Turboprop Flight Simulator Beta
Sharon Harris
Is beta mode planned to be added natively to turboprop engines? I heard Seb
mentioning it before Sim Update 4, but no news since. Currently, putting the
power lever on reverse immediately sets the propeller pitch to full reverse
and starts producing negative thrust. What happens in reality is that when you
put the power lever below idle in a turboprop it controls propeller pitch:
The result of this is that when going in the reverse/beta range, the propeller
initially produces less and less thrust from idle, until reaching the beta
limit. Then, it goes into full negative pitch and starts producing
reverse/negative thrust. Required cfg values would be:
To add to this, moving between beta and normal modes is pretty much instant.
Currently from the reverse to forward setting on the caravan for example takes
at least 5 seconds to change into forward thrust again. Turboprops can taxi
for example using forward/beta/slight reverse thrust without any brake input
to control their taxi speed.
@FlyingRaccoon, Any news on this, I am now working on a project that uses the
Beta range as Alex is describing, I just want to know if it is worth waiting
for the Asobo implementation or is better for me to code my own solution at
this time. Best, Raul
Hey guys I am not accustomed to a turbo prop. How can you taxi the Otter without it wanting to do 50 on the taxiway? Should you feather the props and add a little throttle? What's the method? I had the same issue with the Caravan years ago in previous sims. I have spent most of my time in radial engines or jets.
I use a little power to overcome inertia, then find it will taxy nicely at idle power. If too fast, a touch on the brake or beta power but using a throttle detent for beta (which is a switch, rather than an axis) means that it can only be engaged for short periods without stopping the a/c.
I use a little power to overcome inertia, then find it will taxy nicely at idle power. If too fast, a touch on the brake or beta power but using a throttle detent for beta (which is a switch, rather than an axis) means that it can only be engaged for short periods.
Yea that is what I do now.. I just find it excessively fast. You get it going by just barely inching the throttle and then it wants to just keep increasing speed up, up and up. Even after you have cut the throttle. If you engage reversers it stops it but as soon as you turn them off its back to the races again.. I find myself just riding the brake, which would be bad practice in real life obviously.
In most Turbo-Props you are using the BETA mode for taxiing, which is usually not managed by prop levers (several Turbo-Props do not even have a prop lever) but with the throttle. I always configure my throttle settings in X-Plane so that the first 10% are for Reverse thrust which is also mostly managed by the throttle setting in real life, another 15-20% are for the BETA range and only the remaining 70-75% are for normal operation mode. These values may need adjusting for your individual throttle/aircraft combination but as a general rule of thumb these values work well.
By using these throttle settings in XP11 I can vary the taxi speed from complete stop till 30+ knots without having to use the brakes, I can actually even slow down by adjusting the throttle, no matter whether the plane is at MTOW or extremely light.
I'm not sure how to implement these setting in FS2020 because I stopped using it a while ago but if I remember correctly, it was not a problem at all...
has anyone else managed to calibrate the throttle such that 75% is normal range and 25% Beta on the H/C Bravo? That would remove the need to use the detent for Beta which is just a switch and doesn't produce an 'axis-like' effect....
Unfortunately, MSFS doesn't have this ability to set up separate detents for beta range and reverse. Hopefully it will come in the future. In the meantime, the developer has to provide a throttle calibration function. This is done for example in the FBW A320 neo for reverse, climb and flex detents.
Well yes and that is what I have done with my TQ6 throttle quadrant as well. But you really only get one detent rather than the two that are required. You sort of get the right effect but it is better with the X-Plane Twotter where you have separate beta and reverse ranges. Also, with the current turboprop modelling in msfs I don't think the props are actually feathering the way they do in the real world and they are just simulating the increased drag. But hopefully that will come with a future sim update. Like the OP, I also find taxiing a bit of a challenge and it is hard to find that point in the range where the plane is neither speeding up or slowing down.
That's why in good part you shouldn't notice any Fuel Flow variation as you adjust Prop RPM at a constant altitude and throttle + condition setting. I don't know if this has been corrected in the core turboprop simulation of MSFS, but it was plain wrong throughout the various versions of MS FS and P3D.
Initially your limiting parameter as you climb away will be Torque. However at roughly 18k -20k feet the limiting parameter will be turbine temp /ITT so you will now ascend with a constant decrease in TRQ and subsequently fuel flow. Those two form the basic operational limitation relationship.
RPM is managed by altering prop pitch (blue lever). On takeoff you have a very fine pitch (lever fully forward), makes is easy for the engine to rotate the prop (think of it as 1st gear on your bike). As you climb you reduce RPM (TRQ will now increase since prop blade takes a larger "bite" of the air). In cruise you will typically reduce RPM even further. It can act both as a climb and cruise propeller. Best of both worlds.
Thanks. But the Kodiak Manual seems to assume that RPM is always at 2200 and you adjust torque for take off or cruise based on temp and altitude. I don't see any recommended settings for RPM - other than 2200-2000. All the tables provide torque values. So should I just keep the blue lever pegged to the firewall and adjusting for recommended torque with the black lever then?
Beta is a small range of the power levers (which normally regulates fuel flow into the turbine) where you directly control pitch angle. Used when taxiing (instead of applying brakes) and also for reversing.
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