Details Emerge in Fatal Icon Crash

The aviation world was rocked Monday when acclaimed aeronautical engineer Jon Karkow and fellow Icon Aircraft employee Cagri Sever died in a crash of an Icon A5 amphibious plane on the shores of Lake Berryessa in Napa, California. The A5, which has received FAA certification but not yet reached market, has been one of the most hotly anticipated aircraft designs in recent years, with its sleek appearance and advanced safety features key selling points.

According to NTSB spokesman Peter Knudson, the flight departed from Nut Tree Airport in Vacaville. Karkow, Icon’s lead test pilot as well a designer, was giving an introductory flight to the newly-hired Sever. A boater on the lake saw the plane flying 30 to 50 feet above the water. It passed into a cove, and the witness heard the engine rev higher as the plane pitched up into a climb. It turned left and passed out of sight. Then the boater heard the crash.

The plane had come to rest on the shore with the left wing in the water and the rest on land.

The cause of the crash was not immediately apparent. There was no fire, and all of the pieces of the plane were accounted for at the crash site. The plane did not strike a power line, as some had feared, given its low altitude.

NTSB investigators are now writing up a preliminary report, to be issued tomorrow or Saturday. (UPDATE: It’s now available here.)

It is of course impossible to understand the cause of a crash without a full investigation. One possible scenario that investigators will likely explore is the possibility that the pilot pulled up too steeply at the edge of the lake and caused an accelerated aerodynamic stall. In this condition a too-high angle between the wing and the relative wind causes the former to abruptly lose lift. At the accident airplane’s low altitude, there would be little room to recover.

It is common practice for floatplanes to climb steeply when transitioning from low-level flight over water to flight over land, in order to avoid hitting obstacles such as powerlines.

The Icon A5, a sleek and sexy sport plane with seats for two, has generated enormous interest in the media, and was nominated for a Collier Trophy last year. More than 1,000 customers have reportedly laid down deposits. But the company has lately been troubled by production problems, and this crash will add significantly to its woes. Apart from the human tragedy, the accident will add expense and delay to the program as the company struggles to address whatever problems caused the crash.

Safety has been one of the primary selling points of the Icon; the company claimed that its design minimized the danger of spinning and stalling. A fatal crash is not a good look—especially if that crash turns out to have been caused by the very aerodynamic condition the plane is supposedly immune from.

If so, the story of Icon will go down as one of the dangers of engineering for safety: as with the Titanic, if you believe that you’re safe from danger, there’s an incentive to flirt with it.