This February 2007 accident report is provided by the National Transportation Safety Board. Posted as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Cessna 340A.
Location: Council Bluffs, Iowa.
Injuries: 4 Fatal.
Aircraft damage: Destroyed.
What reportedly happened: The pilot held an airline transport certificate and had logged about 3,275 hours. He was instrument current and had logged several hours of flight time in the week preceding the accident. He obtained a pre-flight weather briefing that included a warning about moderate icing, turbulence and low-level wind shear in the vicinity of the destination airport. The briefer also provided several pilot reports for icing and turbulence.
The pilot was attempting a VOR approach. Radar data indicated that the airplane passed the VOR at an altitude of 2,800 feet MSL, then turned right to a heading of 017°. The published final approach course for the approach is 341°. Radar data showed the airplane wandering all over the sky.
The minimum descent altitude for the approach procedure was 1,720 feet MSL. The airplane descended to 1,400 feet, then radar contact was lost. The wreckage was found less than a quarter of a mile from the runway.
The post-accident inspection of the airframe and engines did not reveal any anomalies associated with a pre-impact failure or malfunction.
Probable cause: The pilot’s continued flight into adverse weather, and his failure to maintain altitude during the instrument approach. The severe icing, moderate turbulence, and low-level wind shear were factors.
For more information: NTSB.gov/ntsb/brief.asp?ev_id=20070222X00212&key=1.