On July 22, 1989, a Cessna R172K (registration N736DA) operated by Robert B. Toenjes was involved in an aviation accident near Wisconsin Dells, WI. No fatalities were reported. Investigators recorded the probable cause as: FAILURE OF THE PILOT TO INSURE THE OIL FILLER CAP WAS PROPERLY SECURED WHEN HE SERVICED THE AIRCRAFT BEFORE TAKEOFF, AND SUBSEQUENT LOSS OF OIL AND OIL EXHAUSTION. THE TREE WAS CONSIDERED TO BE A CONTRIBUTING FACTOR. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During flight, a pilot heard a pop from the engine, noticed smoke and power loss, and observed oil pressure drop to zero. He shut off fuel and made an emergency landing, during which the left wing struck a tree. Post-accident inspection found a loose oil filler cap, and engine teardown revealed no mechanical defects.
Narrative
While en route, the pilot heard a "muffled pop" from the engine. Approximately 30 seconds later, smoke began entering the cockpit and the aircraft experienced some power loss. The pilot noted that oil pressure was decreasing and eventually reached zero. In response, the pilot shut off the fuel supply and executed an emergency landing. During the landing roll, the left wing struck a tree, resulting in damage to the aircraft.
Investigation Findings
A post-accident inspection revealed that the oil filler cap was loose and hanging from its chain. A subsequent teardown inspection of the engine found no evidence of mechanical defects that would have accounted for the oil loss.
What happened in the 22 Jul 1989 Cessna R172K accident near Wisconsin Dells, WI?
During flight, a pilot heard a pop from the engine, noticed smoke and power loss, and observed oil pressure drop to zero. He shut off fuel and made an emergency landing, during which the left wing struck a tree. Post-accident inspection found a loose oil filler cap, and engine teardown revealed no mechanical defects.
Were there any fatalities in the 22 Jul 1989 Cessna R172K accident?
No fatalities were recorded in this accident.
What aircraft was involved and where did it happen?
The accident on 22 Jul 1989 involved a Cessna R172K, registration N736DA, operated by Robert B. Toenjes, at Wisconsin Dells, WI.
What was the probable cause of the accident?
FAILURE OF THE PILOT TO INSURE THE OIL FILLER CAP WAS PROPERLY SECURED WHEN HE SERVICED THE AIRCRAFT BEFORE TAKEOFF, AND SUBSEQUENT LOSS OF OIL AND OIL EXHAUSTION. THE TREE WAS CONSIDERED TO BE A CONTRIBUTING FACTOR.
A SkyWalk Join't 3 paraglider crashed into the ground near Las Vizcachas, Chile, on September 1, 2024. The pilot and passenger sustained serious spinal…
PARAPENTE (ULTRALIVIANO NO MOTORIZADO)·2024-09-01DGAC Chile
A Cessna 172N struck electrical cables while on final approach to land at Aucó Aerodrome in Chile. The pilot was uninjured, but the aircraft sustained damage…
A Bombardier DHC-8-402 suffered a tail strike during landing at Puerto Williams on September 9, 2024. All 76 occupants were unharmed, but the aircraft…
A MYD JS-MD 3 glider veered off the runway and struck a wall at Vitacura Aerodrome on January 6, 2025. The pilot was uninjured, but the aircraft sustained…
A recreational paraglider flight in Puchuncaví, Chile, ended with the pilot sustaining serious injuries after a rapid descent and impact with a hillside on…
PARAPENTE (ULTRALIVIANO NO MOTORIZADO)·2025-03-29DGAC Chile
A Tecnam P2006T landed on its belly at an aerodrome in Poland after the crew failed to confirm landing gear deployment. The incident resulted in no injuries…