AAIB Doppler data
From the AAIB data there were 13 transmissions that were analyzed (did not include last "partial").
Four of those thirteen were prior to 1710 (UTC) and presumably were expected transmissions.
From that time forward the (approximate) intervals between transmissions are:
78 minutes,
2 minutes,
2 minutes,
70 minutes
60 minutes
60 minutes
60 minutes
31 minutes
followed by the "partial" 8 minutes later.
Can anything be deduced from the inconsistant time intervals, particularily contacts 6,7,8 (at approximately 18:25, 18:28 and 18:30 (UTC)?