SR22 Power settings innaccurate

[richieflyus]

I've been testing out the Sr22 in the circuit as per the Cirrus Flight Ops Manual and I think the performance is a little out. The feel of the aircraft is great, no complaints there! 

According to the FOM, the SR22 should be 30% Power / 15" MP Downwind for 100KIAS. I'm finding it needs more like 44% power to maintain 100KIAS in ISA standard conditions, no wind.

Beginning the descent at the mid-downwind point should be 15% Power and 50% flaps, trim for 100KIAS - with anything other than a very rapid rate of descent you cannot maintain anything like 100kts. It drops to about 78. Adding 100% flaps thus reduces way beyond the 90kts indicated in the FOM for base leg, 100% flaps and still 15% power. These two stages need more like 25-30% power or more to maintain the required airspeed. 

Final for the SR22 should be 15% or as required to maintain 80KIAS. This again needs more power to stay near 80KIAS. 

Interestingly the SR22 Turbo gives 50% power for Downwind and 25% for Abeam and Base, which is getting closer to what I'm seeing in the non-turbo version of the Torquesim SR22. 

Image attached

Edited September 25, 2020 by richieflyus

[John T.]

Agree with you.  Power settings are off relative to the real life plane.

[Coop]

There are three different things at play with this:

1. There are some slight issues with the current flap behavior, which can affect speed behaviors.
2. There are ranges to these, its not an exact % for each individual aircraft and changes with weight and balance.
3. There are some issues that X-Plane is working on that affects L/D behavior. Experimental flight model should help in this regard.

[John T.]

Awesome thanks.  Looking forward to the updates!

[richieflyus]

Awesome thanks for another great response.

Appreciate there are subtle variations from model model, for example my friends real world SR20 normally needs about 2-4% more power setting than the book, but that's a lot less than the difference I'm having to apply in the Torquesim right now Vs the book  

I should also mentioned I was flying half tanks and just the pilot, so no significant weight issues. 

That makes sense ref the flaps, the flaps on the SR's produce a big change, but perhaps not quite as big as they currently do on the Torquesim.

looking forward to the refinements! 

[Aleksandar]

I didn't really notice the power issue (I fly by speed), but definitely looking for a bit of refinement to the effect of flaps....seems quite agressive, such that I takeoff with full flaps, and don't drop flaps until I'm below 100kts on arrival.