VALPARAISO, IN, USA
N157JW
CESSNA 310L
IMMEDIATELY FOLLOWING A NEW FREQUENCY ASSIGNMENT, WHILE DESCENDING INTO A CLOUD LAYER WITH REPORTED MODERATE TURBULENCE AND MODERATE RIME ICING, THE PILOT REPORTED 'I HAVE A LITTLE VACUUM FAILURE. I'M GONNA CLIMB OUTTA HERE.' EXAMINATION OF THE WRECKAGE REVEALED NO EVIDENCE OF AN AIRFRAME OR ENGINE MALFUNCTION. BOTH VACUUM PUMPS OPERATED NORMALLY WHEN BENCH TESTED AND INSPECTION OF ALL VACUUM SYSTEM COMPONENTS REVEALED NO EVIDENCE OF PREIMPACT MALFUNCTION. THE DRUMS ON THE VACUUM DRIVEN VERTICAL AND HORIZONTAL GYROS, AND THE ELECTRIC TURN AND BANK GYRO, SHOWED SUBSTANTIAL ROTATIONAL SCORING.
HISTORY OF FLIGHT On February 5, 1995, at 1101 central standard time, a Cessna 310L N157JW, was destroyed when it impacted the terrain near Valparaiso, Indiana. The private pilot sustained fatal injuries. The personal flight, conducted under 14 CFR Part 91, departed Pontiac, Michigan, at 1058 eastern standard time, with a planned destination of Chicago, Illinois. Instrument meteorological conditions prevailed and an IFR flight plan was filed. According to voice transcripts and statements provided by air traffic controllers at the South Bend Airport Traffic Control Tower, South Bend, Indiana, at 1048, N157JW was cruising at 8,000 feet mean sea level and was instructed to descend and maintain 5,000 feet. At 1049, the controller instructed N157JW to maintain 7,000 feet and stated "I got reports of moderate ice and moderate chop at five maintain seven thousand for now." N157JW acknowledged a clearance to descend to 4,000 feet, at 1055. The pilot of N157JW acknowledged a frequency change to Chicago Approach Control at 1100:40, but did not report on the new frequency. A review of the voice tapes from South Bend Approach Control disclosed a weak transmission at 1101:17, "ah this is seven juliet whiskey, I have a little vacuum failure. I'm gonna climb outta here." A pilot report (PIREP) provided by the FAA indicated that the pilot of a BA-31, at 0930, had reported moderate rime icing and moderate turbulence at 5,000 feet over Gary, Indiana. WRECKAGE AND IMPACT INFORMATION The NTSB on-scene investigation began at 1630 on February 5, 1995. The wreckage was located in an open field approximately four miles northwest of the Porter County Municipal Airport, Valparaiso, Indiana. The wreckage was covered with drifted snow. Excavation disclosed the engines remained in the impact crater approximately eight feet below the surface of the field in a near vertical, nose down attitude. The fragmented wings and fuselage were scattered on the north edge of the crater. Fragments of the upper fuselage, and cabin were scattered for several hundred feet to the north of the crater. The smell of fuel permeated the scene. The blades of both propellers were separated from the hubs and exhibited severe bending. Inspection of the engines revealed no evidence of preimpact malfunction. The left main fuel tank was ruptured and contained several gallons of clear blue fuel. All airframe components were identified at the scene and inspection of flight control continuity revealed no evidence of preimpact malfunction. The landing gear bellcrank was in a position corresponding to landing gear up. The flap actuator was in a position corresponding to flaps up. The two engine driven vacuum pumps were retained for laboratory examination. The vacuum filter was shredded and soaked with snow. The paper filter element was slightly soiled. The vacuum gauge exhibited minor impact damage. The glass was missing and the face was distorted. The needle was pointing off of the scale in a downward direction. The right vacuum warning indicator was trapped in the suction position by the distorted face. The position of the left suction indicator was indeterminate. Inspection of the vacuum check valve assembly revealed that the rivets on one side of one valve assembly were stretched and broken. A search of the accident site and the wreckage was conducted for the missing valve and cover but they were not located. The other half of the check valve assembly exhibited severe impact damage. The valve was disassembled revealing an intact flapper valve. The primary attitude indicator exhibited severe impact damage. The drum of the gyro exhibited substantial rotational scoring. Examination of the vacuum driven horizontal gyro and the electrically operated turn and bank indicator gyro revealed substantial rotational scoring on the drums. MEDICAL AND PATHOLOGICAL INFORMATION The autopsy of the pilot was conducted February 7, 1995 by the Porter Memorial Hospital Department of Pathology, 814 LaPorte Ave., Valparaiso, Indiana 46383. The results of FAA toxicological testing were negative for all tests conducted. TESTS AND RESEARCH The two engine driven vacuum pumps were examined at Aircraft Systems, Inc. in Rockford, Illinois. The right side pump was connected to a test bench and exceeded all tests specifications for a new pump. The left side pump exhibited minor impact damage and the drive was binding slightly. The rear cover was removed. The interior appeared normal except for a small amount of soil located in the pump. The soil was removed, the cover installed, and the pump was then bench tested. It also exceeded all test specifications for a new pump. ADDITIONAL INFORMATION Parties to the investigation were the Federal Aviation Administration Flight Standards District Office, South Bend, Indiana, Cessna Aircraft Company, and Teledyne Continental Motors. Following the on-scene portion of the investigation, the wreckage, with the exception of retained components, was released to Mr. David Kocher of Aviation Accident Investigation & Management, Cicero, Illinois. Retained components were subsequently returned to Mr. Kocher following laboratory examination.
spatial disorientation of the pilot while descending into the clouds. Factors were the moderate turbulance and snow.
Source: NTSB Aviation Accident Database
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