BlackLion213 Senior Member



Join Date: Mar 2015 Location: San Fransciso Bay Area Posts: 1,514

Quote: SMH Originally Posted by Looks great! Will it be PFM? PFM.



Long answer is: the model is an EFM meaning the flight model was developed outside of ED and in fact is a program that runs outside of DCS. It receives atmospheric and physical parameters (speed, AOA, etc) from DCS which is then fed into the Heatblur FM program. The program then crunches all the info and feeds forces to the rigid physics model inside of DCS.



I think a lot of people figure that FM development is a lot like a "mad libs" word game where you take some aircraft specifics and plug it into a framework that exists in DCS - that is true for SFMs. But PFMs/EFMs are clean sheet mathematical descriptions of the aerodynamic and physical forces that effect the airplane. So instead of a mad libs we are talking about a blank sheet of paper.....pretty intimidating.



In the case of the F-14, the FM was developed from NASA wind tunnel testing, NASA aerodynamic evaluation data, USN real world performance data (covering all aspects), USN documentation for handling/testing, USN docs for the AFCS system, flight control systems, USN weight and balance documentation (which proved to be quite important for replicating behavior), detailed engine documentation/dynamics modeling, etc, etc, etc.....a lot of stuff!



All of this information is then digested and converted to equations, coefficients, look-up tables, and all that stuff by the FM developer. The F-14 FM actually has 2 FM engineers/coders/developers. The lead is a joint PhD in engineering and computer science (Mechatronics) while the other's day job is as an FM developer for Level D simulators (private and light commercial jets).



Add to that, the FM has over a hundred hours of real F-14 pilot evaluation time resulting in many adjustments. We thought the FM was in pretty good shape a year ago when the pilots first stated giving feedback. Well a year later we have adjusted a lot of stuff! Things are actually quite different than they were back then (even without changing the core aero data from wind tunnels and other sources). FM development means a lot of very fine tuning that can have big effects. Without all the pilot input, things would actually feel pretty different - even though everything would still match the data. Aircraft feel is surprisingly dependent on small details.



I am happy to say that our pilot SMEs are quite happy with it, even as we adjust a few more details (like how much roll rate changes with wing sweep, as Cobra mentioned). One of our best SMEs (very detail oriented and he uses DCS habitually - he has made a huge contribution to the module!) recently described the FM as a "game changer" - so we are very happy with the depth and accuracy.



So like I said....long answer.



In summary: it's really good!



-Nick (Heatblur Tomcat tester) Short answer is: yes, but not called aLong answer is: the model is anmeaning the flight model was developed outside of ED and in fact is a program that runs outside of DCS. It receives atmospheric and physical parameters (speed, AOA, etc) from DCS which is then fed into the Heatblur FM program. The program then crunches all the info and feeds forces to the rigid physics model inside of DCS.I think a lot of people figure that FM development is a lot like a "mad libs" word game where you take some aircraft specifics and plug it into a framework that exists in DCS - that is true for SFMs. But PFMs/EFMs are clean sheet mathematical descriptions of the aerodynamic and physical forces that effect the airplane. So instead of a mad libs we are talking about a blank sheet of paper.....pretty intimidating.In the case of the F-14, the FM was developed from NASA wind tunnel testing, NASA aerodynamic evaluation data, USN real world performance data (covering all aspects), USN documentation for handling/testing, USN docs for the AFCS system, flight control systems, USN weight and balance documentation (which proved to be quite important for replicating behavior), detailed engine documentation/dynamics modeling, etc, etc, etc.....a lot of stuff!All of this information is then digested and converted to equations, coefficients, look-up tables, and all that stuff by the FM developer. The F-14 FM actually has 2 FM engineers/coders/developers. The lead is a joint PhD in engineering and computer science (Mechatronics) while the other's day job is as an FM developer for Level D simulators (private and light commercial jets).Add to that, the FM has over a hundred hours of real F-14 pilot evaluation time resulting in many adjustments. We thought the FM was in pretty good shape a year ago when the pilots first stated giving feedback. Well a year later we have adjusted a lot of stuff! Things are actually quite different than they were back then (even without changing the core aero data from wind tunnels and other sources). FM development means a lot of very fine tuning that can have big effects. Without all the pilot input, things would actually feel pretty different - even though everything would still match the data. Aircraft feel is surprisingly dependent on small details.I am happy to say that our pilot SMEs are quite happy with it, even as we adjust a few more details (like how much roll rate changes with wing sweep, as Cobra mentioned). One of our best SMEs (very detail oriented and he uses DCS habitually - he has made a huge contribution to the module!) recently described the FM as a "game changer" - so we are very happy with the depth and accuracy.So like I said....long answer.In summary: it's really good!-Nick (Heatblur Tomcat tester) Last edited by BlackLion213; 09-03-2018 at 03:36 AM .