No one can accuse Kestrel Aircraft of lacking ambition. The company unveiled a revised cabin mock-up of its in-development, all-composite single-engine turboprop over the summer. It features an executive interior nearly as opulent as what would be found in a new $40 million corporate jet, resplendent with high-gloss wood veneers, upscale leathers, a wide aisle and oversized oval cabin windows reminiscent of a Gulfstream. Basically, everything a traditional turboprop is not. All this in an airplane that is expected to hit the market with a price tag around $3 million.

The interior design is largely the brainchild of Kestrel industrial designer Ray Mattison, who cut his teeth in the business working at Cirrus Design on the SF50 Vision jet. Mattison said the executive layout, with a spacious club-four passenger grouping aft of the cockpit, is just one of nine interiors Kestrel is developing for the aircraft. The others will accommodate missions as diverse as medevac, cargo and a high-density configuration for eight passengers. “It’s a very flexible cabin,” said Mattison, and “we hope that one cabin design will accommodate different seating layouts.” The cabin will feature a seat tracking system that will facilitate quick changes between configurations.

Mattison and his team aimed to create a spacious cabin, both in actuality and appearance, while striving to minimize weight. One immediate concession: the executive passenger seats will not swivel. All the ventilation and wiring is located in the cabin sidewalls, as opposed to the ceiling, maximizing headroom. “We have a wide aisle and good headroom clearance,” Mattison said. “We’re not too terribly far along in the materials qualification process but the design is left open to interpretation. If you look into the cabin you have fields of color, large areas that are purposefully decorated. We are covering the cabin walls in leather and cloth so the design is purposely made to be customizable within reason.”

On the mock-up, Mattison stressed the use of “honest” materials. “I really dislike fake materials, such as carbon fiber that is not structural,” said Mattison. The mock-up features fields of dark brown with cool contrast colors, upscale Alcantara (a composite leather replacement), leathers, and exotic African woods. The split sidewall promotes a diversity of colors and accents that creates a sculptured appearance. Carmel leather and Alcantara is used on the mockup sidewalls. “It is very sculptural and there are purposeful light catches within the sculpture,” he said. “We sculpted it with a flare and a return and spent a lot of time working on exactly how these surfaces and panels influence each other. It has a taut surface design layer to it that makes a nice light catcher and is pleasing to the eye. This is going to be fantastic.”

Decisions on the window treatments, cabin management system (CMS) and the environmental controls (ECS) remain to be made, but the ECS will be dual-zone (cabin and cockpit) and will be “very large,” said Mattison, facilitating adequate airflow and rapid heating and cooling.

The cockpit features sidestick controls, a low, contoured instrument panel with large, flat-panel avionics displays and a wrap-around windshield allowing views of both wingtips.

“The loft–the outside aerodynamics–are basically done. That is a huge part of it and we have done a lot of detail design,” said Kestrel CEO Alan Klapmeier, who is continuing to build his team and raise capital. Kestrel recently completed a successful new round of fundraising and employs 85, mostly from its new offices in Superior, Wis. “You want people with a certain amount of experience, but not too much, so they are open-minded.”

Klapmeier said some critical decisions–such as which composite material to use–remain to be made. “The design stuff feels good. Most of the answers are coming in where we expected. The airplane is coming in a little heavier than we want so we have a lot of people working on weight issues. For example, the Honeywell engine comes with two big batteries so we are experimenting with one lithium-ion battery. If we go that path, we get rid of 75 pounds. You have lots of these little issues on the critical path. We’ve done a lot of risk reduction,” Klapmeier said.

Kestrel (Booth No. 5585) continues to acquire capital and has begun building the tooling required to manufacture the conforming prototype aircraft. “The financing pieces will come into play at various times. We know enough about the process, we have a very experienced team, we know the product, we know what the customer looks like and we are very comfortable with the business proposition. We will raise the money we need. In general, we feel really good about it,” Klapmeier concluded.