Category: Prepar3D V1-4 - Aircraft Repaints, Textures and Modifications
Cessna 421 advanced physics

File Description:
C421C advanced physics Modification for the Alabeo C421 C Golden Eagle Version: tested for P3DV4; should work also with P3DV5 (and probably FSX) 1. Why I developed the advanced physics version I was asked via this forum, via PMs and also by e-mails to provide a modified version of the Alabeo C421C which can be used for serious multi-engine training. It should have accurate type specific performance for both AEO (all engine operative) and OEI (one engine inoperative), the latter for either a windmilling prop at various speeds and for a feathered engine. Feathering should work as realistic as possible. Thus, I developed an advanced physics version of the Alabeo C421C. It shows realistic physics for negative thrust (prop drives engine). This is necessary for OEI training and more realistic idle power simulation. 2. Modified files Modification includes “c421.air” and “aircraft.cfg” files. Data is based on real world Cessna 421C, N100L, 421C-0313. Aircraft data, equipment list, checklist and other documents for N100L, as well as some images of C421C, registration N100L, can be found here, too. Unfortunately, due to copyrights, I can’t upload the full files and can’t provide the AFM and other copyright protected documents. 3. How to install To update “c421.air”: - Copy the original Alabeo C421 to another aircraft folder, e.g. “C421C advanced physics”. - Use AirEd (freeware) and open the original “c421.air”. Open AirEd a second time and open “modifications advanced physics c421.air”. Copy the modified tables 511 and 512 to the original .air file (right click in modification file -> copy -> right click on original file -> replace from clipboard) To update “aircraft.cfg”: Just copy the modifications to the corresponding position in the original file. 4. Legend of modifications Modifications in aircraft.cfg: - Basic Empty Mass (actual mass for N100L 5,154 lbs inserted; most C421C are more heavy, ours is on diet) - correct basic data for engines + props - engine friction included (necessary for all negative thrust scenarios) - flaps lift + drag scalar adjusted (split flaps) - 2 vacuum pumps - VMO = 151 KIAS; VNE= 240 KIAS - cabin: max. differential pressure: 5.0 psi Modifications in c421.air: - implemented negative thrust scenarios in prop thrust and efficiency curves (tables 511 + 512); adjusted thrust curves for high TAS at high ALT 5. Side effects of modifications: - more realistic engine starting: starting the engine needs the throttle to be 2 cm above idle (see checklist) for the first 15 seconds - if you start the engine and don’t retard the prop to medium RPMs immediately, you will overstress engine and prop. So be careful when doing an air start, you might lose the prop and the aircraft. (In the real aircraft, these effects are less severe, but you have to avoid high RPMs until the engine is warmed up and have to avoid rapid change of RPM.) 6. Additional Notes: - Basic aircraft data as published by the manufacturer, like range and service ceilings, especially OEI, are based on MTOM. - The use of high payloads close to MTOM and higher ambient temperatures are making for a more challenging OEI training. - In the sim, climb power is too low compared to full power (about 65 % instead of 75 %). I have to find a way to adjust that. - I have buttons for engine failure under the mixture (see images) - Seat Position is, like in many Aircraft, higher than as per Default by the sim. For the C421C and me being 5 ft 7 in, that's about 7 clicks arrow up.