It's been like this since ever, FS 2020 included...

Most if not all of the default twins or multiprops in fs 2024 exhibit completely unrealistic prop effects when the critical engine is failled, and all of the mltiprop addons I own suffer from exactly that same limitation.

I guess the default B58 is alread CFD-enabled, probably even the B350 (?), and the DC3, and now I have the Blackbird Simulations C130J and am able to fly it with #1,2,3 all failed and #4 at full power, in full manual mode, without having to care about it ???

Can someone please point me to an addon, preferably a free one, where the consequences of failling a critical engine show?

I always ask if the aircraft are already CFD-enabled at the payware support forums, like at the Blackbird forum, but get no answers, so I really don't know how good this new CFD is at replicating in a realistic way the asymmetries created under such scenarios.

I recall having tested it in FS 2020 by enabling CFD in the Baron and the B350 and the results were rather disappointing with both not requiring a big deal of correction over a very wide range of speeds and configurations (down to VMCA and bellow that IAS!).

Edited January 9Jan 9 by jcomm

8 hours ago, jcomm said:

It's been like this since ever, FS 2020 included...

Most if not all of the default twins or multiprops in fs 2024 exhibit completely unrealistic prop effects when the critical engine is failled, and all of the mltiprop addons I own suffer from exactly that same limitation.

I guess the default B58 is alread CFD-enabled, probably even the B350 (?), and the DC3, and now I have the Blackbird Simulations C130J and am able to fly it with #1,2,3 all failed and #4 at full power, in full manual mode, without having to care about it ???

Can someone please point me to an addon, preferably a free one, where the consequences of failling a critical engine show?

I always ask if the aircraft are already CFD-enabled at the payware support forums, like at the Blackbird forum, but get no answers, so I really don't know how good this new CFD is at replicating in a realistic way the asymmetries created under such scenarios.

I recall having tested it in FS 2020 by enabling CFD in the Baron and the B350 and the results were rather disappointing with both not requiring a big deal of correction over a very wide range of speeds and configurations (down to VMCA and bellow that IAS!).

This CFD is a new can of worms, because there are systems where the voxel count can affect performance, including frame rate and even stuttering. For the C130J engine out, you might want to try to add under the [AERODYNAMICS] 

normalizationmethod=0
CFD_EnableSimulation=1
CFD_ReinjectBody=1
CFD_ReinjectRotors=1
CFD_ReinjectVTailX=1 
CFD_ReinjectHTailY=1 
CFD_AirViscosity=0.03  
CFD_AirInCompressibility=0  
CFD_VoxelSizeScale=0.8  
CFD_VoxelNbVoxels=32  /try 28 if FPS drop
CFD_GroundCollisionVoxelOffset=1

21 minutes ago, LRBS said:

This CFD is a new can of worms, because there are systems where the voxel count can affect performance, including frame rate and even stuttering. For the C130J engine out, you might want to try to add under the [AERODYNAMICS] 

normalizationmethod=0
CFD_EnableSimulation=1
CFD_ReinjectBody=1
CFD_ReinjectRotors=1
CFD_ReinjectVTailX=1 
CFD_ReinjectHTailY=1 
CFD_AirViscosity=0.03  
CFD_AirInCompressibility=0  
CFD_VoxelSizeScale=0.8  
CFD_VoxelNbVoxels=32  /try 28 if FPS drop
CFD_GroundCollisionVoxelOffset=1

Wow! 

I Will surely try that!

Thanks👍

8 hours ago, jcomm said:

 

Can someone please point me to an addon, preferably a free one, where the consequences of failling a critical engine show?

 

What consequences of critical engine failure you expect? 

I find the single engine behavior of the A2A Aerostar to be pretty good.  You can absolutely do a proper Vmc demo.  I don't notice much difference between engines though; in other words, not specifically critical engine behavior.  But good single engine aerodynamics otherwise.

27 minutes ago, sd_flyer said:

What consequences of critical engine failure you expect? 

assuming a CW rotating pair or multi prop, the typical strong yawing and rolling moments due to factors such as:

- drag from the windmiling prop, until it get's feathered;

- assymetry of thrust enhanced in the starboard engine (P-factor of the starboard engine contributing even more to the asymmetry);

- asymmetry of lift from the wing are under the propwash from the starboard engine;

All of these, depending on your IAS/AoA will require prompt compensation, prompt and significant (sometimes, depending on the aircraft, IAS / AoA, full rudder towards the good engine - right rudder in this case.

Surely not the tame effects I observe in the default twins, and even in the Blackbird Simulations C130J...

20 minutes ago, jcomm said:

assuming a CW rotating pair or multi prop, the typical strong yawing and rolling moments due to factors such as:

- drag from the windmiling prop, until it get's feathered;

- assymetry of thrust enhanced in the starboard engine (P-factor of the starboard engine contributing even more to the asymmetry);

- asymmetry of lift from the wing are under the propwash from the starboard engine;

All of these, depending on your IAS/AoA will require prompt compensation, prompt and significant (sometimes, depending on the aircraft, IAS / AoA, full rudder towards the good engine - right rudder in this case.

Surely not the tame effects I observe in the default twins, and even in the Blackbird Simulations C130J...

The reason I ask because technically speaking what you describe is true for any engine that fails in multiengine aircraft. Critical engine importance is when it fails below Vmc speed  pilot looses control of the airplane (aka "Vmc roll") I have no idea what engine out procedures in C-130, but in small GA it "raise the dead and slip the ball". Basically your input controls has to be appropriate, but not necessarily full, to eliminate sideslip and drift

 

First you fly airplane than you decide whether you want to "fix" or "feather". "Fix" assume that you have time to determine nature of failure and try to restart it. "Father" when time dictated impending need to land asap. In "feather" part is most important thing is not shut down the "good" engine.

My guess four engine bird one engine failure not as dramatic like say in Baron. Although I believe two engines failure on both side would produce more dramatic effect !

 

I am a multi-engine instructor and have trained many pilots who successfully achieved their ratings.

The concept of the "critical" engine in my experience is overly dramatised because of the use of the term "critical". Yes, the theory is all correct i.e. P-factor etc. etc but in my experience in the twins I fly (mostly the BE95 Travelair, P68 Partenavia), a failure of the so-called "critical" engine results in no major discernible difference in handling compared to a failure of the non-critical engine.

I cannot speak for other types, but in the twins I teach in, this is the case.

A critical engine failure won't kill a pilot - failure to apply the correct drills and flying techniques will.

You can typically see a critical engine during a Vmc demo, where you'll run out of rudder authority at a few knots higher airspeed compared to a failure of a non-critical engine.  Certainly, the aircraft is flyable either way with proper handling.  And of course, a twin with counter rotating props like a duchess doesn't have a critical engine at all, no matter what fails.

It does seem, though, that the OP was referring more to general engine-out behavior.  I feel like, at least on good add ons, that's decently modeled.

5 hours ago, DavidP said:

The concept of the "critical" engine in my experience is overly dramatised because of the use of the term "critical". Yes, the theory is all correct i.e. P-factor etc. etc but in my experience in the twins I fly (mostly the BE95 Travelair, P68 Partenavia), a failure of the so-called "critical" engine results in no major discernible difference in handling compared to a failure of the non-critical engine.

I was going to post this exact same thing, but DavidP beat me to it. I am also an MEI (and former turboprop airline pilot) and I agree completely.

The failure of the "critical" engine does have, on paper, more of a detrimental effect than failure of the other engine, but in practice, the difference is small, and is usually overridden by things like wind gusts, turbulence, instrument tolerance, and pilot technique. 

 

Edited January 10Jan 10 by prolixindec

Thank you David and @prolixindec for your thoughts, but, what about the effects of failling the port, or starboard engine in the FS 2024 Baron 58, B350, Twin Otter, ... ? 

How do you, with your RL experience in multiprop, find the sim with it's CFD flight dynamics or not enabled, does it's job?

Having never had to deal with such a scenario IRL (gliders don't have even a single engine, unless they're SLG or SSG... and I don't have qualification to fly those...) I can only base my comparisons in the descriptions provided by RL twin prop pilots, friends of mine, accident reports, POHs and so on... 

I flew the Twin Otter in real life and it was a 100% completely enjoyable aircraft in every way. I loved every minute in it. I never had a real engine failure, but V1 cuts and other single engine maneuvers were a breeze. You needed a hard press on the rudder for sure, but climbing up and out on one engine was no problem at all. Thank you for allowing me to reminisce. 

Regarding simulated engine failures in MSFS -- I have no idea. I've never flown an aircraft within MSFS. I only use MSFS as a scenery generator for another sim.

I'll just say that single engine work with power requires significant rudder to to keep the wings level. (You need much less rudder if the good engine isn't developing much power, like in a descent or in the landing flare.) If your MSFS aircraft doesn't require lots of rudder for single-engine ops, then the flight model probably leaves something to be desired.

https://oddballpilot.com/2015/11/c-130-propeller-gearbox-failure-with-evan-smith/

Well, I was wrong 😕 ( again... ) regarding my comments on the Blackbird Simulations C130J ....

Truth is the many pilot notes / manual I have been reading pertain to older models of the C130, which were indeed prone to tricky handling under engine out scenarios...

This being said, I still don't found it plausible that the real C130J will handle the way this C130J for MSFS 2024 does with only #4 operational...

Regarding the C130J, Blackbird is actually modelling what is menstioned in the following explanation of the ATCS system:

_______________________________________________________________
This is one of the most interesting (and misunderstood) aspects of the C‑130J. The ATCS dramatically changes how the aircraft behaves after an engine failure, and it’s one of the reasons the J‑model feels so much more “civilized” than the H‑model in asymmetric conditions.

When an engine fails, the Automatic Thrust Control System immediately:
===============================================================

1. Reduces thrust on the opposite engine
This is the big one.
Instead of letting the good engine produce full torque (which would yaw the aircraft violently), ATCS pulls back the opposite engine to keep the aircraft controllable.

2. Balances torque between the remaining engines
It tries to maintain symmetrical thrust on each wing.
This means:

No sudden yaw spike

No “kick in the pants”

No need for immediate full rudder

3. Prevents over‑boosting the good engine
The FADEC won’t allow the pilot to accidentally command too much power on the remaining engine, which could worsen the asymmetric moment.

4. Keeps the aircraft inside safe controllability limits
The system is designed so that the aircraft remains flyable without extreme pilot inputs.

How much easier does this make the pilot’s life?
In short: massively easier.

On older C‑130 variants (E/H), an engine failure at high power meant:

Immediate, strong yaw

Large rudder input

Aileron to counter roll

Quick trimming

High workload during a critical moment

On the C‑130J, thanks to ATCS:

 Rudder input is dramatically reduced
You still need rudder — physics is physics — but it’s nowhere near the “stand on the pedal” situation of the older models.

 Roll tendency is much smaller
Because thrust is automatically balanced, the wing doesn’t drop aggressively.

 The aircraft stays controllable with modest inputs
Pilots often describe it as “surprisingly benign” for a four‑engine turboprop losing one engine.

 Workload is far lower
Instead of fighting the aircraft, the crew can focus on:

Identifying the failure

Securing the engine

Configuring for climb or return

 Training emphasis shifts
Instructors often say that asymmetric handling in the J is “almost too easy,” because the aircraft behaves so politely.

Edited January 12Jan 12 by jcomm