7 minutes ago, Cpt_Piett said:

thought (perhaps erroneously) that it would make sense to lean for best power or best fuel economy - well before CA. 

It DOES make sense in current addon as the modeling is off. Irl if needed then your tc is defective so off to the hanger it goes! The entire purpose of tc is to force pressured air into engine (very simple explanation lol) so engine 'thinks' it's at msl all the way to ca. Then you would START to lean in the same way you'd start to lean when climbing a NA engine. Process should be gradual with no sudden cut off points. Best way to explain lean from ca would be say if ca was 24k then from 24k to 30k lean the ac in a similar way you would in na (naturally aspirated) plane like a trainer from ground level to 6000ft. The turbo is basically fooling the engine that msl is at ca. Wastegate is fully closed then. Turbo does not suddenly stop working at ca its like it's holding the pressure in. If it DID stop working at ca then yes that would kill the engine immediately like sudden decompression would knock out humans in the cabin at that altitude. 

1 hour ago, sloppysmusic said:

Process should be gradual with no sudden cut off points.

My knowledge of turbocharged pistons is too limited to be able to comment on this. If what you're saying is true, I'm confident that Black Square will rectify this in future updates. 

What I would like to know though, is when it's recommended to start leaning. In my current flight, I started leaning ROP (for best power) above 12,000ft. When I reached cruise, I repeated the process, leaning to about 30°C ROP, as per the section on the EDM 760 in the manual (page 129). 

I think there might be a typo in that section, as it says:

Quote

The final step is to enrich the engine’s mixture setting to the desired EGT for best power cruise. At cruise power settings, this point is approximately 50-100°F (28-56°C) below peak EGT for best power.

I think it should say above peak EGT (for best power). In the LOP section below, it also seems wrong:

Quote

The final step is to lean the engine’s mixture setting to the desired EGT for best economy cruise.
At cruise power settings, this point is approximately 25-50°F (14-28°C) below peak EGT for best
power.

I think this should read for best fuel economy. 

...

Besides this, I'm currently very happy at FL250 en route to Canberra, with Beyond ATC running. Got radar vectored out of Melbourne, and now being vectored into YSCB. Unfortunately ATC gave me an RNAV approach and I didn't choose the TDS GTNXi...

EDIT: Apologies in advance if what I wrote is incorrect, as it got a bit busy there in the cockpit 😉

Edited May 20, 20242 yr by Cpt_Piett

4 hours ago, Orlaam said:

Works just fine.  I have no idea what happens with the VLOC button, I just select the ILS frequency after picking the approach in the PROC page.  I never press the GPS/VLOC button.  It's worked perfect for me on ILS or RNAV/LPV glidepaths down to minimums each time.

2 hours ago, JetCat said:

I think it needs to be kept in GPS mode when an autoflight ILS approach is selected in GPS after having followed the mangenta line.

Thanks, I’ll try leaving it in GPS next time.  I’m in the habit of switching to NAV from GPS for ILS approaches and I thought VLOc was the same thing but maybe I’m misunderstanding.

2 hours ago, Cpt_Piett said:

What I would like to know though, is when it's recommended to start leaning

This in a real TC engine is simple: When critical altitude is reached during a climb (or during high altitude cruise IF you fly into/out of a storm!). CA being different every flight you can tell you passed CA the MOMENT MP starts to fall even slightly. That means the TC can no longer keep MSL pressure, wastegate is fully closed and due to thinner air the mixture is now getting slowly richer every hundred feet you climb. Leaning BEFORE CA during a climb is counter productive. If you find yourself NEEDING to do this the aircraft is trying to tell you something! Best to listen 😄

THE TC is most efficient at doing its job when power/prop maxed out. Plane will need servicing earlier but it's a tradeoff between maximum performance/safety during climb and reduced service costs.

If you buy a high performance car it WILL need less servicing if you never red line it and short shift all the time.

But....🤔😉

9 hours ago, Orlaam said:

Works just fine.  I have no idea what happens with the VLOC button, I just select the ILS frequency after picking the approach in the PROC page.  I never press the GPS/VLOC button.  It's worked perfect for me on ILS or RNAV/LPV glidepaths down to minimums each time.

Depending on the software level of the Garmin navigator, it may be capable of autoswitching to VLOC mode for an ILS approach.  That would explain what you are experiencing. IF you look closely, you should see the GNS or GTN in GPS mode for an RNAV/LPV glidepath, and in VLOC mode for an ILS glideslope. 

You can also manually switch to VLOC mode for an ILS landing.. Something I do out of habit.

Edited May 20, 20242 yr by Bert Pieke

2 hours ago, Bert Pieke said:

You can also manually switch to VLOC mode for an ILS landing.. Something I do out of habit.

Me too, but still puzzling why it wouldn’t intercept.  I manually dialed in the ILS frequency and course.  The aircraft registered the existence of the localizer and glideslope but didn’t grab them.

Had no issues capturing the ILS glideslope using the TDS for RWY 7 at KSBA.  It's my go-to spot for testing this in any new plane. I always follow these steps:

- Confirm NAV1 is tuned to ILS frequency (in this case 110.3) and that it's swapped as the active freq.

- Confirm VLOC is selected as NAV source after passing the IAF (in this case, HABUT)

- Confirm APPR mode is armed

- Confirm I am intercepting the glideslope from just underneath it at the final approach fix (in this case, just below 1800 ft at NAPPS)

If you do all that at KSBA you should be successful.

10 hours ago, Cpt_Piett said:

My logic behind leaning did not have anything to do with critical altitude. Although the turbocharged piston CAN be flown up to CA without any leaning, I thought (perhaps erroneously) that it would make sense to lean for best power or best fuel economy - well before CA. 

Of course, when approaching CA, it would make sense to start leaning, to prevent loss of power. 

This is also a reply to @martinboehme 😉 

If you're climbing at max continuous power (which is full throttle in the Duke), you definitely don't want to lean, as the additional fuel from the rich mixture serves to cool the engine as it evaporates.

I just did a test flight because I suspected that a cruise climb might possibly be a different matter -- but no, with the numbers recommended in the manual (35.5 inHg, 2,750 rpm, 194 pph) for a cruise climb, I'm still at full rich. In fact, even with a full rich mixture, I don't quite reach the 194 pph fuel flow quoted in the manual.

8 hours ago, Cpt_Piett said:

What I would like to know though, is when it's recommended to start leaning. In my current flight, I started leaning ROP (for best power) above 12,000ft. When I reached cruise, I repeated the process, leaning to about 30°C ROP, as per the section on the EDM 760 in the manual (page 129). 

AIUI, you should start leaning either when you reach critical altitude or (if you stay below critical altitude) when you set cruise power.

8 hours ago, Cpt_Piett said:

I think there might be a typo in that section, as it says:

Quote

The final step is to enrich the engine’s mixture setting to the desired EGT for best power cruise. At cruise power settings, this point is approximately 50-100°F (28-56°C) below peak EGT for best power.

I think it should say above peak EGT (for best power).

I think there's potential for confusion here because your mixture will be above what it was for peak EGT (this is what is meant by "rich of peak"), but the EGT will be below its peak value (obviously -- by definition, it can never go above peak EGT). When the manual says "approximately 50-100°F (28-56°C) below peak EGT", it's referring to the EGT value, which should be 50-100°F below the peak value that was observed. However, the mixture setting will be richer (and hence fuel flow will be higher) than it was at peak EGT. Hope this makes sense?

8 hours ago, Cpt_Piett said:

In the LOP section below, it also seems wrong:

Quote

The final step is to lean the engine’s mixture setting to the desired EGT for best economy cruise.
At cruise power settings, this point is approximately 25-50°F (14-28°C) below peak EGT for best
power.

I think this should read for best fuel economy.

Agreed, this looks as if it's a copy-paste error from the section you previously quoted.

5 hours ago, regis9 said:

Me too, but still puzzling why it wouldn’t intercept.  I manually dialed in the ILS frequency and course.  The aircraft registered the existence of the localizer and glideslope but didn’t grab them.

Happened for me for the first time on last flight. Before that: no issues. Couldn’t grab them, ended up doing a visual approach.

EDIT: ILS 06 EGPH

Edited May 21, 20242 yr by Cpt_Piett

4 hours ago, Stoopy said:

- Confirm NAV1 is tuned to ILS frequency (in this case 110.3) and that it's swapped as the active freq.

- Confirm VLOC is selected as NAV source after passing the IAF (in this case, HABUT)

- Confirm APPR mode is armed

- Confirm I am intercepting the glideslope from just underneath it at the final approach fix (in this case, just below 1800 ft at NAPPS)

Affirmative for all of the above. Could be something specific to EGPH, dunno 🤷🏻‍♂️ 

3 hours ago, martinboehme said:

I think there's potential for confusion here because your mixture will be above what it was for peak EGT (this is what is meant by "rich of peak"), but the EGT will be below its peak value (obviously -- by definition, it can never go above peak EGT). When the manual says "approximately 50-100°F (28-56°C) below peak EGT", it's referring to the EGT value, which should be 50-100°F below the peak value that was observed. However, the mixture setting will be richer (and hence fuel flow will be higher) than it was at peak EGT. Hope this makes sense?

It does. It’s easy to know if it’s rich of peak as fuel flow increases.

Also it makes sense not to lean before reaching cruise. Still getting used to the concept of TC, I’ve only got a few hours in the BS Bonanza. Still not sure if it might be a good idea to lean above 20,000ft as the CA will hit sometime after that. Sort of a precautionary measure I guess. As things happen VERY fast when MP starts to drop.

EDIT: With 2500/32 in cruise (as per the checklist), KIAS is quite low. Can’t remember the GS though. 

Edited May 21, 20242 yr by Cpt_Piett

31 minutes ago, Cpt_Piett said:

Affirmative for all of the above. Could be something specific to EGPH, dunno 🤷🏻‍♂️ 

Could very well be, that's why I gave specifics for KSBA if you wan to try there. Plus nicer weather there than England 🙂

51 minutes ago, Cpt_Piett said:

Happened for me for the first time on last flight. Before that: no issues. Couldn’t grab them, ended up doing a visual approach.

EDIT: ILS 06 EGPH

Thanks, I'll try again, maybe it was a one off issue.  In my case it was at CYXU.

9 hours ago, Stoopy said:

Could very well be, that's why I gave specifics for KSBA if you wan to try there. Plus nicer weather there than England 🙂

Haha, that’s probably true 😅 I’ve done ILS approaches elsewhere though, so it’s probably nothing Duke-specific