US start-up Icon Aircraft has raised $60 million in a fourth and final round of equity fund-raising for its A5 amphibian.

The capital will be used to support "regulatory compliance", ramp up production of the special light sport aircraft (S-LSA) and fund research and development of future products.

Icon says the investors are from North America, Europe and Asia. The participation of Icon's Asian investor - a multibillion-dollar conglomerate that is well established in the Chinese general aviation industry - will enable the Los Angeles-based developer "to capitalise on the continent's rapidly growing GA industry," says Icon founder and chief executive Kirk Hawkins.

Meanwhile, Icon is still awaiting a conclusive response from the US Federal Aviation Administration to its request for an exemption to the LSA weight limits.

Icon first applied on 7 May 2012 to be exempted from the 649kg (1,430lb) weight limit for a S-LSA because the A5 uses a spin-resistant airframe. It is a feature intended to improve safety but means the A5 will exceed the FAA's weight limit under the S-LSA category without the exemption, Icon says.

But in a 2 May letter to Icon, the FAA's manager of the small airplane directorate in Kansas City, Missouri, said approval would be "precedent-setting" and, as a result, the agency needs more time and information to process the company's request.

The FAA is compelled by the regulatory statute to consider weight exemptions when they have the potential to improve safety, but in the past agency officials have been reluctant to approve such applications.

In September 2012, the FAA rejected Bell Helicopter's request for a weight exemption for the Bell 429 medium-twin helicopter, despite a previous approval by Transport Canada.

In its rejection letter, the FAA reasoned that exempting the 429 would put its rivals at a competitive disadvantage for remaining within the weight limits.

Approving a similar exemption for the A5 could provoke similar questions. Independent Aircraft's SeaDragon, for example, was designed to meet the S-LSA weight limit for which the A5 is seeking an exemption.

"This has been a longer and more challenging journey than even we had anticipated," says Hawkins. "That said, Icon is now in a great place." The company has secured about 1,000 orders for the two-seat aircraft to date.

Source: Flight International