According to the pilot, after conducting an engine run-up and carburetor heat function checks, he switched to the Piper PA-28-180’s left fuel tank, then taxied for departure.
After taxiing to Runway 27 at Riverside Municipal Airport (KRAL) in California, he “had to wait a while” before being issued a takeoff clearance from air traffic control.
After takeoff and during the initial climb, about 1,000 feet AGL, the engine “sputtered and came back.”
The pilot verified that the mixture was full rich, the fuel pump was on, the left fuel tank was selected, and that the magneto switch was on both.
Shortly thereafter, the engine sputtered a second time, then lost total power.
The pilot initiated a forced landing to a nearby field. During the off-airport landing, the airplane struck terrain and came to rest upright about two miles west of the departure end of Runway 27.
While the pilot and one passenger were not injured in the crash, a second passenger sustained minor injuries.
Post-accident examination of the engine revealed that when the crankshaft was rotated by hand using the propeller continuity was established throughout the engine and valvetrain. Thumb compression was obtained on all cylinders. An alternate fuel source was plumbed to the right-wing fuel inlet port and the engine was run. The fuel source was removed and reattached to the left-wing fuel inlet port and the engine was run.
At 0953, the weather reported at KRAL included a temperature of 16°C and a dewpoint of 9°C. The calculated relative humidity was approximately 65%.
Review of the icing probability chart contained in FAA Special Airworthiness Information Bulletin CE-09-35 revealed that the weather conditions at the time of the accident were “conducive to serious icing at glide (idle) power.”
According to FAA Advisory Circular 20-113, “To prevent accidents due to induction system icing, the pilot should regularly use carburetor heat under conditions known to be conducive to atmospheric icing and be alert at all times for indications of icing in the fuel system.”
The circular recommended that when operating in conditions where the relative humidity is greater than 50%, “…apply carburetor heat briefly before takeoff, particularly with float type carburetors, to remove any ice which may have been accumulated during taxi and run-up.”
It also stated, “Remain alert for indications of induction system icing during takeoff and climb-out, especially when the relative humidity is above 50%, or when visible moisture is present in the atmosphere.”
Probable Cause: The pilot’s failure to use carburetor heat during an extended ground delay before takeoff, which resulted in a total loss of engine power during initial climb due to carburetor ice.
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This April 2023 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Most Marvel S carbs have a fitting to connect a carb temp gauge.
without a temp gauge, you won’t know if the temp is in the icing zone.!
I have one in my C175B and at an OAT of 45 degF I need to pull on carb heat shortly after a cold start, and use it during my taxi to the run up area.
Once the oil temp starts to increase, I can remove the carb heat.
I rarely need to use it in flight, only when the OAT is below 20 degF. I only need to use partial carb heat to get the carb temp out of the ‘yellow’ zone.
Carb heat is on the checklist for engine failure in flight: fuel selector, fuel pump, mixture, carb heat, engine gauges, primer locked. It’s critical to complete all six items.
Good to know.