The maker of an experimental zeppelin at a Tustin blimp hangar is seeking $60 million from investors to finance a future fleet of cargo-carrying airships.

Aeroscraft Corp. of Montebello announced a “convertible preferred stock” offering Monday, seeking to sell 1 million shares at $60 a share to institutional and high-net-worth investors, a company statement said.

The blimp manufacturer, which recently changed its name from Worldwide Aeros Corp., plans to build 22 new airships by 2020 or 2021, one version capable of carrying 66 tons of freight, the other with a 250-ton capacity.

The private stock offering is available only to banks, partnerships, corporations, nonprofits and trusts, or to individuals with a net worth exceeding $1 million who earn at least $200,000 a year.

The stock offering is being handled by Drexel Hamilton, a Wall Street firm owned and operated by disabled veterans.

A prototype airship that features a unique ballast system allowing for takeoffs and landings virtually anywhere had been in test flights at the former Tustin Marine Corps air station. Work on the 254-foot-long, blimp-like ship halted in October, however, after a partial roof collapse shut down the north blimp hangar.

Repairs are under way, and Aeroscraft officials hope to gain access to the hangar in the next two weeks to assess damage to the prototype from the collapse, Aeroscraft spokesman John Kiehle said.

Despite the setback, the firm continues to report progress, citing partnership talks with about six other companies to assist in the airship’s development, Kiehle said.

In March, Aeroscraft announced an memorandum of understanding with Amur Minerals Corp. to explore flying equipment to the mining firm’s Siberian operation.

The Aeroscraft airship uses air as ballast, the way a submarine uses water. It takes on air when it wants to descend and fills its hull with lighter-than-air helium to take off or gain altitude. Company officials say the ballast system makes it possible to fly cargo into remote areas without ground landing facilities.

Once Aeroscraft officials gain access to the Tustin north blimp hangar next month, they plan to move their prototype to the former air base’s southern twin, Kiehle said.

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