Private equity firm Liberty Hall Capital Partners has purchased aircraft parts maker AIM Aerospace for $220 million. BlackRock Private Equity Partners and Northwestern Mutual Capital are also investing alongside Liberty Hall.

AIM, founded in 1988 and located in Renton, Washington, makes ducts and seat shells for 737, 777 and 787 airplanes. Some of its customers include Boeing Co. (NYSE: BA), Spirit AeroSystems Holdings Inc. (NYSE: SPR) and B/E Aeorspace Inc. (NASDAQ: BEAV).

“The commercial aerospace market continues to enjoy strong, long-term secular growth, driven by demand for next generation aircraft,” says Liberty Hall partner Rowan Taylor. “The growing demand for composites provides an opportunity for AIM to serve as the platform investment for Liberty Hall to build a fully-integrated, diversified composites supplier.”

Liberty Hall is a New York-based PE firm that focuses exclusively on the aerospace and defense industry. In addition to AIM, Liberty Hall also owns metal parts supplier Accurus Aerospace Corp., which has made three add-on deals since it was acquired by the firm in 2013 including: LaCroix Industries, McCann Machining and Precise Machining & Manufacturing.

PE firms are continuing to go after airplane part manufacturers as carriers look to upgrade their fleets. In 2015, Apollo Aviation Group (not affiliated with Apollo Global Management) raised a $833 million aerospace fund and Kidd & Co. and Centerfield Capital Partners-backed Imaginetics LLC is buying Azmark Aerosystems LLC. In January, Warren Buffett’s Berkshire Hathaway Inc. (NYSE: BRK.A) completed its $37 billion purchase of Precision Castparts. For more on the aerospace industry, see As Aircraft Industry Updates Planes, Parts Makers Will Bring in Buyers.

Lincoln International, Stephen Harwood along with Riddell Williams advised AIM. Schulte Roth & Zabel represented Liberty Hall. The PE firm received financing from Antares Capital, Citizens Bank, KeyBanc Capital Markets (NYSE: KEY) and Carlyle GMS Finance.