn on any active systems.

Every device that draws power from the airplane's electrical system needs to be able to be switched off or at least needs to have circuit breaker which trips or can be manually pulled in case something in the device shorts. This CB trips ideally before a fire erupts. Fire and airplanes are a bad combination and have on far greater occasions led to tragedy than terrorism or auto-hijacks have.

If anything, we should be seriously reconsidering the hijack proof doors, as many have noted, once someone is in there who's crazy, nobody can get to them to stop them. At least in the days of the plastic toilet doors, there was an easy way in.

Airfields in Southern Indian Ocean
 

any list of old disused/abandoned airfields of any vintage in the southern Indian Ocean? I am sure its been discussed...

I agree, and I'm surprised no cellphone pips have shown up anywhere. I know that passengers are required to have their phones in "airplane mode", but I also know that you never get 100% compliance with that. So it would be reasonable to assume that at least some GSM phones would have been switched on, either in passengers' pockets or bags. I know I have left my phone on between SIN and FRA (by mistake) and have received "Welcome to xxxx" messages from one or two countries along the flight path.

That said, GSM jammers are quite cheap and easy to come by in parts of Asia...

In which case his TCAS theory is rubbish.

Can a laptop track accurately enough to allow an intercept? I doubt it as TCAS isn't that accurate and it does NOT show you direction of travel in any case.

Cargo
 

okay so the airline CEO is now saying that the plane's cargo contained mostly 3-4 tonnes of mangosteens that it was carrying to China. He also added, "no hazardous cargo" on board.

Valid point someone did about 25 pages back making the arcs look like a big "sausage)


Just looked back it is post#4521 on page 227 posted by PJM.

You're better off staying away.

However,
The there is no inference that the aircraft proceeded along the red line. The red line simply plots all the possible positions at the time of last ping.
The extremes of the line are based on range from last known position and I assume they are now wind corrected and take into account possible fuel remaining at time of last ping.

There is some confusion now over the gap in the middle as the explanation given at todays press briefing is what we would call "bobbins" in my part of the world.

It can track as accurately as the resolution of the ADS-B location inputs. All the laptop does is listen to the ADS-B broadcasts and display the location, elevation, and call-sign data sent in the broadcast.

I don't know if the same location data (GPS? and/or INS?) is used in TACAS.

I would guess the location and elevation data is at least as good as GPS data - i.e. a couple of tens of metres laterally and twice that vertically.

Had the waypoint been inserted on the ground, before activating the flight plan, admittedly a check of the whole route would be visible to the crew, but would an ACARS report be triggered then ?

As I posted earlier, I have little doubt that after AF 447 and now MH370 there is a need for a complete re-think on Flight Data Recorders for long range aircraft, with ETOPS sectors, becoming ever longer.

My thoughts on real time FDR transmission through ACARS or other SATCOM is not entirely new but I see the major consideration seems to be cost even though the technology exists. Whilst that cost issue MAY be the case if there was continuous data streaming can any electronics or satcom engineers explain if the technology exists to make a burst of compressed data, lasting only a fraction of a second , say every 30 seconds. Data to include basic flight data, alt. airspeed, hdg, and GPS position. A 30 second interval could at least fix the aircraft to within 5 miles or so at Mach.8. AND even with basic data give an idea of the problem and greatly assist in the recovery of the full FDR and CVR.

A number of unsolved accidents led to the introoduction of FDRs and CVRs (and eventually, I guess, cockpit video recorders) so I have little doubt that, after the AF and MH problems, we WILL get this live data sooner or later.

Seat 32F
I think the data is there, its just that Boeing dont look at it