NTSB Factual Report

HISTORY OF FLIGHT

On December 30, 1995, at 1443 central standard time (cst), a Cessna 560, N991PC, piloted by an Air Transport pilot, was destroyed when it collided with the terrain approximately one quarter mile north east of the runway 22 threshold, at the Eagle River Airport, Eagle River, Wisconsin. The airplane was circling to land on runway 22 after being cleared for the VOR/DME approach by Minneapolis center at approximately 1425 cst. The 14 CFR Part 91 flight was operating on an IFR flight plan. The pilot and copilot sustained fatal injuries in the accident. The airplane departed from Des Moines, Iowa, en route to Eagle River Airport, at 1343 cst.

METEOROLOGICAL INFORMATION

The local weather observation at 1359 cst for Rhinelander, Wisconsin, was given to the pilots of N991PC by Minneapolis Center. Rhinelander was reporting ceiling 300 overcast, visibility one mile, with fog. The automated weather observing system (AWOS) at Eagle River, Wisconsin, was recording a partial obscuration, ceiling 600 overcast, visibility one and one quarter miles, temperature 29, dew point 28. A Vilas county sheriff captain, reported precipitation in the form of freezing rain/sleet at the time of the accident.

AIDS TO NAVIGATION

A flight check was conducted of the Rhinelander VOR and the Eagle River NDB on January 1, 1996, by the Federal Aviation Administration (FAA). No abnormalities were noted in either facility.

AERODROME INFORMATION

The Eagle River Airport was equipped with a AWOS which was commissioned on December 1, 1995. The AWOS was recording the local weather, but was not transmitting the weather on a VHF frequency, at the time of the accident. The Great Lakes Office of the FAA was contacted by the investigator in charge (IIC) on February 8, 1996. The FAA reported to the IIC that due to radio frequency congestion at the O'Hare International Airport, Chicago, Illinois, no VHF frequency had been assigned to the AWOS station at Eagle River Airport.

The IIC contacted the Wisconsin Department of Transportation during the course of the investigation. During the last conversation with an employee of the Wisconsin Department of Transportation on May 10, 1996, no VHF frequency had been assigned to the AWOS station at Eagle River, Wisconsin, and the employee did not know when a frequency would be assigned.

FLIGHT RECORDER

The airplane was equipped with a cockpit voice recorder (CVR) which was replayed and transcribed at the National Transportation Safety Board's office in Washington, D.C. on January 31, 1996. The final 20 minutes and 56 seconds of the CVR tape are included as a supplement to this report.

WRECKAGE AND IMPACT INFORMATION

Wreckage documentation, control continuity and cockpit documentation were conducted on December 31, 1996. The airplane wreckage path followed a magnetic heading of 320 degrees, and covered a distance of approximately 350 feet. The left wing and horizontal stabilizer leading edges had approximately one eighth inch of rime ice adhering to their leading edges. The cockpit area of the fuselage sustained extensive crushing and came to rest inverted. Due to the amount of crushing which was sustained by the cockpit area, only limited cockpit documentation was possible on December 31, 1995. The airplane was moved to the Eagle River Airport on the evening of December 31, 1995. During the process of moving the aircraft to the Eagle River Airport fuel was observed running out of the wing tanks of N991PC.

On January 1, 1996, the instrument panel was removed from the wreckage and the areas which could not be documented on December 31, 1995, were documented on January 1, 1996. Airframe inspection revealed no abnormalities with the airplane.

The airplanes right wing was crushed, the nose gear and right landing gear were separated from the airframe. The fuselage fractured at the aft pressure bulkhead and main cabin door areas. Both the horizontal and vertical stabilizer had separated from the aircraft. The vertical stabilizer had folded down on top of the upper surface of the left horizontal stabilizer. All four wing flaps were separated from the wing.

MEDICAL AND PATHOLOGICAL INFORMATION

On January 1, 1996, an autopsy was performed on the pilot and copilot by the Vilas County Coroner, Route 2 Box 251, Manitowish Waters, Wisconsin. Toxicological testing conducted by the FAA, was negative for all tests conducted, on the pilot and copilot.

TESTS AND RESEARCH

Examination of the engines on December 31, 1995 revealed the following. The thrust reversers for both engines were found in the closed position. Both engines contained a small area of ice approximately five inches in diameter, which had formed beneath the final turbine wheel. The right engine had separated from its mount and ingested a large amount of green insulation. Small pieces of insulation were found in the tail pipe area of the right engine. After preliminary examination both engines were placed in shipping containers and shipped to the manufacturer's overhaul facilities in Burlington, Vermont, for further examination.

At the manufacturer's facilities both engines were inspected on January 10 and 11, 1996. No abnormalities were noted and indications of power at impact were found on both engines. The full inspection report for both engines is included as a supplement to this report.

Five witnesses gave written statements to the IIC. Two witnesses reported seeing the airplane rolling from the left to the right. One witness wrote "It was teetering like a see-saw from side to side." A third witness wrote that N991PC was very low and started a left turn with approximately 90 degrees of bank angle, then banked 45 degrees to the right and struck the ground with the right wing tip. Two of these witnesses went up to the accident site and reported seeing fuel coming out of the airplane's fuel tanks.

ADDITIONAL INFORMATION

Parties to the investigation were the FAA, Pratt & Whitney, Cessna Aircraft Corporation and the Iowa Packing Company.

NTSB Probable Cause

the failure of the pilot to maintain airspeed while executing the circling approach. Factors were the descent below minimum descent altitude, the fog, the low ceiling and the icing conditions.