Airframe icing is emerging as the likely cause of last week's fatal air crash that killed American car racing team owner Tony Bettenhausen, his wife and two business colleagues.

Bettenhausen, 48, was piloting his own twin-engined Beech Baron 58 from Florida to his home near Indianapolis when he reported ice on the wings and windshield of his aircraft and requested permission to climb. Moments later, says David Muzio of the National Transportation Safety Board (NTSB), the aircraft - which had been flying straight and level - plunged out of control into the ground near Lexington, Kentucky, registering a descent rate of 6,000-9,000ft a minute just before impact.

Compete

Bettenhausen Motorsports will continue to compete in this year's FedEx sponsored Champ Car (CART) series despite the death of the team's owner and his business partner Russ Roberts.

Mexico's highly-rated Michel Jourdain Jr will continue to drive the team's Lola-Ford car, with Tony's brother Merle - who lost an arm while competing in a car race in Michigan in 1972 - adopting the role of team boss.

Former racing driver Bettenhausen learned to fly single-engined aircraft in the mid-1990s but he had held a twin rating for less than a year. He bought the Beech Baron eight months ago.

Source: Flight Daily News