Bell Helicopter is laying off 315 more employees and suspending all new external hiring, it announced on Tuesday, citing declining production of the V-22 military tiltrotor and a softer commercial helicopter market. Bell CEO John Garrison said the move is necessary in the face of “significantly lower V-22 production, the reduced demand across the global commercial rotorcraft industry and our customers’ continued demand for cost concessions.”

The V-22 is Bell's largest program, and deliveries this year are expected to decline to 21 from 37 last year. Most of the new  layoffs will be confined to the Fort Worth, Texas area—where Bell continues to employ 4,750—and come from the ranks of both management and non-management. Bell has announced several rounds of layoffs over the last year.