Flash, sadly the crew are tangible whereas person or persons unknown are not.

In the case of the former it would be negligent of the authorities not to consider one or both to be culpable.

As they are also re-examining the passenger list, and I would hope the cabin crew, they may have additional persons to consider in greater detail.

FE Hoppy
 

Will it?

In fact I will modify my previous post to say that the arcs will not even give an average speed of the aircraft unless it is flying to or from the satellite on a radial.

In themselves, the previous pings tell us virtually nothing.

It's hard to imagine a NON CREW to have the sophisticated knowledge of B777 systems and flying skills to operate with such cunning precision as such.

the outer most points of the final arc are based on long range cruise from last radar position.

That creates range at time points outwards from last known radar position. If any range from ping arc falls inside the equivalent range from last known position ring it reduces the range from that time.

Also if any range from ping arc falls completely outside the range from last known position ring then the aircraft was flying faster than long range cruise and this also reduces the further maximum range.

and the same applies for maximum speed calculations and minimum speed calculations.

Flight sim nonsense
 

Maybe the Capt had practiced approaches to Male, DG, and other locations because as a keen flight sim enthusiast and 15,000 HR commander who presumably often operated over the Indian Ocean he wanted to see what the approach patterns were for airfields that he might one day need to divert to?

All the airfields that people are getting excited about are listed alternates for IOR ETOPS. Chugging around Africa in a C-182 I often check out the approaches and obstacles on possible alternates even if I have no intention of landing at them. It's common sense, not conspiracy.

Where does this info come from?

NOT TRUE.

if you flew at 90deg to the rings the 1hr period would carry you the maximum distance from the previous ring. If you flew at a true tangent to the previous ring the distance from it to the next ring would be the minimum (same distance flown but less distance out from previous ring.

If that variance was constant each hour it indicates aircraft on a consistent course but no indication to what that course would be, I did state in the original post way back assuming a constant speed ( as that is what the seem to be assuming.

However to me a consistent course equals south

Going back to this lovely map with the arcs and the concentric range circles (http://tmfassociates.com/blog/wp-con...H370_Mar17.jpg) where on each arc would the aircraft had reached if it just continued flying at its last known speed?

Would the point of intersection of the southern arc and a circle representing range at last known speed be around the same area the Australians and Kiwis are currently searching?

Either that, or it's simply the case that up to now nobody asked the only people (Inmarsat) who were in a position to answer the question.

But I'm struggling to see what would be the point of the satellite keeping a log of historical ping acknowledgments, so overwriting old data in a circular buffer makes perfect sense.

Even if the previous pings had been available, that would only have provided a set of concentric arcs in a chronological sequence. There would be an infinite number of hypothetical tracks that could intersect the series of arcs.

Most likely yes but not necessarily.

There are at least two possibilities that would tell us something:

1) The difference in distance to the aircraft between consecutive pings is close to the max distance the aircraft could have flown in the time between pings. This would mean the aircraft was flying either directly away or directly towards the satellite.

2) All or several pings measured the same distance to the aircraft. This would mean the aircraft was either stationary or flying exactly along the equi-distant radius to the satellite.

If the a/c was in HDG mode it would have followed a loxodrome. Each heading gives a different loxodrom. Simply speaking each of these loxodromes can be seen as curves (not circle segments!) around the point where IOR is in the Zenith. Loxodromes with higher curvature will produce higher differences in ping times. Thus you can derive the heading of the loxodrome.

In reality the calculations to fit the loxodromes to the ping and wind data will be quite complicated. Something like this must have been done to get to the courses which are depicted in the press kid from AMSA.

thanks for the correction.

AIS data is notoriously unreliable. The AIS system is meant to prevent collisions between ships, and for that purpose it works well. There are a number of large multinational firms as well as government that subscribe to the AIS satellite and terrestrial coverage. There are two constellations of civilian satellites I am aware of that can pick up the AIS transmissions; there are probably more that are military/intelligence.

I worked extensively with a large AIS dataset for several years. We often times would see vessels with incorrect IMO numbers, duplicate vessels (in different positions) or even vessels located in the middle of Africa or Siberia. Part of this is due to how the transmissions arrive at the satellite; the transmissions can 'collide' and the satellite gets confused as to the true transmissions that are arriving simultaneously. This means that using the AIS data requires several layers of data cleansing.

Speed was notoriously unreliable on AIS and does not correspond with distance traveled for a vessel track. We would sometimes see vessels traveling at an indicated 100kt; obviously impossible. We would ignore speed and compute a vector based on the last two positions and elapsed time. Destination is also unreliable on AIS as it is entered by the crew and often times they will forget to change it after leaving a port.

Finally, AIS transmitters are deliberately turned off around the horn of Africa, mainly to avoid detection by pirates.

Spoofing an AIS signal would be trivial for anyone as well who wanted some type of 'civilian' cover.

Not quite. Repeated pings on the same circle would strongly suggest the aircraft on the ground and still transmitting. Also, the location of earlier pings would give dual locations (north and south) and times for the countries overflown to do a very careful search of the radar and/or confirm possible visual sightings.

Crew
 

To all who do not want to believe that the crew might be involved (and I can totally understand why, they are your peers): There are 200+ people on board, two of them we know are trained to fly a T7 - who would be your first suspect (albeit shouldn't be your only one)?

The ship tracking websites work in the same way as the aircraft tracking ones, i.e. using volunteers. But it seems unlikely that there are any volunteers in the middle of the Indian Ocean so those tracks must have been uploaded by a ship via satellite.

There are sometimes errors in the AIS data and some aircraft and helicopters, particularly SAR ones, transmit AIS. These tend to only have a MMSI, i.e. no IMO.

I have doubt's about the crew, I really can't see anyone climbing 2000ft above max alt especially at the weight they were likely to be at. I suspect that the aircraft climbed at full power ran out of speed then dropped down to FL295 if that's what it did.

ETOPS alternate airports in the Indian ocean? A current check of MH System Timetable destinations and routes shows no service and no routings across the southern Indian ocean. MH does not operate in the southern Indian ocean south of Male. :ooh:

Here's a report of an AIS spoofing demo:

The Guys Who Can Make Oil Tankers Disappear, Virtually - ABC News

VHF ACARS (and possibly CPDLC) is similarly vulnerable from what I see.

How confident are the authorities of the radar fix at 02:15 which has MH370 heading West? For me this fix and the two current search areas just don't match up. in my view either the 02:15 fix is wrong or they are searching in the wrong area?