mixture leaning

[Bobsk8 12,848]

3 minutes ago, SAS443 said:

Fuel flow...usually measured in Gallons per hour (GPH) in light planes IRL.

Yes Fuel Flow I get, never heard it expressed as FF...... When I lean the GA aircraft I fly, I see the fuel flow go down. 

[jcomm 5,986]

1 minute ago, Bobsk8 said:

Yes Fuel Flow I get, never heard it expressed as FF...... When I lean the GA aircraft I fly, I see the fuel flow go down. 

Bob,

take, say, the C152, or the C172, or any of the default reciprocating aircraft, or the Carenado Seminole, etc...

Climb to 4000' ( would do at 3000 or even lower, but the higher you go the bigger the discrepancy... ).

Check your Fuel Flow ( FF ) gauge and start leaning. FF will initially rise and, only after a while start decreasing. As we all know it should start decreasing right from the start of the leaning...

The higher you climb the longer the initial rise in Fuel Flow.

[Bobsk8 12,848]

36 minutes ago, jcomm said:

Bob,

take, say, the C152, or the C172, or any of the default reciprocating aircraft, or the Carenado Seminole, etc...

Climb to 4000' ( would do at 3000 or even lower, but the higher you go the bigger the discrepancy... ).

Check your Fuel Flow ( FF ) gauge and start leaning. FF will initially rise and, only after a while start decreasing. As we all know it should start decreasing right from the start of the leaning...

The higher you climb the longer the initial rise in Fuel Flow.

OK, I don't fly any default aircraft. I know the Arrow shows FF decreasing, not sure about the Seminole, will have to check it. 

 

I just tried leaning the JF Arrow and 6500 feet.  As I leaned, the FF went steadily down, no rise at all. So apparently if you have an aircraft that is not doing that, it is not MSFS fault but the aircraft itself. 

Edited April 11, 2022 by Bobsk8

[orchestra_nl 957]

1 hour ago, Bobsk8 said:

OK, I don't fly any default aircraft. I know the Arrow shows FF decreasing, not sure about the Seminole, will have to check it. 

 just tried leaning the JF Arrow and 6500 feet.  As I leaned, the FF went steadily down, no rise at all. So apparently if you have an aircraft that is not doing that, it is not MSFS fault but the aircraft itself. 

I just loaded up the default 172 classic (steam gauges) and did the exact same thing.
The EGT gauge works but it takes a while before it responds to mixture settings. That is probably realistic.

The FF does indeed rise when leaning until the mixture lever is at ~90%, then it remains more or less constant until the mixture lever is at ~50 when it starts to drop.
It seems the 172 could use an update.

[jcomm 5,986]

3 minutes ago, orchestra_nl said:

I just loaded up the default 172 classic (steam gauges) and did the exact same thing.
The EGT gauge works but it takes a while before it responds to mixture settings. That is probably realistic.

The FF does indeed rise when leaning until the mixture lever is at ~90%, then it remains more or less constant until the mixture lever is at ~50 when it starts to drop.
It seems the 172 could use an update.

It's common to all reciprocating engines in fs9/fsx/p3d/mfs... Long awaiting update.

Maybe they'll fix it in an upcoming SU. 

Well, in atotally unrelated issue, they did fix the roll rate limitations with SU6 or 7 I don't exactly recall, and now the roll rates can cope with realistic Extra 300 like performance.

So, there's always hope, but this one is intrinsically related to the way reciprocating engines are modelled in MS FS.

Edited April 11, 2022 by jcomm

[Bobsk8 12,848]

8 minutes ago, jcomm said:

It's common to all reciprocating engines in fs9/fsx/p3d/mfs... Long awaiting update.

Maybe they'll fix it in an upcoming SU. 

Well, in atotally unrelated issue, they did fix the roll rate limitations with SU6 or 7 I don't exactly recall, and now the roll rates can cope with realistic Extra 300 like performance.

So, there's always hope, but this one is intrinsically related to the way reciprocating engines are modelled in MS FS.

I guess you missed my post, the JF Arrow has a reciprocating engine, so your conclusion is not quite accurate. 

[orchestra_nl 957]

10 minutes ago, Bobsk8 said:

I guess you missed my post, the JF Arrow has a reciprocating engine, so your conclusion is not quite accurate. 

But we still do not know whether it is an issue in MSFS that JF has learned to work around, or that it is just an error with some of the default aircraft.

[Waldo Pepper 1,953]

If you're lazy you can map "Set Best Mixture".    I use it when I fly the Extra 300.