Slipping the 109

[andyw248]

Found myself coming in for an approach way too high today, so I used a forward slip to get the 109 down for the landing. Works perfectly  .

 

Since I had the recorder running I made a little video of it: http://youtu.be/M4KMCCPvyA0.

[6./ZG26_5tuka]

Watch https://www.youtube.com/watch?v=3vXtCEL2WQs at 1:30. This is how an effective an real sideslip should look like, not the wonky hozizontal-flight attitude we keep getting in BoS due to rudder roll momentum overmodeling.

 

Pls don't take this offensive, your landing was nice, but the modeling of sideslips is completely off in BoS (it only works somewhat with the Lagg-3 and Yak).

 

Edit: Just saw you referred to forward slip. Well basicly we are (actually more or less) limited to forward slips in this sim which is a real pain. Hopefully they'll refurbish their rudder / prop wash mechanics to make this basic aircraft manouvre possible (atm BoS and RoF are the only sims I know  where it's impossible to accomplish a clean sideslip).

Edited January 11, 2015 by Stab/JG26_5tuka

[BlackDevil]

Watch

at 1:30. This is how an effective an real sideslip should look like, not the wonky hozizontal-flight attitude we keep getting in BoS due to rudder roll momentum overmodeling.

 

Allthough I think as well that the rudder induced roll is overmodelled, your video shows less than is possible with the BoS 109.

[StG2_Manfred]

Allthough I think as well that the rudder induced roll is overmodelled, your video shows less than is possible with the BoS 109.

Video?!

[BlitzPig_EL]

I was finishing a campaign mission last night, and a couple 109s followed my Yak 1 home I was flying a wee bit faster in the patter than I normally would have.

 

So I tried to use slide slip to slow down on my approach, like I would do in IL2/46 or CloD.  To my surprise, it really didn't work well at all.  Very odd as normally the controls are all way too effective at all speeds.

 

I ended up flying away and let the AAA guns deal with the 109s, ( I was out of ammo )  and came back and did a less pressured, airliner like approach and got the thing down.

 

As as been said many times over, something is just not right here.

[6./ZG26_5tuka]

Allthough I think as well that the rudder induced roll is overmodelled, your video shows less than is possible with the BoS 109.

Sry, but I have to agree with Manfred. Pls make a video so we can see your speed, altitude, rate of descend and controll movements.

After testing this particularily on planes both in BoS and RoF I came to the conclusion it's a FM modeling issue in in both of the sims. As 777 pronouced their goal of simulating realistic prop wash effects on contorll surfaces.

 

Maybe that's the source of the issue that requires a little tweaking.

[BlackDevil]

You really shouldn't mention RoF in this context. The sideslips of the biplanes are just great. As I fly several biplane types, I can be rather sure about that. No sim is perfect of course, but there is no other one, which comes close to RoF.

 

This vid is from Quax: (he did have several landing vids in this forum as well, but they are deleted. I cant do vids - sorry)

 

https://m.youtube.com/watch?v=YN1wM-XXPUg

Edited January 11, 2015 by BlackDevil

[6./ZG26_5tuka]

You showed a slip turn, which is physically differently than a side slip. Try a straight approach form at least 400m away if you want to disprove me (not mean to be offensive, just tested some bi and tri planes and noticed this).

[BlackDevil]

I see a straight in approach after the turn. It's exactly the way you do the approach in RL. But I very seldom slip a biplane that hard. I just took that to show, that you can do this in RoF.

 

The guy did show the Udet landing with the RoF Fokker F7. It behaved exactly like in the famous Udet vid.

So please don't try to tell there is something wrong with sideslips in RoF.

Edited January 11, 2015 by BlackDevil

[andyw248]

This vid is from Quax: (he did have several landing vids in this forum as well, but they are deleted. I cant do vids - sorry)

 

https://m.youtube.com/watch?v=YN1wM-XXPUg

 

That's some pretty decent flying, he didn't even break the wings of the N17...

[StG2_Manfred]

Maybe you can do this in RoF. You can do it also in BoS to a certain degree, but the effect is too less (or completely absent?). I experience the same what BlitzPig wrote, so I would like to see a video where the plane is really slowed down due to the sideslip. I'm speaking only about BoS, subject is slipping the 109.

Edited January 11, 2015 by StG2_Manfred

[andyw248]

Maybe you can do this in RoF. You can do it also in BoS to a certain degree, but the effect is too less (or completely absent?). I experience the same what BlitzPig wrote, so I would like to see a video where the plane is really slowed down due to the sideslip.

 

A forward slip is used to make the approach steeper, but changing the airspeed is usually not a reason for doing a forward slip. So, if your approach speed is 200 kph you would strive to maintain that speed while slipping.

 

A side slip is used when there is a strong crosswind. You can use it to slip into that crosswind, thereby maintaining extended runway centerline. While side slipping you would normally try to maintain your established approach speed as well.

[StG2_Manfred]

Andy, that's not the point. You are bleeding energy while slipping, because of the higher drag, right? I can sideslip the plane and descent steeper or I can try to maintain my altitude and then getting slower, because I'm still losing energy due the higher drag. That's physics!

 

https://en.wikipedia.org/wiki/Slip_%28aerodynamics%29

Edited January 11, 2015 by StG2_Manfred

[Soarfeat]

Nice video and nice landing Andy.

--sf--

[-NW-ChiefRedCloud]

Thank you for this ....

 

Chief

[andyw248]

Did some dedicated testing of forward slips:

• Bf-109 F-4: I tried to slip with the stick fully deflected (as opposed to just flying a coordinated slip). This is harder because it requires a lot of opposite rudder, to prevent the aircraft from turning. However, when applying too much rudder the aircraft attempts to bank away from the slip. This makes slipping less stable than it is in RW (in RW the slip is very stable flight maneuver). A video is at: http://youtu.be/J3XP2ZmepWY.
• Yak-1: It is even harder to slip with full stick deflection. I resorted to flying a coordinated forward slip, which is quite possible. Video at: http://youtu.be/JxsWKspVuBc.
• Fw-190: I was unable to fly any sustained slip in the 190. It banked into the opposite direction no matter how careful I was with the rudder. This corresponds to the fact that it is also difficult to fly sustained stalls, "falling leaves", or slow turns in the 190. Don't want to bother you with a video of the crashes resulting from my attempts to slip the 190...

[6./ZG26_5tuka]

I see a straight in approach after the turn. It's exactly the way you do the approach in RL. But I very seldom slip a biplane that hard. I just took that to show, that you can do this in RoF.

Introducing the slip right after the turn or even within a turn is called a slip turn. It's again different.

A clean slip is to be started at final in horizontal approach. It's introduced by ailerouns and assisted by opposite rudder with a short delay - I guess you know that already.

 

No what's bugging both games equally is that their planes start to induct strangely strong roll momentums when using rudder - in BoS it's more obvious and hindering than in RoF.

 

A clean sideslip is rockstable depending on the wind and your angle, nothing "wonky" we see in andyws video (again great flying, andyw). Every airplane should be able to accomplish sideslips properly and while I haven't flown biplanes in reality this is not what I expirience in RoF with the majority of my owned airplanes (yes I dont own them all) as well as BoS.

[BlackDevil]

Introducing the slip right after the turn or even within a turn is called a slip turn. It's again different.

A clean slip is to be started at final in horizontal approach. It's introduced by ailerouns and assisted by opposite rudder with a short delay - I guess you know that already.

 

No what's bugging both games equally is that their planes start to induct strangely strong roll momentums when using rudder - in BoS it's more obvious and hindering than in RoF.

 

A clean sideslip is rockstable depending on the wind and your angle, nothing "wonky" we see in andyws video (again great flying, andyw). Every airplane should be able to accomplish sideslips properly and while I haven't flown biplanes in reality this is not what I expirience in RoF with the majority of my owned airplanes (yes I dont own them all) as well as BoS.

Could you please explain, what the aerodynamic difference is, wether you initiate the slip in a turn or after it ? I can't think of anything, I never heard of anything and I never experienced anything different.

 

I did acknowledge your second statement though, about the too strong roll momentum induced by the rudder.

Edited January 12, 2015 by BlackDevil

[andyw248]

Right, it seems that:

• The roll moment induced by rudder deflection is still slightly overmodeled. I think it was worse at some point during early access when snap rolls could be initiated with just the rudder, and has been improved since then. Basically, there should be some roll moment because rudder deflection starts a turn, thereby accelerating the outer wing, causing more lift from it, and decelerating the inner wing, decreasing its lift. But it seems there is still too much roll moment, or...
• ...the roll moment and the turn moment induced by rudder deflection are not properly harmonized. They could be better synchronized by:
  • Either reducing the roll moment induced by rudder deflection, and leave alone the turn moment induced by rudder deflection;
  • Or by increasing the turn moment, and keep the current amount of roll moment (although this might make the rudder too sensitive altogether).

While changing the synchronization or roll and turn moments induced by the rudder would improve the flight models of most aircraft, including the 109 and the Yak, it would probably not fix the tendency of the 190 to drop a wing. But that's a separate story.

[BlackDevil]

But there are plenty of anecdotes, that the 190 did rapidly drop one wing at stall. It snapped at accelerated stall without use of rudder and the wing drop was dangerous at landing as well ("normal 1 g stall").

[voncrapenhauser]

Well, thx for the video Andy.

 

Unfortunately, and as Stab/JG26_5tuka pointed  out, fwd and sideslip maneuvers in BoS are far from what we perform IRL. 

 

As a glider pilot I practice those almost in every flight :-), and our glider tugs to it as well, and indeed, the angles attained are way more pronounced than what you got in your video.

 

In fact, should you have tried to increase it and, just as 5tuka pointed out, you would run out of aileron to overcome the yaw induced roll :-/

 

I don't really know it it's due to overdone yaw-roll coupling, or to lack of aileron authority, or why, but it's not realistic the way it is right now ...

+1.

The sideslip manoeuvres in BOS actually work.......A little.

But agreed its still needs a tweak.

[voncrapenhauser]

I don't think there is a perfect sim, that's what the word means a Simulation.

But I must admit BOS has some better FM features than 1946 and feels closer to real flight than most.

If the Dev's can sort out the small problems with the FM I feel this would be nearer to perfect than most......if that makes sense?

Edited January 12, 2015 by voncrapenhauser

[Quax]

Hi BlackDevil,  where did you dig out this old N17 vid ?  Don't try to discuss FMs in this forum. I learned my lesson some time ago already 

 

Those know-it-all kind of guys even don't bother in doing some stick and rudder training, before they criticise the FM. 

 

 

 

...., but the modeling of sideslips is completely off in BoS (it only works somewhat with the Lagg-3 and Yak).

 

....atm BoS and RoF are the only sims I know  where it's impossible to accomplish a clean sideslip.

 

 

So I tried to use slide slip to slow down on my approach, like I would do in IL2/46 or CloD.  To my surprise, it really didn't work well at all.  

 

 

After testing this particularily on planes both in BoS and RoF I came to the conclusion it's a FM modeling issue in in both of the sims.

 

 

Maybe you can do this in RoF. You can do it also in BoS to a certain degree, but the effect is too less (or completely absent?......I'm speaking only about BoS, subject is slipping the 109.

 

 

A clean sideslip is rockstable depending on the wind and your angle, nothing "wonky" we see in ..... Every airplane should be able to accomplish sideslips properly .......

 

 

You don't talk about BoS, do you ?

 

Edited January 13, 2015 by Quax

[BlackDevil]

Thanks Quax

 

 

So I tried to use slide slip to slow down on my approach, like I would do in IL2/46 or CloD. 

Maybe this is part of the problem ? Better do it like in RL. Or do some additional training.

Edited January 13, 2015 by BlackDevil

[Sokol1]

Or maybe: set your stick, pedal sensitivity to minimum, do some video for TY. 

 

Reminder: Dont forget to re-set when go online. 

[6./ZG26_5tuka]

You don't talk about BoS, do you ?

 

Well congratulations, you managed to balme everyone and prove nothing....

 

Maybe you should try to listen to "know-it-all kind of guys" and real live pilots insteda of your virtually existing "expiriences".

 

The video you showed is a full flap dive with an slip like induced airbrake, not a side slip.

Also you also induced it in a turn making it a slip turn - second fail.

 

So in order to show all other, not particularily you, hwo a sideslip looks like in reality - by that i mean not like a 50° dive - I'll drop some more videos:

https://www.youtube.com/watch?v=CyzSHSaIlDc

https://www.youtube.com/watch?v=_kaxgbXiSNk

 

So in order to put things clear this is how to induct a sideslip:

 

1. Line up straight for final approahc with your desired flaps set and gear extendet

2. Hold your landing speed and attitude

3. When you have to reduce your altitude further bank your wing with roll into the dircetion of incoming wind and yaw into the oppositi dircetion. It's important you keep to roll first and aply rudder shortly after you started banking.

4. Use Power to maintain your rate of sink and change your approach angle for holding your landing speed. In reality your speed indicator would drop close to zero since the incoming air passes around the pitot tube insteda of inwards.

 

Pls show us another video where oyu accomplish this in a clean, realistic way as I can do in DCS.

 

For mods: I know he's just trolling but I hate it when people joing up in the forum starting a mess with totally inadequat attitudes and accusions proving nothing but their goal of trolling. We have many real glider and piston engined pilots contributing to this subject and most of them agree on this particular and BoS specific issue.

[BlackDevil]

Well congratulations, you managed to balme everyone and prove nothing....

Maybe you should try to listen to "know-it-all kind of guys" and real live pilots insteda of your virtually existing "expiriences".

 

That's more than funny

 

If you are from Germany, you perhaps watched Quax perform on an airshow already

 

 

PS: http://forum.il2sturmovik.com/topic/6242-interview-and-flight-109-fighter-ace/

Edited January 13, 2015 by BlackDevil

[Quax]

Hi jcomm, I fly without any curves. The slip is flown with full rudder and full aileron at balanced speed. Greetings

[andyw248]

Again, great flying! Maybe I was just too timid in my rudder application when I tried... makes me feel compelled to try again.

[6./ZG26_5tuka]

So, "5tuka"... I believe you were "offside" on your post ;-)

I admint I didnt expect him to be a real pilot by his attitude but it doesnt change what im saying. He showed us a high drag dive and declared it a clean sideslip which is wrong.

 

I've also participated in glider competitions where the jourey judges clean slips both into and with the wind. Do I get a coockie now?

 

Edit: Just to make it sure, I only got snippy because he put my name in his post arrogantly blaming everyone instead of using his expirience to contribute to this topic in a profficient way. I'm not wrong with being disproven by people with more knowledge / flight expirience, which I still feel I haven't been, but with posts such as his aiming.

Edited January 13, 2015 by Stab/JG26_5tuka

[BlackDevil]

 He showed us a high drag dive and declared it a clean sideslip which is wrong.

 

I see on the outside view full right rudder and left aileron. The plane is going straight. Can you please explain your point ? In the inside view the runway is steady in the sidewindow. That is how I fly a clean sideslip as well.

How do you do it ?

[6./ZG26_5tuka]

He is flying faster than landing speed, means with reduced rudder authority. Now the goal of that I (as well as many other were saying) was that the rudder induced roll momentum at landing speed is too high to enable clean and heavy slipping.

 

Sure, you can get around this issue by diving with full flaps, which probably caused damage in reality, or by slipping totally loosly to a slight degree. That's totally not my point. My point is, that what should in reality be max poissible with an airplane isn't possible in BoS due to stronger riudder than aileround roll momentum (at least on the 190 and slightly less on the 109).

 

I also try to work around it and with proper side wind sometimes have the slight emersion of a slip, but it's not what I see and expirience in real live regularily.

 

Edit: I hope to get my "The Other famous Sim"  running so I can hopefully record a video of slipping the Mustang and 190. This is just meant for comparison reasons, nothing hostile about it.

Edited January 13, 2015 by Stab/JG26_5tuka

[6./ZG26_5tuka]

Yesterday at gavagai's server I made it quite a few times in the 109 :-)

Well again I'm not sure I want to believe this wihtout a demonstration. I've seen slip turns and dives so far but no clean slips that convinced me it's true.

I'm using 0% sensetivity on all my equipment btw and the only thing I encounter while slipping is a unstable wobbling of the airplanes nose.

 

I'll work on a video which takes a fair ammount of time as I'm no proficient video editor. Hopefully this topic isn't locked by that time and we can discuss this constructuively.

[II/JG17_HerrMurf]

I have no videos to post but I’d like to throw my two cents in;

 

I’ve done a number of tests, prior to this argument, involving slips, maybe about two months ago. So, the FM’s have had a marginal tweak since then. Additionally, I fly the Fw almost exclusively, use rudder pedals and the other equipment can be seen in my sig.

 

1. I did slips with a strong crosswind while maintaining a good center line. I dialed up the test in the QMB to where I was looking out the forward corner triangle with near full deflection of the rudder and decent control with ailerons. I maintained my approach speed and kicked her straight in the flare prior to touchdown.
2. I did tests, and still set up my standard landings, with a break turn from 550-600 kph across midfield (200 meters) before stomping on the rudder, climbing slightly, and crossing up the ailerons. I maintain good control by reducing pressure on whichever control surface is required until my speed is in the 220 range and I am lined up with the center line.
3. I can bleed significant speed and maintain good control with full rudder and opposite aileron in any number of scenarios. Every time there is a FM tweak I do these test runs as well as chandelle’s, hammerhead stalls and snap rolls. Those last two are horrible in the Fw, BTW.
4. Lastly, and because I am in helicopters IRL, I did what I call an autorotation four or more months ago. I flew directly over my airfield at 5000m, applied full rudder and opposite aileron. I descended in that configuration at 240 kph while dropping like a stone in a small spiral around the field before lining up on the center line at 220 kph with a very short transition before the flare. I did make a TRAK file but it was lost in an update. If I can figure out how to convert it to a post-able video file I might do it again.
5. I never use slips as a combat maneuver as I have seen from Yaks and LaGGS - but curiously not from La-5's so far.

I don’t use any curves and can perform any number of slips and out of trim maneuvers with adequate control. I metered the throttle in all of these maneuvers as appropriate for the target airspeed – chopping it on the break turns and “autorotation.”

Edited January 13, 2015 by HerrMurf

[6./ZG26_5tuka]

Again above landing speed, but well...guess i have to live with it if everbyody's argumenting about  it being fuine because they can work around it

Just one thing though, Slipping is used to reduce additional altitude during your final approach, not your airspeed. When inducing a clean slip in reality your speed will not change but your sink rate.

The reason why slips may be possible at higher airspeeds is due to less rudder // more aileroun authority you get in this range. The proportion is way off at approaching speed though, which is 180 km/h for the 109 and 190-200 for the Fw190.

 

I'll give it up. You won, the "know it all guys" and real pilots all agree with you. Well done, I'm out of this discussion. Just one minor thing to note though, my "slipping technique" can not be far off since it's working perfectly fine in the other sim, not in BoS where 50% rudder input throws my whole plane over like a wet piece of paper.

Edited January 13, 2015 by Stab/JG26_5tuka

[II/JG17_HerrMurf]

I wasn't picking a fight, just giving my experience in the game. I realize my approaches are generally 10% or so above standard but I'm OK with that. I will try the above tests at the slower speeds and get back to you.

 

I don't know if the aircraft FM's are 100% accurate - I suspect they are not - or if the slip is modeled exactly as it should be. I just don't think it, and particularly the physics model in general, are as broken as some have stated. FTR, in real life I only used slips if I was both too high AND too fast. I haven't flown a fixed wing in a while though. Crabbing into the wind was a different story.

[indiaciki]

Why doesn't anybody send an email to let's say kermie or some other warbird pilot just asking??? It's the same ballgame. I was talking to my dad about flying the soko 522 a yougoslav 600hp trainer he flew a couple of times. He did his basic in an utva aero 3 trainer with a lycoming. Told me that besides weight and full metal construction the execive power of the radial engine made quite a diffence. Maybe the tendency to roll has more to do with things like that. My guess. You can't compare flight in a overpowered heavy fighter with slipping a glider or light GA aircraft. Military aircraft even heavy trainers are less stable in any maneuver than a cessna or glider. And the gyroscopic effects are way greater = less lateral stability. It doesn't mean that the BOS model is right. Just thinking.

[StG2_Manfred]

My statements were based on experiences with 190. I admit the subject is slipping the 109, nevertheless it would be much more interesting to see the 190 in an slipping landing approach, because it's much harder imo. And also the sovjet planes, they probably / maybe  have the same difficulties.

Edited January 14, 2015 by StG2_Manfred

[andyw248]

Like I said I couldn't resist and tried to reproduce Quax' technique (albeit in the Yak-1). The result can be seen here: 

 

http://youtu.be/WO_Bn4uY_I8

 

Now I have to say that I was still unable to pull off that technique; applying full rudder led to not having enough aileron authority and the plane banking off into the direction of the rudder.

 

However, with a little practice a nice slip can be done by:

• Reducing power to idle
• (Optional) I did not use flaps, but it can be done with flaps down as well
• Letting the nose dive down a little so that the plane can pick up a little speed; in the case of the Yak-1 the normal approach speed on final with the flaps up would be 170 * 1.3 = 221 kph. The slip is more stable when flying it at 250 kph.

Still more tricky than in an average GA plane, but doable. And yes, I would still like to find out how to fly a slip with full rudder. Like the other slipping folks here I don't use curves.

[Dakpilot]

Just a small point, is it documented anywhere that full rudder was used to sideslip these type of aircraft, they are much heavier/more powerful than G/A, sideslip is used to lose height without increasing speed on a high landing approach, perhaps we are trying to do manoeuvres that are more common in light G/A aircraft with a much larger critical flight envelope, I know in some of the larger A/C I have flown a 'full' sideslip would not be recommended at or below Vmca and is only used when having made a sloppy approach anyway    ( in normal wind conditions) 

 

 Also has anyone noted the effects of slats in these experiments

 

Cheers Dakpilot