The pilot reported that, during the descent to the airport in Lexington, Texas, he applied carburetor heat but that he then removed carburetor heat when leveling off.
He reduced the throttle to slow the Cessna 182 while on final approach. When he advanced the throttle to maintain airspeed, the engine power did not increase and he was unable to restore full engine power. The engine subsequently lost all power when he applied carburetor heat.
During the forced landing to a field, the nose landing gear and propeller hit a barbed wire fence, and the airplane then nosed down, hit the ground, and nosed over.
The atmospheric conditions at the time of the accident were conducive to the formation of serious carburetor icing at glide power. It is likely that carburetor ice developed after the pilot reduced the engine power/closed the throttle while in the traffic pattern without applying carburetor heat, which resulted in a loss of engine power.
The manufacturer’s before landing checklist states to apply carburetor heat before closing the throttle.
The NTSB determined the probable cause as the pilot’s improper use of the carburetor heat, which resulted in a total loss of engine power due to carburetor icing.
NTSB Identification: CEN14LA133
This February 2014 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.
The gentleman with the 182RG If my memory serves me right the 182RG has a Lycoming 0-540 engine dosent it ?? thus the carb is right on the oil sump keeping things a little warmer. Also if I may add most pilots are taught to enrichen the mixture when pulling the power back and setting up for a landing in other words push the mixture in, I can say without reservation that before you enrichen the mixture on desending ” leave the mixture alone where it is this will keep the engine worm all the way down till touchdown, fuel as you all well know is a coolent and it works very well to cool, I don’t know why people are told to enrichen the mixture when decending, all this does do especially on Cont. engines is guarantee ice. Next time your decending do not enrichen the mixture you wont need carb. heat..enjoy.
I teach A&P students at a technical college, where we have several run stands with Continental O-470’s, . To make the point about how susceptible these carbureted engines are to icing, as well as how important a properly operating carb heat system is, I’ll have the student operator reach around the windscreen and touch the intake manifold near the carb. They are always amazed how cold it is, even on a summer day–and if it’s a humid day, there’s quite a bit of condensation formed on the outside of the manifold. Makes a dramatic point how the combined temperature drop from the vaporization of AVGAS and from the pressure drop through a venturi can easily get you to the ice-forming situation.
In the 10 years I’ve owned a182 RG operating colder temperatures I’ve never use carburetor heat once!
I highly recommend a Carb Temp guage for all 0-300 and 0-470 powered Cessnas. It was an eye opener for all my students to learn and see, just what the temperature was in the throat of the carb during all phases of engine operation on the ground and in flight. In particular, full throttle on takeoff and climbout, and again on the cruise descent from altitude down to pattern altitude. That’s where your lowest carb temps will be and in the right OAT and humidity conditions you will start forming the ice. And then at power reduction in the pattern you’ll see the carb temp warm up (even without Carb Heat on) and the ice will start melting and then the engine sputters and/or quits. The carb heat control should be used as an anti-ice control and not de-ice, and you need the carb temp guage to do that. I will not fly in IMC without a carb temp guage with those engines; just like I won’t fly in any airplane that doesn’t have shoulder harnesses.
All carbureted Continentals have the same issue with Carb Ice. The placement of the carb away from the engine heat adds to this problem. Franklin engines the same. The Lycoming engine carburetor is mounted on the oil sump for a reason (warmer). The carb heat should be left ‘on’ while in the pattern once you have applied it. I have had ice in the little A65’s as well as the O-300 series engines.
Interesting. The only airport there is a skydiving center. They recently lost a plane, I think it may have been the same 182. I hear it was a low pass and pull up into a stall/spin.
Different airplane.
Runway buzz job into a failed chandelle, half turn spin, vertical impact.
CEN15FA427
09/27/2015
According to the NTSB docket the weather at METAR reported 19 dC ambient and 13 dC dewpoint temperatures. The Carb Ice probability chart (http://dms.ntsb.gov/public/56000-56499/56061/550963.pdf) shows this as 80% RH, and in a zone of potential icing at glide and cruise power. The aircraft was a 1956 C182. It’s POH descent and glide checklists say apply carb heat. According to his statements in an interview with the NTSB and in the Pilot/Op report (see the docket) he used carb heat for a long descent from 10,000′ MSL to about 1,000′ MSL after “jumpers away”. Then as he leveled off turned off the carb heat, though he was still at a low power setting and therefore not producing a lot of power. The engine probably lost quite a bit of heat during that descent. I saw no mention of whether he closed cowl flaps during his descent. From my own experience in later model C182 aircraft, carb heat is important during any low power situation, especially if RH is high, like it was that fateful day.
Why didn’t the 2nd application of the carb heat improve the situation? Was it to late? To much ice?
Because carb ice had formed again and narrowed the carb throat during the interim between the first and second application of carb heat. Thus when carb heat was applied the second time the mixture was super rich (less airflow volume of a less dense air) which flooded and killed the engine. The heated air is less dense than ambient thus the fuel-air ratio is enriched when carb heat is applied especially so if the mixture was already set to full rich as is typically done in compliance with the before landing checklist.
Possibly got a slug of water from all the ice when he applied heat the second time or possibly the ice had restricted the the venturi so much that when he applied heat the second time the mixture was so rich it flooded the engine. Just guessing.
182s = notorious ice machines, otherwise fantastic stout aircraft
The docket says severe icing was possible (19 dC ambient, 13 dC dewpoint and 80%RH). He made a very long descent from “10,000-10,500′ MSL” to about 800 ‘ AGL (1300’ MSL). He increased power a small amount and removed carb heat when he leveled after descent. Then he reduced power to descent to land. The engine was likely cold in his C182A, so potential was there for a lot of ice… and a lot of water going into his cold engine when he finally applied carb heat as he noticed the loss of power.
It’s easy to see how it could happen.