By MickG0105
You may want to re-read. Some of your statements don’t make sense.
30-35 km is 16-19 NM from the 7th Arc. Using the BTO standard deviation for arc 7, the crash site can be up to 40 nautical miles from the seventh arc. That’s why they searched up to 40 NM from the arc at 38S.
It’s not 18:44UTC, but 0018:44 UTC. At that time I estimate it had drifted down to its max single engine service ceiling of ~ FL295. Left engine had failed at 2307:30 UTC (71 minutes and 14 seconds earlier) due to the left thrust lever remaining at the high thrust setting for 0.84M since TOPD (left autothrottle inop). The right thrust lever with the operative autothrottle reduced to a very low setting to reduce speed to 268KIAS at TOPD. Large thrust asymmetry at TOPD results in a larger fuel exhaustion time between the left and right engines.
Total fuel exhaustion is at 0018:44 UTC, 46 seconds prior to arc 7 at 0019:30 UTC.
Super, here's a colon - : - try placing that between your hour and minute values.
Regarding the BTO error, it is in the order of 30 μs or 9 kilometres. You are conflating the likely glide distance post fuel exhaustion as derived from the Boeing simulations - the figure used to determine likely distance from the 7th arc that the aircraft might impact the ocean and therefore search swathe - with the BTO error. Two markedly different things.
At 00:19:29 UTC the aircraft
must be within about 9 kilometres of the 7th arc - your scenario has the aircraft four times that distance away. That's a problem.