Our net debt to shareholders' equity ratio was 37.3% as of January 31, 2013, with net debt (total debt less cash and cash equivalents) of $235.8 million principally incurred to fund certain fiscal 2012 acquisitions and the payment of a one-time special and extraordinary cash dividend totaling $116.6 million in December 2012. We have no significant debt maturities until fiscal 2018.
As expected, global economic uncertainty and domestic governmental spending reductions were principal contributing factors to the nominal sales growth and lower operating income reported in the first quarter of fiscal 2013. As we look ahead for the remainder of fiscal 2013, we remain optimistic in the consensus outlook for the commercial airline industry and expect to see growth in airline capacity and maintenance spending in the back half of fiscal 2013. Additionally, we expect improving demand for certain products of our Electronic Technologies Group in the space, aerospace and medical industries.
Based on current economic visibility, we are increasing our estimates of full year fiscal 2013 year-over-year growth in net sales to 6% - 8% and growth in net income to 9% - 11%, up from our prior growth estimates of 5% - 7% in both net sales and net income. Additionally, we continue to estimate consolidated operating margins to approximate 18% for the full fiscal 2013 year. Approximately seventy five percent of this growth is expected to be organic which would represent organic growth of approximately 7% for the balance of fiscal year 2013. HEICO remains committed to acquiring profitable businesses at fair prices, and we are actively pursuing opportunities within both our segments. These estimates do not include the impact of any potential 2013 acquisitions."
Flight Support GroupEric A. Mendelson, HEICO's Co-President and President of HEICO's Flight Support Group, commented on the Flight Support Group's first quarter results stating, "Our Flight Support Group performed in line with management expectations and is positioned to take advantage of improving market conditions. Operating results for the first quarter of fiscal 2012 were a challenging comparable period to the first quarter of fiscal 2013 because the first quarter of fiscal 2012 was highlighted by 10% organic sales growth, an increase of 25% in operating income and a 1.5% improvement in operating margin.