AD Followed PenAir and Other Icing Accidents
In its determination of the probable cause of the PenAir Caravan crash, the Safety Board also said that a factor contributing to the accident “was the lack

In its determination of the probable cause of the PenAir Caravan crash, the Safety Board also said that a factor contributing to the accident “was the lack of a preflight inspection requirement to examine at close range the upper surface of the wing for ice contamination when ground icing conditions exist.” Such a requirement is now on the books, the result of an AD issued in March following an FAA investigation into incidents involving Caravans during operations in icing conditions, including six accidents in the previous two icing seasons and nine events in the past few months. In addition to a visual check, the directive (AD 2005-07-01) requires a “tactile check” of the wing leading edge and upper surface (up to two feet behind the deicing boot as a minimum). In a December 2004 NTSB recommendation letter to the FAA, the Safety Board said it was concerned that there might be a “systemic problem with the airplane’s design or with the operation of the airplane.” More than 1,400 Caravans are in operation worldwide.