NTSB Identification: CHI92FA020.
The docket is stored on NTSB microfiche number 45031.
Accident occurred Thursday, October 31, 1991 in ZION, IL
Probable Cause Approval Date: 12/15/1992
Aircraft: CESSNA 172P, registration: N5411K
Injuries: 1 Serious.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

THE SINGLE ENGINED AIRPLANE WAS OPERATING ON AN IFR FLIGHT PLAN AND CLIMBING THROUGH CLOUDS SHORTLY AFTER TAKEOFF. A WITNESS HEARD AN AIRPLANE'S ENGINE POWER SURGING AND OBSERVED A BRIGHT FLASH AT GROUND LEVEL SHORTLY AFTERWARDS. ANOTHER WITNESS OBSERVED THE AIRPLANE DESCENDING AND FLY PAST HIM JUST BEFORE SEEING A BRIGHT FLASH AND HEARING THE CRASH. THE AIRPLANE STRUCK AN ELECTRICAL POWERLINE AND TREE BEFORE COLLIDING WITH THE GROUND AND SLIDING TO A STOP. AN ON-SCENE INVESTIGATION REVEALED WATER IN THE CARBURETOR FLOAT AND ACCELERATOR PUMP CHAMBERS. THE COMMUTATOR OF THE TURN AND SLIP INDICATOR'S ELECTRIC MOTOR WAS FOUND WITH A GROOVE WORN AROUND IT AND A BLACK POWDERY SUBSTANCE PERMEATING THE INTERNAL MECHANISM OF THE INSTRUMENT. DURING AN INTERVIEW WITH THE PILOT, HE STATED THAT HE HAD TAKEN A FUEL SAMPLE FROM EACH FUEL SUMP ON THE AIRPLANE DURING HIS PRE-FLIGHT WALK AROUND INSPECTION. THE PILOT WAS UNABLE TO RECALL THE EVENTS WHICH TOOK PLACE AFTER ENTERING THE CLOUDS.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

WATER CONTAMINATION OF THE FUEL, AND THE PILOT'S INADEQUATE PREFLIGHT OF THE AIRCRAFT. FACTORS RELATED TO THE ACCIDENT WERE: DARKNESS AND OBSTRUCTIONS (TREES & TRANSMISSION LINES) IN THE EMERGENCY LANDING AREA.

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