Pitch Up Moment

[Zooker]

I just returned to tinkering with the 109 and there have been some significant patches in the interim. I've noticed a huge pitch up moment from the aircraft at cruise speeds. The nose down trim, barely counteracts the pitch up moment. Is anyone else experiencing this? Is this correct behavior?

[gavagai]

Have a read, enjoy!

http://forums.eagle.ru/showthread.php?t=135453

[5tuka]

Just my 2cent (I know the old discussion but I have a different, more precise theory about this behaviour). The pitch up effect even with full downtrim only occurs at certain angle of attacks. If you take off with nose heavy trim for example without moving the stick the K4 will first show a heavy pitch up tendency (keeps pitching up until speed drops). If you push it into horizontal flight or lower the nose will start to drop though. So trim does seem to work properly, however the effects are only noticeably at low AoA.

 

I tested this at various speeds, power on, power off. Always the same result to a varying strong extent.

 

The only reasonable explaination to me for this lies in the lift curve calculation for the airfoil and/or stabilizer.

 

I remember the 190 being very tailheavy in beta which forutnately was fixed and made it a pleasently stable aircraft to fly so I'm confident the K4 will gain it's facelift to become a stable aircraft as well. But the way it is now it shows very unstable behaviour at positive AoAs which I have not seen documented anywhere.

Edited December 2, 2015 by 5tuka

[Ala13_ManOWar]

I've noticed a huge pitch up moment from the aircraft at cruise speeds. The nose down trim, barely counteracts the pitch up moment. Is anyone else experiencing this? Is this correct behavior?

The thing is that can't be correct, I mean what you say. Not the 109 but any aircraft can have that pitch up moment in certain conditions, and 109 isn't any different. But 109 doesn't have that behaviour at cruise settings, it does have it out of cruise settings, usually while you're using high or very high ATA settings. Cruising in 109 is quite fine, but that's using cruise settings, some 1.15ATA for instance, 1.2 as much or even lower settings until 0.9. If you want it to cruise 1.3ATA or higher hands off that's just impossible mainly due to torque effect even at low speeds. It's being kinda war around here about that, and finally yes, it looks like it's correct. Bear in mind you're flying a very small fighter with 1800HP in front of you.

 

S!

[Crumpp]

I remember the 190 being very tailheavy in beta

 

That is what I have been experiencing in the Dora since the last update.

[Anatoli-Kagari9]

I really have to test it tonight, so I hope...

 

Will run the tests in the Dora in 1.5.1 and 2.0 over Nevada, both offline and online - don't know if there are already any online servers available for Alfa 2.0 of EDGE and the Nevada Terrain ?

 

I will try to post my findings ASAP.

 

Have been dogfighting in the K4 in 1.5.1. The moment we get into higher AoAs things become a bit out of control sometimes, particularly if you're in the middle of a dogfight.

[NineLine]

This has been discussed before. No bug.