CFM567b 18-22 Engine Sound & FDx

Ariane offers a new and unique approach to the simulated 'fitting' of engines to all of its aircraft.
To have gone to the lengths of recording real sounds from static and moving CFM engines only fulfilled one aspect to providing the simulation of the sound that engines make on a Boeing 737, But to realise the ambitous vision to do so with such prominent realism meant the development of an altogether new and different aspect, as featured in all aircraft packages, which would represent another leap forward in simulations software.

In flight simulation per se, the single most important aspect when it comes to the acccurate simulation of engines and their specification is how a programmed configuration logic is designed to relate to performance.
Handling is only one aspect of the design of a successful 'FDe' logic since performance must encompass a very wide range; long ramp burns, taxiing, take off, climb and cruise, descent and the final stages of the flight are al critical factors. Competent and single-use .air and .cfg files broadly specified to be used across the range of most simulations of this genre may be acceptable for the majority of simulation users but at Ariane, engine performance is placed as high on the agenda as attention to detail. Each and every engine is treated as an individual fitment as it would be from day one when CFM were given the specification by Boeing for a launch airline customer. Engine FDe modeling is therefore a critical area reserved for the professional programmer and engineer.

Ariane Engine Programmers have been working with CFM to develop and produce their own 'brand' of engine software for 7 years. Understanding how engine logic relates to simulator performance comes form experience and understanding. Ariane is fortunate to have access to a number of engineers as well as access to Boeing/Engine tabular data CBT but it is in the design of the engine software logic that the key to efficient performace is found.

Boeing offers a broad choice of engine types ranging from low and economic CFM567b18 to high-pass, powerful CFM567b27 (as fitted to Lauda Air's fleet). Engines need not necesarily follow a general rule relating to the 600-900 series. Because an aircraft such as the Boeing 737-600 is a short-range option does not necessarily mean that it will be fitted with a short-range engine. Engine requirement can vary across the board of the CFM567b engine specification due to airline requirement. Lauda's 600 Series are fitted with higher-powered CFM567b22 whereas Malev may be among the only airline to have specified lower power CFM567b18 for economic reasons. Engine power should play as important a part in software programming as it does with the real world counterpart and it is here that a new logic process we haev coined; 'FDx' comes into play.

Every simulation software program based in Microsoft Flight Simulator or developed outside the FS environment uses a two-part configuration called an 'FDe'. The 2-part FDe is responsible for governing the flight physics of a great many aircraft in the flight simulator virtual 'world' from the light GA Cessna to the larger, 'heavies' like the Boeing 747.
However, the FDe structure has been known to be fallible, not so much because the processing data is handled by the operation of the Microsoft Flight Simulator exe; 2-part FDe's that are tightly programmed are rare more than they are common; but because with only the limited data in the two parts there is insufficient data for more complex routines to be more fully realised (both more technologically and from an advanced point of view). It was with this criteria in mind that Ariane developed and created a new three-part system it calls FDx.

In 2004, when Ariane moved their development away from reliance on the old, two-part FDe flight physics model system and introduced the new factor to flight performance called: 'FDx' it was to open up a new sector in flight infidelity. It was FDx that gave Ariane Boeing 737 aircraft a unique ability that would affect the physical handling of the aircraft especially when being managed by the on-board FMS software. The 'x' factor in the FD configuration represents the culmination of the development of the new 3-part FDe. The third aspect of the envelope concentrates on tabular data that controls elements such as Mach vs. Speed; Mach vs. N1 and other important tabular logic areas. FDx not only affects performance. FDx directly and diametrically affects response to controls and reaction levels. One example is an element called 'Newton Logic' (TM Ariane Studios) whereupon at the point of engagement of thrust, real aircraft delay movement forward until the power-to-weight ratio factor is realised and the thrust has bypassed the point in time that the weight is overcome. The same is true of models using FDx where such delays can not only be seen but also measured via the built-in FDx variable. The variable is also adjustable and relates directly to the engine type fitted whereas a full passenger and cargo 600 with a CFM567b22 will reaxct differently to a full passenger and cargo loaded 600 with a CFM567b24 variant of engine. All airline options and packages offered as 'enhancement packs' include these very important calculations unlike most packages which only concentrate on 'painting' the outside of the aircraft!.
Note: FDx is one of the many factors that separates Ariane Developed Boeing 737 aircraft from all other simulations. Only Ariane Boeing 737 aircraft are designed and developed to this very high level of quality and perfection.