Originally Posted by
lakedude
Alright this post spells it out perfectly:
http://www.pprune.org/8379267-post4191.html
The arc is in fact from the last ping.
That being the case there must be other arcs from the other earlier pings we are not being shown. If the plane was just a bit farther north (or south really) when they lost contact these other arc might be such that one of the N/S duplicates would be impossible. They must have pings from when they actually knew where the plane was. It is an unfortunate coincidence that the plane was so close in the N/S direction to the satellite when they lost track of it...
To add; why would the red lines on the arc at 40 degrees EXCLUDE the area between Vietnam-Indonesia, where the last verified contact with MH370 was made? Primary radar plots from that point on were of an "unidentified object".
The red lines an the north/south extremities of the 40 degree arc are based on maximum range and fuel loadings, but is it possible that the plane ditched in the sea at approx LKP, intact enough for SATCOM to keep pinging?
Not suggesting this is likely, however interested to know why that part of the 40 degree arc has been excluded.