You could use a hash like this:

my @keys = qw(flags x y mode3 callsign route spare1 spare2 flight_leve
+l
              terminator chksum_packet);

my %record;

@record{@keys} = unpack("B16 n2 A4 A8 A2 A A A3 C2", $buffer);
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Just use $record{flags} instead of $flags etc.