Originally Posted by RTD1
Do we know when the military primary radar BEGAN picking up MH370?
I'm curious how the v-shaped route from the time of last secondary contact to the time of last primary contact was drawn. Is there actual evidence to support it or is it just based on the Thais saying "we didn't pick it up so it couldn't have flown over Thai airspace"?
The Vietnamese have indicated that they saw the plane turn around but they didn't give any details as to whether this occurred before or after the transponder was turned off, but if we assume that it occurred after the transponder was turned off we will know that Vietnamese primary radar tracked the flight as early as 1:22 local time. The Thai government has stated that they first picked up the flight at 1:28 'flying in the direction opposite from the MH370 plane, 'back toward Kuala Lumpur' (paraphrased.) The Malaysians have remained vague and the Indonesians have left it up to the reader to read between the lines to know that they tracked the flight at all. (see my post above)
As to the Vee shaped flight path in the diagram:
I see no reason to think the flight went near Butterworth; the pilot had brought the plane down to low altitude to avoid (at least) Thai radar, and ground speed was suffering as a result; he (or she) would have wanted to clear Thai/Malaysian airspace as quickly as possible so I predict a turn towards MEKAR somewhere around 5°36'25.08"N 101° 6'29.92"E (or about 45nm ENE of Butterworth.)