Helicopter leasing company Milestone Aviation Group signaled its intention to offer stock to the public–an initial public offering (IPO)–yesterday in a filing with the U.S. Securities and Exchange Commission. No date for the IPO has been set, nor has any valuation been placed on shares to be offered. Milestone was founded by former NetJets CEO and founder Richard Santulli in 2010 with an initial capitalization of $500 million. The company’s current fleet is valued at $2.2 billion and it has more than 145 helicopters on order worth $3.4 billion.