if (defined $aircraft_id_1){
  open(INFILE_2,"<${file_2}") or die "Can't open ${file_2} : $!";
  while (my $line_2 = <INFILE_2>){
    chomp($line_2);
    my @Elements_2 = split(/;/, $line_2);
    my $aircraft_id_2 = shift @Elements_2;
    if ($aircraft_id_1 eq $aircraft_id_2){
  	print OUTFILE join(';',@Elements_2), "\n";
    }
  }
  close INFILE_2;
} else { print OUTFILE (";" x (40-$meter)), "\n" }