Milviz C310R Official Thread

RPM is only ONE of the parameters here, and the least important in this case, and you seem to be very focused on this without understanding the full physics, which is fully described in the video above. What’s most important is current speed of the aircraft (slow when you’re on final, with high drag to boot), and therefore speed of air approaching the blade, and blade angle. At slow speed, fine pitch is where you want to be to get out of any situation quickly because it’s going to give you the most thrust.

The most power. Needs the time function to make it work.

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No. You’re still not taking into account time.

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No. The most thrust is at 2300 RPM, all other parameters equal (in your low speed scenario).
The (sim) plane flies fastest and accelerates the fastest in that RPM setting.
It’s simple physics, it’s the sweet spot where at that given speed the most energy is transferred into forward momentum.

Wrong modeling of this in the sim not withstanding, I have no real 310 to compare.

There might be still other reasons than max thrust/ acceleration to go to max RPM?

Isn’t (engine) power a straw man here? What use has engine power, if it’s not efficiently transmitted from blade to air?

Did you watch the video?

Dude, stop. No. I cannot overstress how wrong you are because you omitting a critical factor, time, or more specifically, time to climb (rate of climb) to a safe altitude.

Your model assumes a best forward speed attained after time x, which is not addressing time climbing, the critical factor.

Rate of climb is dependent on power. Full stop.

I guarantee that, everything else normalized, two aircraft going missed approach, one at high RPM, one at cruise RPM, the one at high RPM will get to a safe altitude (or pattern altitude, etc) first.

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No, it’s not a straw man. I’ve explained the basic physics to you several times and you’re refusing to listen. Power has a time component. Rate of climb is dependent on that time component.

We’ve established that torque x RPM = power. You’re basically throwing out a word (“power”) without understanding the definition of the word and applying the necessary physics.

I’m not questioning that. I‘m questioning that ENGINE power DIRECTLY translates to forward acceleration (which then through lift results in a climb rate)

I‘ll do some test flying.
Still this plane accelerates best at 2300 RPM and speed is kinetic energy.

A aircraft’s ability to perform a sustained climb is a function of excess thrust (angle) or excess power (rate). This is proven fact. This is what you need to look up so you can acknowledge it.

Zoom climbs (trading forward energy for altitude) are the strawman here because we don’t do zoom climbs in this regime of flight. Loading up the wing and decreasing airspeed while slow and dirty is almost a guaranteed stall.

Once we’re at a safe altitude (and this altitude can vary), we can relax the engine a bit for noise abatement, engine life, forward-speed efficiency, etc. but in those first several hundred feet of takeoff or go-around altitude (which is what we’re discussing) you want best power.

Not “power” as in some nebulous definition of output, but the physical definition of energy transfer (work) over time.

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They don’t publish updates for products until Thursdays to my knowledge. We don’t have a means to be able to determine when it will be released. I will make a post here when I see that it is available. :slight_smile:
kind regards,

Blackbird team

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Hey there. I am not a RW pilot, watched the video once and even I understand it. It’s simple, really.

A propeller blade is basically a wing. How can a wing move fast? Well its angle of attack needs to be minimal. When an aircraft is stationary or moves slowly (e.g. takeoff and landing), prop RPM can be high AND therefore produce a lot of thrust because the angle at which the air hits the prop is near 0°.

Set a high pitch and things look a lot different, higher AOA → less thrust because there is not enough air coming from the front. Move faster, AOA becomes less and you gain better thrust. Therefore you should always stay at full RPM on the approach because you are approaching the runway SLOW, not FAST.

Back on topic, I have seen a video of a C310Q where the fuel gauge needles wobble up and down during taxi. Thought that might be a nice little touch to the plane in the sim :grin: even though it may not receive an update again.

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Be sure that if they have not published the update yet, it is for some reason that something is not working perfectly.
It’s normal to hear that it’s better to buy directly from the developer, some times cheaper, faster… but, so far, I haven’t had the slightest problem with the market place.
For some unknown reason, the developers have introduced a system of trying to guess where you have your system installed, instead of asking the client where to install it: the marketplace knows exactly where to install it, in a few minutes, and without further complications or the need to do a previous course.
Wait a bit, when they publish the update it will be secure enough.

I’m remiss that we’ve kind of thrown the baby out with the bathwater in not mentioning that in a constant-speed prop system, the governor is doing its “magic” in order to change the blade angle to balance torque and thrust to achieve the desired RPM setting. So it’s not as if there isn’t a significant bite being taken out of the air at fine pitch settings. But that pitch/bite will vary with forward airspeed (and the commensurate change in angle of attack).

By forcing the RPM lower, the blade pitch can be overly coarse to the point they’re (well, the tips at least, depending on blade twist) actually stalling at lower forward speeds.

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after some test flights, this seems not to be the case with the C310R here. Don’t kill the messenger. :wink:

two comparisons.
1.) takeoff, no flaps, full MP, mixture rich. Start the stopwatch at break release, rotate at 90kt, gear up, pitch to 120 kt climb speed, stop watch when climbing through 2000 ft.

a) RPM 2300
b) RPM full (2700)

no significant differences for both scenarios. reaching 2000’ between 92 to 94 seconds after breaks release.

2.) cruising at 200’ above sea level @ 100kt, flaps 15°, RPM 2400, simulating go around, sudden full MP, starting clock watch with pitching up and maintaining 110 kt in the climb, stopping watch when climbing through 2000’

a) RPM remains 2400
b) RPM also full forward simultaneously with MP full forward

no significant differences for both scenarios. reaching 2000’ between 80 to 82 seconds after pitching up.

Fuel flow and engine stress significantly higher for the max RPM setting.
No significant difference in performance. Reaching altitude at practically the same time.

Just saying.
It seems change to full RPM is not really important for a go around and best climb performance, if you are cruising or descending with at least 2300 RPM.
At least with this sim 310R.

None of this matters. It a sim doing sim things. If you find that flying with the engines completely off in the sim gives you better speed, then I would highly recommend doing so.

Our conversation was based on real-world scenarios that may or may not apply to the sim. But the questions you raised, while good questions, at some point needed a hard “no” because it’s simply not the way it works IRL and shouldn’t work in the sim.

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let’s be serious…
Try it yourself.
I wonder how it would work differently IRL. Not so nice, it this C310R is modelled so unrealistically.
Isn’t the reason for full RPM also another than just best climb performance?

I don’t even know how to respond to this continued line of argument. I hold a complex endorsement. I actually have an extensive education in this and plenty of experience flying.

You’re basically asking me to disprove what’s already been proven over and over to the point it’s common knowledge.

In the sim, you’re free to do it however you want to get the best results. It’s not using real physics, it’s simulating them. So the outcome is moot. The problem I have is that the argument you’re making is based on real-world principles that the sim doesn’t touch - it approximates and simulates, but it doesn’t actually have a governor, oil moving, flyweights, speeder springs, and blades swinging through and interacting with the air. Maybe someday we’ll get that kind of fidelity.

But the discussion has been based in real-world application, and I don’t want the community to get the wrong idea from an adamant argument that sounds like it’s correct, but omits key details, thus making it, simply, wrong.

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Go-arounds can happen at less than approach speed and can happen even after wheels are on the ground. Depending on the situation, it might be better to use best angle of climb especially if landing long with obstructions at the end. In that scenario, does lower RPM still make sense?

the video basically says. at ZERO kt (starting the take off roll) max fine pitch (@full RPM) is the most efficient state of the propellor blades to produce forward acceleration.
Now at rotation/take off speed, which is more like in the middle between max cruise speed and zero kt, the most efficient blade angle to produce forward momentum is LESS than max fine pitch.

It’s what I have said all along here?

Same goes for go around speeds. they are not zero kt.