9 hours ago, sloppysmusic said:

the Low Thrust Warning will NOT illuminate before or during this event

Low thrust detectors only detect a difference in thrust (measured by pitot tubes) between engines, so If they are both set exactly the same in the sim, the lights will not illuminate.

On 5/16/2024 at 2:43 PM, JRBarrett said:

It’s possible, but absolutely not recommended. With a turbocharged engine, you will typically use full boost and maximum prop RPM on takeoff, but will reduce manifold pressure and prop RPM once established in a climb. On the Duke, I have typically been using 35 inches MP and 2400-2500 RPM. 

Thanks, it makes sense. Just checked the manual, normal checklist. 35.5/2750 + mixture max power for enroute climb. Not sure if mixture max power refers to full rich or ROP*. To me the latter makes sense. 

*leaning for best power is probably a good idea throughout the climb, although it is technically possible to run full rich until CA. Problem is, we don’t know when we hit CA. So perhaps starting to lean above 20,000 would make sense, as the decrease in MP can be hard to spot. 

Edited May 18, 20242 yr by Cpt_Piett

7 hours ago, MattNischan said:

In any case, without using the new turbo/mixture/fuel parameters introduced in SU13, it is actually not possible to tailor the steepness of the rich power cutoff region in the sim

It's the steepness, or 'instantaneous lack of power' at 'changeover' from turbo handled power to NA type mixture handling power that is the heart of the problem. I think you are saying that because the the Duke is so advanced it showcases a major design flaw in the sim. Or something like that. 

Whatever is the cause it's not in any like any real plane. That instant death toggle mix instant restart instant death instant mix restart behaviour. 

Something I'd forgotten from my first reporting of this issue happened again last night. Used fshud for an Aussie short flight 250nm. Cleared to ff 200 cruise. On great that was good to hear. No issues with full power climb to 20k. Leveled off. Dropped mixture off a tad but made no noticeable difference (as it shouldn't at 20k) so returned to full. 

Atc then cleared me to fl240. The hairs at back of my neck rose but.. That's still safe so full steam up ahead I went. Leveled off again 24k no problem once again tested mix made tiny change with power so left it full on adjusted mp /prop for cruise. Prop middle of green band from memory and mp circa 38/39. Pretty much max as it drops off from 41 - 39 approaching CA (before predictable instant total engine fail). 

Everything was so pleasant I forgot about previous issues and enjoyed the scenery. 

Cleared for arrival descend to FL180. 

OK! Select ATT dial down alt selector and pressed invisible up arrow to start descent. When air speed was toward top of white band where I wanted it started moving power and prop levers back in tandem to get the power I wanted for descent and POOF complete engine failure. 

Now educated in the unrealistic 'waggle mixture for instant restart' procedure I did that then followed a comical dance of adjusting power stalling engine restart over and over until I was safely at 18k where this behaviour dissapates. I'd earlier noted that 16k was the safe spot during descent where engine wouldn't die. 

Was lucky not to overstress the ac during all this lurching around. Once past 18k rest of descent was glorious and I experienced my first VOR A (+v!) approach. I'll look it up and post here in edit in a moment. 

Regarding this engine cutting out every flight issue: I'm not going to say the emperor is wearing no clothes because he is in fact well dressed but not quite perfect. He's wearing his tie but forgot to put a shirt on beneath it. Someone had to say it, sorry but it's true. 

 

YBTL Townsville. 

Appr was VOR 19. Offset approach with vertical tracking by ap. First time I ever encountered this. Pressing VLOC then APPR gave me an ILS like descent to my final turn to final. 

TURBOCHARGERS Better engine performance at altitude from AOPA

Mixture is important when you're operating a turbocharged engine. Leaning the mixture increases cylinder head and turbocharger turbine inlet temperatures significantly—and rapidly. The aircraft's pilot operating handbook (POH) recommends the proper leaning procedure and gives the maximum cylinder head and turbine inlet temperatures. Manufacturers typically do not recommend leaning when the engine is operated above 75 percent power.

Edited May 18, 20242 yr by sloppysmusic
Apr added - added AOPA training link

I dont care what you nerds say. 

 

I'm going on record saying the Duke Turbine is the most fun aircraft in the sim. 

 

You really have to keep an eye on everything you do or it might kill you. 

 

But if you do? It's so much fun and an absolute joy to land. 

 

Man I love it.  Airliners are stupid now. 

1 hour ago, JughedJones said:

Duke Turbine is the most fun aircraft in the sim

Oh yes it may be, keep an eye on engine temps and off you go..fast!

FSW Lear 35 is my other fast and fun plane. Both ac climb at ear popping rates 😄

New post as very useful link for Duke owners!

Duke Flyers Association - Every doc you wanted..

Top of list is full POH which contains every setting/chart/instruction you could possibly need to fly the B60 by the BOOK.

47 minutes ago, sloppysmusic said:

FSW Lear 35 is my other fast and fun plane. Both ac climb at ear popping rates

Yep the Lear is lots of fun. I like to fly one plane for months. In p3d I flew t duke for a year and a half. That’s probably why I haven’t bought for MSFS. 

1 hour ago, sloppysmusic said:

New post as very useful link for Duke owners!

Duke Flyers Association - Every doc you wanted..

Top of list is full POH which contains every setting/chart/instruction you could possibly need to fly the B60 by the BOOK.

Most interesting part for me from your site is this:

Cowl flaps are a high altitude cooling tool. Fuel is the engines primary cooling agent
during takeoff and climb, thus negating cowl flap usefulness below FL180. During
extended climbs above FL180 cowl flaps assist in keeping cylinder head and oil
temperatures within acceptable operating perimeters.
Ground Operations
Cowl flaps should be OPEN during all ground operations without regard to outside air
temperature. This technique prevents localized hot spots around the engine accessories
and associated wiring. Operators in the northern latitudes during extreme cold
conditions report keeping the cowl flaps CLOSED on the ground to facilitate oil
warming.
Takeoff and Climb
Cowl flaps should be CLOSED for every takeoff and climb and incrementally OPEN
in the climb to maintain cylinder head temperatures below 205° Celsius, or the oil
temperatures below 104° Celsius. With or without intercoolers, these engine
parameters should not be reached, even on the hottest day, until climbing through +/-
FL18.
Cruise, Descent, Approach and Landing
Cowl flaps will normally be CLOSED during cruise, descent, approach and landing,
since air flow provides sufficient cooling during these phases of flight.
Performance
Cowl flaps on a Duke are enormous. The increased wetted area of fully extended cowl
flaps increases induced drag. Think of the drag created by a flat plate, 3.25 inch tall, by
20.0 inches wide affixed below and perpendicular to each engine nacelle. This induced
drag increases takeoff distances, significantly decreased single and two engine climb
performance, and decreases cruise true airspeed.

1 hour ago, reecemj said:

. In p3d I flew t duke for a year and a half. That’s probably why I haven’t bought for MSFS. 

This will make me very unpopular here, but I really didn't like the Duke in P3D. I don't know what it was, but the engines always played tricks on me. On the other hand, I loved the Milviz B350 in P3D and was very comfortable with its systems.

The BS Turbine Duke for MSFS is a totally different plane for me than the RealAir Duke. I felt right at home in it, it has quite a bit of similarity with the 350. It probably is my favorite plane in MSFS right now. Highly recommended.

1 hour ago, sloppysmusic said:

New post as very useful link for Duke owners!

Duke Flyers Association - Every doc you wanted..

Top of list is full POH which contains every setting/chart/instruction you could possibly need to fly the B60 by the BOOK.

Thanks for the links!

Ironically  continues climb done with full mixture with no restrictions while performance tables goes all the way to 30000 ft. Leaning recommended only TIT below 900 degrees in cruise. Critical altitude is defined when desired  MP  RPM cannot be maintain 

So the only time engine quits is when power reduction is not slow at higher altitude without adjusting mixture

 

12 minutes ago, sd_flyer said:

So the only time engine quits is when power reduction is not slow at higher altitude without adjusting mixture

Exactly. Leaning is USUALLY performed (using the FC ideally) for increased power/speed (ROP) or better fuel consumption (LOP) during cruise. It has NEVER been a requirement to lean simply to keep the engines from quitting entirely. It's a tweak not a life saving procedure.

32 minutes ago, sloppysmusic said:

Exactly. Leaning is USUALLY performed (using the FC ideally) for increased power/speed (ROP) or better fuel consumption (LOP) during cruise. It has NEVER been a requirement to lean simply to keep the engines from quitting entirely. It's a tweak not a life saving procedure.

It looks like a bug that BS should address. Meanwhile, on the bright side turbine - Duke perforce as expected except fuel consumption for given power settings a bit off

40 minutes ago, qqwertz said:

2 hours ago, reecemj said:

 

This will make me very unpopular here, but I really didn't like the Duke in P3D

You good. We just have a different opinion. I’ll get the duke later this summer.😊

19 minutes ago, sd_flyer said:

Duke perforce as expected except fuel consumption for given power settings a bit off

Yes the Turbine is a cracker! It keeps you on your toes for all the right reasons. I'm sure minor tweaks will be released with future updates. Piston model needs a sooner fix though. Recognition of the problem would be fine. For most VFR sight seeing trips it's an absolute visual/audio JOY to fly. It's only for the boring long distance IFR people like me that want to get up to ceiling for endurance that it's seriously flawed.

5 hours ago, sloppysmusic said:

Regarding this engine cutting out every flight issue: I'm not going to say the emperor is wearing no clothes because he is in fact well dressed but not quite perfect. He's wearing his tie but forgot to put a shirt on beneath it. Someone had to say it, sorry but it's true

Understand your frustration, but I promise it's possible to operate this aircraft without constant flameouts, as I've done a flight at FL 290 without any issues. I'll share what worked for me in hopes that it helps. I'm certain this can be done better or more realistically, but it does seem to work.

I would recommend not thinking about critical altitude as a fixed number. Instead, watch for your manifold pressure starting to fall. Once it does, this is your clue to start leaning. Watch your EGTs as you do so. If they start dropping a lot, this is a sign of an over-rich mixture, so bring mixture back further.

Once you level off, set your cruise power by reference to the charts in the manual. This includes a fuel flow that you can use to set the mixture. You should be significantly leaned from full rich. (It's not clear to me from your description whether you leaned or left the mixture at full rich?)

Certainly, when you bring the power back for the descent, you don't want to be full rich - as once you reduce power, the turbocharger RPM will reduce, hence enrichening your mixture even further. (I assume this is what caused the flameout you got.) For me, it works to initially leave the mixture at its cruise setting. As you descend, the mixture will become progressively leaner, but this isn't an issue at the low descent power setting. Ultimately, I think I ended up lean of peak; when my EGTs started dropping noticeably, I enrichened the mixture to bring EGTs back up. Below 10,000 ft, you're probably fine bringing the mixture back to full rich if you need to level off with a high power setting.

As I say, this is just what works for me. Would appreciate insights from others on how they operate the piston Duke.