Comanche How to Start.

[mryan75]

1 hour ago, sd_flyer said:

There are two types of engine. One sthat hard to start in winter and ones that hard to start in the summer LOL

So funny that you say that, I was thinking that exact same thing earlier. 

[Glenn Fitzpatrick]

On for start-up, off for taxi, on for take-off, off for normal flight and on again for landing.

 

 

[webstef68]

I have two questions for you specialists:

When do i need to activate the carb heater?

How do you manage the tanks? Why not simply and always open the two mains?

Thanks for the help 😉

[Ixoye]

1 hour ago, webstef68 said:

I have two questions for you specialists:

When do i need to activate the carb heater?

How do you manage the tanks? Why not simply and always open the two mains?

Thanks for the help 😉

1) When you get icing in the carburetor and on the final approach. (at low rpm)

2) I open both mains, why complicate things 😄

Edited August 20, 2023 by Ixoye

[Bobsk8]

8 hours ago, mryan75 said:

I’m not sure exactly what he’s doing there or why, to my knowledge you flood the carb by overpriming, not not running the fuel pump. Maybe this isn’t a carbeurated engine? But that would be an upgraded engine for sure. I can’t really say on this point. 

Yeah, I guess Scott doesn't know what he is talking about. Maybe he should hire you as his A2A technical advisor.  😉

Edited August 20, 2023 by Bobsk8

[mryan75]

1 hour ago, Bobsk8 said:

Yeah, I guess Scott doesn't know what he is talking about. Maybe he should hire you as his A2A technical advisor.  😉

Well I guess I had no need to try and be polite. I had it right the first time. 

[mryan75]

7 hours ago, Glenn Fitzpatrick said:

On for start-up, off for taxi, on for take-off, off for normal flight and on again for landing.

 

 

Yep, same for the Cherokees I’ve owned. 

Edited August 20, 2023 by mryan75

[mryan75]

4 hours ago, webstef68 said:

I have two questions for you specialists:

When do i need to activate the carb heater?

How do you manage the tanks? Why not simply and always open the two mains?

Thanks for the help 😉

Lycomings don’t tend to get carb ice because the carburetor is on top of the oil pan, so it stays warm. If you don’t have a carb temperature gauge (which most don’t) you basically only use carb heat when you suspect carb ice, which is when you get a drop in RPM or MP in flight. That’s one reason you want to be really precise with your RPM setting, so if it drops 50 RPM you can tell. So if you see a slight drop in RPM, push it back to where you had it, and if it drops again then you can really suspect carb ice, in which case you apply full carb heat. Carb heat is like being pregnant, there’s no such thing as a little pregnant. If you suspect carb ice, full carb heat. The other thing is a rough running engine. Sometimes you’ll get the RPM drop without a rough running engine, sometimes you’ll get both at the same time. In either case, full carb heat. 
 

And clearing carb ice can be nerve wracking, because as the ice melts and gets ingested through the carb, the engine will run even worse for a brief period of time. So you’ll have a rough engine, apply carb heat, and then it will start running worse, not better. That increases what my first instructor referred to as the “pucker factor.” But you have to leave the carb heat on and let it clear. If you turn off the carb heat at that point the ice can re-form past the carb-heat intake, and then there’s no way to clear it. Then you’ve really got a problem. 
 

The Cherokees I’ve had were all two tanks, left and right, so I’ll let someone else comment on that. But normally with multiple tanks in a wing you want to take off on the mains, run the tips dry in cruise (not dry, dry, some people like like to literally run a tank until the engine quits to make sure they use all the fuel - don’t fly with people like that), and then switch to the mains. 

Edited August 20, 2023 by mryan75

[Rimshot]

2 hours ago, mryan75 said:

Well I guess I had no need to try and be polite. I had it right the first time. 

Get used to it, Bob always knows best 😂

[Pivot]

Well I don't know whether it's wrong or right, but I have had no issues, at all, starting the Comanche. I have been flying in the US South which may matter too. Regardless of what the manual or starting procedures say, I give her 1-2 seconds on the fuel pump, then 1-2 pumps of the primer and she has yet to fail me. Some times I don't even turn the fuel pump on just use the couple primer pumps. THOUGH, I do have her fitted with the Fine Wire Spark Plugs, that may have an impact too.

Best bird in the cage as far as I'm concerned

[faldrath]

About using both tanks at once, one thing that was pointed out in the A2A forums is that if you do so, there's risk of unwanted fuel transfer between the tanks during turbulence/maneuvers (which isn't very serious), and if there's something wrong with the fuel system (leaks, contaminated fuel etc.), it's harder to identify which of the tanks is having the issue (which could be very serious). What I do, assuming both tanks have more or less the same amount of fuel at take-off, is switch tanks after 30 minutes and then again every hour afterwards.

[FrankR409]

1 hour ago, faldrath said:

About using both tanks at once, one thing that was pointed out in the A2A forums is that if you do so, there's risk of unwanted fuel transfer between the tanks during turbulence/maneuvers (which isn't very serious), and if there's something wrong with the fuel system (leaks, contaminated fuel etc.), it's harder to identify which of the tanks is having the issue (which could be very serious). What I do, assuming both tanks have more or less the same amount of fuel at take-off, is switch tanks after 30 minutes and then again every hour afterwards.

Very concise, thank you. I read this as well over at that forum. I only go at it with the fullest tank, and switch out about every 20 minutes or so.

[mryan75]

52 minutes ago, FrankR409 said:

Very concise, thank you. I read this as well over at that forum. I only go at it with the fullest tank, and switch out about every 20 minutes or so.

It’s really personal preference, but I would consider that too often. I agree with what was mentioned above: change 30 minutes after departure, and then once an hour after that. 

[FrankR409]

1 hour ago, mryan75 said:

It’s really personal preference, but I would consider that too often. I agree with what was mentioned above: change 30 minutes after departure, and then once an hour after that. 

I don’t disagree. I recreate flights that I would have otherwise driven to clients, those flights average around 1 hour to 1.5 hours.  I am notoriously cheap and carry a light fuel load as I am trying as best as possible to get the cheapest fuel possible and/or mitigate landing fees that might get waived with fuel purchase.  Hauling fuel burns more fuel.  So keeping the tanks as balanced as possible works for me.  I am planning a longer trip from KEKM > KHIB in about 3 weeks that will certainly have me topped up, and we will drain from the tips before we hit the mains, and surely it won’t be every 20 minutes.

I think we can all agree though, that this plane has created an enlightening experience into the subtle realities of ownership for everyone who is serious about GA.

Edited August 20, 2023 by FrankR409

[mryan75]

20 hours ago, FrankR409 said:

I don’t disagree. I recreate flights that I would have otherwise driven to clients, those flights average around 1 hour to 1.5 hours.  I am notoriously cheap and carry a light fuel load as I am trying as best as possible to get the cheapest fuel possible and/or mitigate landing fees that might get waived with fuel purchase.  Hauling fuel burns more fuel.  So keeping the tanks as balanced as possible works for me.  I am planning a longer trip from KEKM > KHIB in about 3 weeks that will certainly have me topped up, and we will drain from the tips before we hit the mains, and surely it won’t be every 20 minutes.

I think we can all agree though, that this plane has created an enlightening experience into the subtle realities of ownership for everyone who is serious about GA.

Are you talking real-world flights carrying light fuel, or sim flying?