According to Factual Information, there was a 37 second gap between the disapperance of "Mode S" and "Rader position symbol", what may have caused this gap?
The Mode S symbol of MH370 dropped off from radar display at 1720:36 UTC [0120:36
MYT], and the last secondary radar position symbol of MH370 was recorded at 1721:13 UTC
[0121:13 MYT]