Missing Flights

[Garry Emanuel]

Have been wondering why some flights/aircraft don't show up on ACARS or have incorrect details.

Have been tracking a few flights in and out of Sydney over the past week and notice that quite often QF A380's don't appear (QF127/128 in particular) and QF A330's have incorrect data (QF81/82 still shows as Singapore/Adelaide and Darwin/Singapore whilst QF23/24 shows as Unknown and Bangkok/Sydney).

Not very savvy about how the ACARS data is held on planes and sent to the receivers.

Thanks in advance.