	2013			2012
Term loan with quarterly installments of principal and interest, with all remaining principal due in 2017. Interest rate at December 31, 2013, was 2.19%.	$	332,510			287,500
Borrowings under revolving credit facility with interest due not less than quarterly and all principal due in 2017. Interest rate at December 31, 2013, was 4.25%.		12,000			67,000
Notes payable with interest rates from 2.31% to 6.57%, due in monthly installments of principal and interest with balloon payments due at various dates in 2014 through 2024, collateralized by aircraft		156,841			36,934
Notes payable with variable interest rates due in monthly installments of principal and interest with all remaining principal due in 2015, collateralized by aircraft. Interest rate at December 31, 2013, was 4.00%.		1,276			2,211
Note payable with interest rate at 4.92%, due in monthly installments of principal and interest with all remaining principal due in 2018, collateralized by real estate		4,425			4,720
Notes payable with interest rates from 3.55% to 4.00%, due in monthly installments of principal and interest at various dates through 2019, collateralized by aircraft		6,861			3,206
Note payable with interest at 4.04%, due in semi-annual installments of principal and interest through 2019, collateralized by aircraft		2,540			2,907
		516,453			404,478
Less current installments		(39,415	)		(23,796	)
	$	477,038			380,682

In December 2013, the Company borrowed $60 million in the form of an additional term loan against its senior credit facility, primarily to fund the purchase of BHH. As of December 31, 2013, the Company’s senior credit facility consists of term loans with a balance of $332.5 million and $12 million outstanding against the $100 million revolving credit facility. Remaining available capacity on the revolving credit facility is $84.5 million and is reduced by three outstanding letters of credit totaling $3.5 million.

Borrowings under the credit facility are secured by substantially all of the Company’s accounts receivable, inventory, equipment, and general intangibles. Indebtedness under the credit facility has a first priority claim to the assets pledged to secure it. Quarterly principal payments began in 2013 as follows: 1.25% of total principal balance per quarter for quarters 1 – 8; 1.875% of total principal balance per quarter for quarters 9 – 16; and 2.5% of total principal balance per quarter for quarters 17 – 19. All remaining principal is due at the maturity date in December 2017 but can be prepaid at any time without penalty. Base Rate Loans (as defined in the Amended and Restated Revolving Credit, Term Loan and Security Agreement) bear interest at the greater of (i) prime or (ii) the federal funds rate plus 0.25% to 1.25%. The interest rate for LIBOR Rate Loans (as defined in the Amended and Restated Revolving Credit, Term Loan and Security Agreement) is generally the LIBOR rate plus 1.25% to 2.25%. As of December 31, 2013, the interest rate on the term loans was 2.19% and on the revolving credit facility was 4.25%.

Subject to certain conditions, the Company may borrow an additional $40 million under the senior credit facility. These additional borrowings may be in the form of term or revolving loans. The maturity date and the interest rate on the additional borrowings would be the same as all other outstanding borrowings under the senior credit facility.

Payment obligations under the credit facility accelerate upon the occurrence of defined events of default, including the following: failure to pay principal or interest or to perform covenants under the credit facility or other indebtedness with outstanding obligations exceeding $3 million; events of insolvency or bankruptcy; failure to timely discharge judgments of $750,000 or more; failure to maintain the first priority status of liens under the credit facility; suspension of material governmental permits; a material adverse effect with respect to the Company; and a change of control in the Company.

The credit facility contains various covenants that limit, among other things, the Company’s ability to create liens, declare future dividends, make loans and investments, make any material change to the nature of its business, enter into any transaction with affiliates other than on arms’ length terms, enter into a merger or consolidation, or sell assets. The Company is required to maintain certain financial ratios as defined in the credit facility and other notes.