The config file shows max rpm of 2700. Mine will only wind up to 2250. I have some grass strips that I can't take off of because of that. Is there a way to change this? Don

How about it Bill? If it can't be done just tell me it can't. PleaseDon

If you have a yoke/joystick with a prop pitch lever, push it fully forward...Otherwise, use the keyboard commands to set prop pitch fully forward...

I DO have a yoke and it is fully forward. I also manually tried pushing the prop lever with the mouse. The rpm's will not go beyond 2250. I wish you would try it and let me know your results.Okay I tried again and found that once I am in the air the rpm's will max out, but that don't help for takeoff. T;hat is when it is needed.Don

Try loading the FSX default flight and then change the aircraft to the Navion and see if that fixes the problem.

Don,I don't know much about the Navion, but based only on the specs supplied in the config files, and a few minutes testing, I found your report is correct and the reason why. Full rated RPM for take-off can't be achieved, as you say, and I don't think that's typical for the engine/prop combination specified. I found that the engine makes much less than the rated 285 bhp it should make ... in context, the power available (i.e.much less than the specified 285) isn't enough to allow the engine/prop combination as specified to achieve take-off rpm. Low rpm = low HP. In flight, the engine/prop combination can reach full RPM but the power output at full power remains below the specified 285. I hope this explanation is seen as constructive and that the self-explanatory images below are helpful ...http://www.fsd-international.com/temp/misc/navion1.jpghttp://www.fsd-international.com/temp/misc/navion2.jpgThis is a nice freeware project, congrats to all......Best Regards,http://www.fsd-international.com/team/Steve_signature.gif

>This is a nice freeware project, congrats to all.Thanks for chiming in, Steve. I didn't write the FDE for the Navion, so I really don't know why it's behaving this way.I've never had any problems with taking off though, even from very short field configuration (full flaps, pitch trim +5), so I've never really paid much attention to the PROP RPM.Sure enough though, ~2250 is the best I can get, even after a few seconds for the engine to produce as much as it's going to.I do notice that changing the power_scalar helps quite a lot:power_scalar = 1.2 //will produce 2670 after ~6 seconds

Hi Bill,No problem, happy to contribute. I found using 6.9 as the prop diameter with a power scalar of 1.225 will give you 286 hp at 2700 full power at sea level. There's no loss of prop rpm control at speed or altitude with the reduced diameter and increased HP. The caveat is that I don't have any specs for this a/c and I don't know what the minimum diameter limit is for this prop . These HP & prop tweaks seem to hold from SL to critical altitude, but someone may want to look at the drag values now that the HP is up where it should be.H.T.H.Best regards,http://www.fsd-international.com/team/Steve_signature.gif

Thanks to everybody for suggestions. Now I can at least try a few things. I had no idea before what to try. I really like this plane but I have a field that I frequent a lot (grass strip) and I can't take off from there with the navion.Don

Here's something else that might be worth a try too Don,Click on the 'Fuel And Payload' button on the top left of the aircraft preview window. Try re-setting your fuel quantity to say; 60% and in the 'Payload' section, just have yourself weighing in at say 10 stone = 140 pounds, no co-pilot = 0, no passengers = 0 and baggage at 50 pounds = nice CoG.One notch 'UP' of pitch and one notch 'Down' of flaps, brakes on until 2000 RPM is reached, brakes off and she will take you up nicely.This little aeroplane of Bills' is a beautiful model and is my favourite for bush flying here in Queensland, it never fails on the grass runway at Caboolture (you need Ozx addon for that airfield) where I park it up.DaveVH-DBWBrisbaneAUSTRALIA

Hi Dave. I didn't really want to mess with the weight limits so I set the prop at 6.9 and the power scaler at 1.225 (thanks Steve) and the problem is solved. Rpm's max out on start and I am in the air in very short order. Thanks again to everybody that helped.Don

>This little aeroplane of Bills' is a beautiful model and is my>favourite for bush flying here in Queensland, it never fails>on the grass runway at Caboolture (you need Ozx addon for that>airfield) where I park it up.Thanks for the kind words, Dave. But, let's not forget to give credit to Richie, without whom this project wouldn't have existed at all...I just added some finishing touches on the model's exterior, added the VC panel, the liveries, and the panel system to the project. The model itself though is mostly Richie's work.

I think I left Richie out too when I was thanking people for this plane. I didn't mean to do that so this can be considered a correction. Thanks Richie and BillDon

:-eek Yes, my apologies to Richie as well Don and Bill, for omitting to mention him from this awesome joint project. :-beerchug