[Juan Infante]

Juan Infante on July 28, 2021 at 6:49 am #20802

Hi John,

I fly in south and central Florida behind the J3A5D variant in the Dakota which is the same as your engine except for a bit of derating. I never use carb heat during landing. I have not had a problem. Of course, anything can happen any time, but one thing that I notice is that I get into the yellow arc of the carb temp (JPI 900) while in cruise but I don’t remember ever seeing that during landing. Given the position of the carburetor and the inherent design benefits already described, I am not worried. I do not think that you should be either, but ultimately you have to do what makes you feel safe.

[John]

John on May 28, 2021 at 1:12 pm #20681

Hi Steve,

Thank you so much for the detailed explanation. This makes sense for the disparity in procedures. I want to extend the life of my engine as long as possible. I did find a Lycoming service instruction, 1148C, that recommends only using when the possibility of icing is suspected. It says overuse can reduce the life of the engine. I will go with that recommendation and add the carb temp gauge to my instrument scan.

Thank you again

Attachments:

• UseofCarburetorHeatControl.pdf

[STEVE]

STEVE on May 28, 2021 at 9:59 am #20678

Hi John;
The induction system (carburetor, induction system) of a Lycoming is a heated system since the carburetor is bolted directly onto the bottom of the engine oil sump, and since the induction tubes are cast into the engine oil sump.
When the oil is up to operating temperature, this automatically heats the system, making the possibility of carburetor icing less likely than icing of a Continental engine.
Continental engine induction systems are isolated from the oil sump. There is certainly warm air surrounding the induction system of a Continental engine but it’s not heated as well as a Lycoming system.
There’s no problem in adding carb heat to a Lycoming powered engine, especially if flying in visible moisture (clouds, foggy conditions, rain) conditions but as the book says, as needed.
I fly a Lycoming power PIper airplane and since I’m pretty much a day VFR flyer, I very seldom add carb heat.
Applying carb heat is your decision. The only detrimental result is letting unfiltered air into the engine when carb heat is on. And a light richening of the fuel/air mixture.
Let me know what you decide.
Steve

[John]

John on May 25, 2021 at 6:44 pm #20669

Hi Everyone,
Total newb question here. I have a new to me PA32-260. During flight training we always applied carb heat during the landing sequence in the Cessna. The POH for the Cherokee Six says as needed. My thinking is to ensure I don’t get caught with the Venturi effect and inadvertently cause an engine out emergency, that it shouldn’t hurt to apply carb heat. Am I correct in my thinking or is there a reason to not apply carb heat during the landing sequence? I would greatly appreciate any help or suggestions.

JC