Sideslips...?

[Anatoli-Kagari9]

See in this other thread please:

 

http://forums.eagle.ru/showthread.php?p=1614504#post1614504

 

And please watch this other track, with a long approach in sideslip...

 

BTW, as a RL glider pilot I do know of many gliders without sufficient aileron authority to sustain a sideslip - the Grob 103 Twin I usually fly is a good example... If I enter a sideslip during final app, and use full rudder deflection, then I will run out of opposite aileron to sideslip in the right track towards the rw.

sideslip2.trk

Edited November 25, 2012 by jcomm

[-Mop-]

i once sat in a glider... the pilot performed a slip like you described to lose height and speed in final approach, not to shoot over the runway into the next haypile...

 

i tried this ingame... a this works very well...

 

was this your question?

[Anatoli-Kagari9]

Mop,

 

my question had to do with the fact that the Manual mentions sideslips are not possible to maintain in the P-51. I still find less rudder authority then I expected, and way too much aileron authority, but then again, I never flew a P-51 :-/

[Echo38]

I wondered about this myself, Jcomm, when I read the manual, but I forgot to add it to my list of questions to ask. I rather suspect--and this is an uneducated guess, but--I almost think that it's the manual that's wrong in this regard, rather than the simulation.

[Ala13_ManOWar]

Well, manual says it can't be maintained, not it can't be done :). I also hadn't flown a real P-51 but in some common general aviation aircraft you also can't maintain a sideslip for a long time. When it can't be maintained I usually make sideslips changing one side to other (RL I mean), so you can keep runway track when she wants to go out of track because lack of controls. Have you try in DCS not if you can do it, but if you can maintain it for a long way or may be you have to change on side to other?

 

S!

[Anatoli-Kagari9]

Yes,

 

I tried all combinations, changing side, various flight configurations as well. The "problem" for me is - but I am not saying this is not realistic because I do not make the slightest idea about how the real thing behaves:

 

1) You have insufficient rudder authority

2) You have excessive aileron authority, so...

 

To keep it on a track with the centerline of your rw you can't use much aileron, otherwise it will bank way too much. OTOH the rudder authority is so weak that your sideslip angle is shallow ((haven't tested with crosswinds because I do not yet know how to change weather parameters or create a simple mission in DCS World :-(... ))

 

Well, manual says it can't be maintained, not it can't be done :). I also hadn't flown a real P-51 but in some common general aviation aircraft you also can't maintain a sideslip for a long time. When it can't be maintained I usually make sideslips changing one side to other (RL I mean), so you can keep runway track when she wants to go out of track because lack of controls. Have you try in DCS not if you can do it, but if you can maintain it for a long way or may be you have to change on side to other?

 

S!

[Yo-Yo]

Manuals can be wrong. It's a proven fact. For example, one of manuals tells that glide rate for the Mustang with dead engine is 15. It's a BS (no Black Shark, of course :)). Real P-51 has approximately 10:1 with low rpm setting, 7:1 at high and 4..5:1 if the prop is not rotating.

I know how 15 was born... somebody from the department of technical documentation had heard about P-51 max L/D = 15 and remembered his college lectures.

There are at least two test reports - one for XP-51 (P-51A) with even less effective ailerons than P-51B and D and the second - for P-51D where exact charts of steady sideslips are presented.

I asked pilots of real P-51 about it and they said that there is no problem to maintain it.

 

Anyway, the plane can be landed up to 20-25 knots of crosswind. Taildraggers must be oriented along the airstrip before touchdown to avoid ground loop, so the approach must be done in steady straight sideslip. If the plane can not maintain it how will it land?

Edited November 27, 2012 by Yo-Yo

[Anatoli-Kagari9]

Yo-Yo,

 

I'm trying to learn so many things about this beautiful pony that I couldn't even imagine were that way that I already find this to be one of my best investments ever in flight simulation :-)

 

Anyway, I do agree with some reports of weird behaviours from various users, some of them RL pilots (engined / prop airplane pilots, not like me...) and I look forward for further enhancements!

 

All of the best from a very happy portuguese user :-))))

 

Manuals can be wrong. It's a proven fact. For example, one of manuals tells that glide rate for the Mustang with dead engine is 15. It's a BS (no Black Shark, of course :)). Real P-51 has approximately 10:1 with low rpm setting, 7:1 at high and 4..5:1 if the prop is not rotating.

I know how 15 was born... somebody from the department of technical documentation had heard about P-51 max L/D = 15 and remembered his college lectures.

There are at least two test reports - one for XP-51 (P-51A) with even less effective ailerons than P-51B and D and the second - for P-51D where exact charts of steady sideslips are presented.

I asked pilots of real P-51 about it and they said that there is no problem to maintain it.

 

Anyway, the plane can be landed up to 20-25 knots of crosswind. Taildraggers must be oriented along the airstrip before touchdown to avoid ground loop, so the approach must be done in steady straight sideslip. If the plane can not maintain it how will it land?

Edited November 27, 2012 by jcomm

[Chill31]

Manuals can be wrong. It's a proven fact. For example, one of manuals tells that glide rate for the Mustang with dead engine is 15. It's a BS (no Black Shark, of course :)). Real P-51 has approximately 10:1 with low rpm setting, 7:1 at high and 4..5:1 if the prop is not rotating.

 

Yo-Yo, it has been my experience that the rotating propeller in an engine out glide situation is more drag than a stationary propeller. In that case, the L/D is higher for the stopped prop. The data posted shows a lower L/D for a stopped prop. Just wondering if its typo or actual data.

 

Thanks

Chill

[Yo-Yo]

Yo-Yo, it has been my experience that the rotating propeller in an engine out glide situation is more drag than a stationary propeller. In that case, the L/D is higher for the stopped prop. The data posted shows a lower L/D for a stopped prop. Just wondering if its typo or actual data.

 

Thanks

Chill

 

It depends on various factors like prop pitch, the ratio of total blades area to disk area, and gliding speed. It can be very different for different types of planes. For Mustang it is as I described.