3% off $100k is paid out over the year, so 2011-2102 =$3000 and 2012-2013 =$3000, total $6000 not $9000. You have included 2013-14 which hasn't happened yet.
$100K. 3%. at 1 Jan 2011.
1 Jan 2011 to 1 Jan 2012 = $3K
1 Jan 2012 to 1 Jan 2013 = $3K
= $6K backpay on first 3%
THEN 3% at 1 Jan 2012
1 Jan 2012 to 1 Jan 2013 = $3K on second 3% increase.
Total, not accounting for compounding effect = $9K.
What was determined, less compounding effect:
4.5% at 1 Jan 2012
Total backpay 1 Jan 2011 to 1 Jan 2013 = $4.5K
The simple addition (ie non-compounding) wage increase from 1 Jan 2011 to 1 Jan 2014 would be 12% under what was asked by AIPA (ie 3% from 1 Jan 2011), what was achieved was 10.5%.
Note that the last pay increase under the previous EBA was 3% at 1 Jul 2010, so another 3% 6 months later was not a realistic expectation. QF wanted no back pay at all. Overall, I don't think what was awarded was unreasonable. Neither party has been rewarded for not coming to a timely agreement.
The big winner (if Qantas ever hires again) is no B scale for new entrants.