“There was an FR post earlier today (which has since been pulled) in which an apparent FR aviation expert informed us that the ACARS sends data ONLY on significant events (gear-up, gear-down, achieving cruise) and NEVER on time. So the reports that it sent out data every half hour are wrong - it would not be expected to send out more data until gear-down (which didn’t happen).”
Actually he said that the ACARS sends reports every hour and that the engine monitoring system sends reports on gear-up, cruise and gear-down.
No, he didn't. Here is a quote from that post:
First,the ACARS. The system has been around since the 70s. It transmits engine data to Boeing/Rolls Royce servers through the Iridium satellite link. But here is the kicker. IT TRANSMITS ENGINE DATA REPORTS AT PRE-SPECIFIED EVENTS,NOT ON TIME. It will send a report at gear up, throttle back meaning cruise achieved (1:07am),and gear down.