robinbowes,
First a comment on style - you do not need to repeat the use of my if all the variables in the list will be new lexicals. 
my ($one, $two, $three) = qw(1 2 3); # works just fine

[download]
As far as using a datastructure, a hash makes the most sense since trying to remember which array index corresponds to which variable is a PITA. This will also allow you to create complex data structures (AoH, HoH, etc) later if you need to. 
#!/usr/bin/perl -w
use strict;

my $buffer;  # Defined elsewhere
my %hash;

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

@hash{@keys} = unpack ( "B16 n2 A4 A8 A2 A A A3 C2" }, $buffer);

print $hash{mode3};

[download]
There are two more things to point out. The first is that it appears you have more variables than the unpack will return - which means undef values. The second is to understand auto-vivication when using hash slices.

Cheers - L~R

In reply to Re: Data structure for this... by Limbic~Region
in thread Data structure for this... by robinbowes

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.