EMPLOYEE BENEFIT PLANS

Pension Plans

The following table provides a detail of the components of net periodic pension cost (in thousands):



	Three Months Ended September 30,						Six Months Ended September 30,
	2017			2016			2017			2016
Service cost for benefits earned during the period	$	157		$	1,794		$	311		$	3,754
Interest cost on pension benefit obligation	3,838			4,377			7,589			9,158
Expected return on assets	(5,432		)	(5,920		)	(10,741		)	(12,391		)
Amortization of unrecognized losses	1,819			1,793			3,597			3,755
Net periodic pension cost	$	382		$	2,044		$	756		$	4,276

The current estimates of our cash contributions to our defined benefit pension plans to be paid in fiscal year 2018 are $15.3 million, of which $8.2 million was paid during the six months ended September 30, 2017. The weighted-average expected long-term rate of return on assets for our U.K. pension plans as of March 31, 2017 was 4.4%.

Incentive Compensation

Stock-based awards are currently made under the Bristow Group Inc. 2007 Long-Term Incentive Plan (the “2007 Plan”). A maximum of 10,646,729 shares of common stock, par value $0.01 per share (“Common Stock”), are reserved. Awards granted under the 2007 Plan may be in the form of stock options, stock appreciation rights, shares of restricted stock, other stock-based awards (payable in cash or Common Stock) or performance awards, or any combination thereof, and may be made to outside directors, employees or consultants. As of September 30, 2017, 2,309,469 shares remained available for grant under the 2007 Plan.

We have a number of other incentive and stock option plans which are described in Note 9 to our fiscal year 2017 Financial Statements.

Total stock-based compensation expense, which includes stock options and restricted stock, totaled $2.4 million and $2.0 million for the three months ended September 30, 2017 and 2016, respectively, and $6.5 million and $6.2 million for the six months ended September 30, 2017 and 2016. Stock-based compensation expense has been allocated to our various regions.

During the six months ended September 30, 2017, we awarded 600,618 shares of restricted stock at an average grant date fair value of $7.15 per share. Also during the six months ended September 30, 2017, 1,256,043 stock options were granted. The following table shows the assumptions used to compute the stock-based compensation expense for stock options granted during the six months ended September 30, 2017:



Risk free interest rate	1.78	%
Expected life (years)	5
Volatility	56.1	%
Dividend yield	3.98	%
Weighted average exercise price of options granted	$7.03 per option
Weighted average grant-date fair value of options granted	$2.53 per option

During June 2017, we awarded certain members of management phantom restricted stock which will be paid out in cash after three years. We account for these awards as liability awards. As of September 30, 2017, we had $0.4 million included in other liabilities and deferred credits on our condensed consolidated balance sheet and recognized $0.4 million in general and administrative expense on our condensed consolidated statement of operations during the six months ended September 30, 2017 related to these awards.

Performance cash awards granted in June 2017 have two components. One half of each performance cash award will vest and pay out in cash three years after the date of grant at varying levels depending on our performance in Total Shareholder Return against a peer group of companies. The other half of each performance cash award will be earned based on absolute performance in respect of improved average adjusted earnings per share for the Company over the three-year performance period beginning on April 1, 2017. Performance cash awards granted in June 2015 and June 2016 vest and pay out in cash three years after the date of grant at varying levels depending on our performance in Total Shareholder Return against a peer group of companies. These awards were designed to tie a significant portion of total compensation to performance. One of the effects of this type of compensation is that it requires liability accounting which can result in volatility in earnings. The liability recorded for these awards as of September 30 and March 31, 2017 was $7.7 million and $14.2 million, respectively, and represents an accrual based on the fair value of the awards on those dates. The decrease in the liability during the six months ended September 30, 2017 resulted from the payout in June 2017 of the awards granted in June 2014, partially offset by the value of the new awards granted in June 2017. Any changes in fair value of the awards in future quarters will increase or decrease the liability and impact results in those periods. The effect, either positive or negative, on future period earnings can vary based on factors including changes in our stock price or the stock prices of the peer group companies, as well as changes in other market and company-specific assumptions that are factored into the calculation of fair value of the performance cash awards.

Compensation expense related to the performance cash awards recorded during the three months ended September 30, 2017 and 2016 was $4.4 million and $3.6 million, respectively, and during the six months ended September 30, 2017 and 2016 was $1.4 million and $2.5 million, respectively.