PDA

View Full Version : Leaning the A36...



jcomm
03-22-2005, 07:12 AM
Well, I am so overwhelmed by the performance of the A36 that I keep leaving back a few minor details. One of the very few problems with systems modelling I came accross was when leaning during climb/cruise.

Today I took some time to take my notes, based on real world+ELITEv8+fs9A36.

Here I am flying over Lisbon, with current weather. Cruising at 10000', OAT -5.1C. 21.0HG, 2108 RPM and EGT reading 520C shows a FF of 10.7 GPH. The mixture is already leaned from full reach.

I further lean, and the following "table" shows the EGT and FF results:

EGT FF
542C 11.0GPH
562C 11.2GPH
597C 11.6GPH
622C 11.9GPH
644C 11.7GPH


So, apparently there is something wrong going here. As I lean I should get decreasing FF (allways!!!), but it keeps rising until I get to around 622C. Only after that point will further lean decrease FF. This is strange...

Comments?

jcomm
03-24-2005, 05:59 AM
I believe this "leaning bug" belongs deeper in the core of MSFS. All of the GA prop aircraft I have tested "suffer" from the same anomaly...

Maybe it'll work in fs10 ....

jcomm
03-26-2005, 05:49 PM
Sorry for insisting, but I would really appreciate if someone from the A36 crew could comment on this leaning figures.

My point is that there must be something wrong because in the data included above it is clear that as I lean FF grows, which is exactly the opposite of reality. But maybe there is something more to it than I know?

What about the real world A36 driver who helped in the design process?

Thx in advance for any answer!

ToddNicholson
03-26-2005, 07:53 PM
In FS, I do notice that when you begin leaning, FF will actually increase slightly, then begin to decrease as normal. I've seen this in virtually all aircraft. It's just the way FS is. Using the actual cruise charts found in the manual and leaning using the digital gauge, FF rates are just about spot on correct for the given temperature, Altitude, MP and RPM setting.

sclincoln
03-27-2005, 10:44 PM
In the fixed prop planes, leaning at altitude does cause a similar increase then decrease reaction with rpms. I wonder if MS just tied fuel flow together with that effect.