Paul Eirik

I have the same problem, but don't know how to fix it 😞

Tell me if you find any solutions.

On ‎5‎/‎7‎/‎2017 at 7:23 PM, whamil77 said:

To your first point....that is correct.  At 1550 ft-lb and 2200 RPM no mechanical limit has been reached therefore, no failure.

To the second point, it's fine to use a failure simulation to get pilots to respect engine limits.  But in this case it is arbitrary and inaccurate.  No limit has been exceeded, but the engine fails.  May as well roll some dice and do a Monte Carlo or better yet, set up a random failure in P3D settings.

Your third point....in the simulation if you select 2000 RPM and any torque setting above 1484 ft-lb torque (up to 1628 ft-lbs is perfectly legitimate in the POH), the left engine will fail in 2 minutes and the right will fail one minute later.  Again, arbitrary and inaccurate.  The simulation does not reset the torque limit based on RPM, nor should it.  It should have done what I did and set the torque limit to the actual mechanical limit.  The mechanical torque limit is 1628 fl-lbs.  That's why a 2000 RPM and 1628 ft-lb power setting is authorized and documented in the POH. 

There are three limits in play.

1.  Horsepower limit - An aerodynamic limit based on the airplanes ability to remain controllable with a critical engine failure at Vmc.  In this airplane the limit is 620 SHP.  That equates to any combination of torque and RPM that makes 620 SHP as long as the mechanical torque limit (1628) is not exceeded and the prop RPM limit (2200) is not exceeded (1484 ft-lb @ 2200 RPM up to 1628 ft-lb @ 2000 RPM).  These same engines/gearboxes were limited to 550 SHP in the King Air E90 due only to aerodynamic considerations (1315 ft-lb @ 2200 RPM up to 1450 @ 2000 RPM).  Any torque limit that is below the gearbox mechanical torque limit is a aerodynamic Vmc limit, not a mechanical limit.  Cheating on Vmc does not cause engine failures.  Cheating on Vmc causes control problems if an engine fails above the power limit, but it does not cause an engine to fail.  

2.  Prop RPM limit - Mechanical, metallurgical, and tip-speed limit.  2200 RPM for this airplane.

3.  Gearbox torque limit - Heat and metallurgical limits.  1628 ft-lbs for the PT6A-28. 

Setting the torque limit to 1628 ft-lbs in the gauge update makes the simulation accurate.  Users will experience fewer engine failures but the simulation will be accurate.  Users wanting to experience random engine failures not associated with exceeding the aircraft's limitations can select that in the settings tab of the simulator I believe.   

 

Hi, I am experiencing the engine failure without exceeding any limits. All gauges is in the green zone. I usually cruise with 1900-2000 RPM and 90-100% throttle, which result a Torque about 1050 ft-lbs at FL230. I have tried to increase the limit in the GAUGE_UPDATE_DIG.xml file, but I don't know how to make a cabinet file or overwrite the file. 

Do you have any suggestions to avoid the engines failing at each flight?

I'm flying this aircraft in a world trip, so it would be helpful to have a aircraft without any risk of engine failure.

I appreciate all answers I can get :-)