Spit IX Rollout Issue

[Toots_LeGuerre]

The Spit IX feels wonderful to  fly.

It is easy to land.

But at the end of the rollout, at very low speed, just before it should come to a stop, it ground loops.

Differential braking seems to have no effect,. though wheels are still rolling, though slowly..

Rudder ineffective as one would suspect at these  low speeds.

I tried a WW1 blast of engine power across the rudder, which only aggravated it.

Every Spit pilot I have spoken with says the plane rolls out straight with no tendency to GL.

 

Makes me think of the early days of the LaGG 3 which has the same free swiveling tailwheel.

A patch that cured the problem ended its days pirouetting like a ballerina.

Anyone else have this problem?

If so, maybe a patch is in order.

Can't say about the Mk V as I don't have it.

 

Any suggestions, techniques, etc?

Thanks

[ZachariasX]

On 4/28/2019 at 3:05 PM, vonNutz said:

Anyone else have this problem?

It is a very much debated topic here and the importance of "realistic" ground handling is subject to personal opinion.

 

What I can tell you is what you describe as a "problem" is actually a solution to others. Brakes bite slow in this sim. You can click toggle full brakes and as soon as you cllick 100% brakes, you will see that the brake lever is actuated slowly instead of applying 100% brake force right away. (Like it does in Prepar3D for instance, resulting in an immediate noseover in case of planes like a Spitfire. At least, that's how some implement it.) Here, you can taxi the Spitfire by using the pinky switch "lever", just clicking as much as you need to get differential brake. I assume (might be wrong, but devs surely know the numbers) that most people use simpler input devices with no axis that can be mapped for breake lever/pedals. The combination of slower actuated braking as well as reduced bite to accomodate the "click" makes it possible to taxi simulating a true lever axis. In principle, all fine there.

 

The problem you are describing comes from another thing: To prevent a ground loop, you must use swift and strong inputs. In the current situation however this is much less possible, asking from you to act even sooner for a smaller, delayed correction to do the job. It is further intensified by the planes behavior to be more like on ice. The tail really likes to come around, whereas real tail draggers that I am familiar with handle very straight forward with no such tendencies provided that you keep the tailwheel locked and you do not try to pivot turn.

 

Also in BoX, planes with a narrow undercarridge do not readily tilt to the side, it really takes a lot to do so. In real taildraggers, I'd be careful about such. It (together with very effective controls at low speed) masks the speed with which you're actually taxiing. People here are often really racing on the taxi ways. If you noticed the plane tilting to the side when driving circles, you'd be less surprised for the tail coming around. In the game it almost only tilts when the tail actually comes around.

 

There was a patch that mended some of the most pressing issues of how the sim handles ground ops (especially the Mig-3) but the main artifact really becomes visible in the roll after a landing, where you have no effective rudder for quick reactions. As the tail wheel really does little in keeping you straight (even on grass), all you can do is keep her absolutely straight when touching down and do never try to make a turn unless you're about to make a full stop.

 

Bottom line of this is that takeoffs are way too easy but landings (and taxiing if you're in a hurry) are way too hard. But if you adjust to it it is manageable. How bad that is, you decide. Also, I do not know much much corrections in that department are just related to individual aircraft modules or if it is a general property of how the sim engine handles things. Only devs will know if corrections there are really a low hanging fruit.

[Toots_LeGuerre]

Thanks chaps.

Some very good points.

I reset the Z axis (Rudder) to 50%, which makes the twist stick inputs

I am reluctantly using currently a bit less chaotic.

 

Aggressive braking and rudder use will catch most of it now.

At the rollout end, almost stopped, it still wants tol GL.

 

I'm an RL pilot and have flown numerous taildraggers.

Super Cubs, some vintage others, etc

None acted like this.

 

Thanks for the replies.

 

[ZachariasX]

1 hour ago, Rekt said:

Maybe just make the brakes a little more effective or something?

On the contrary, brake less. Braking makes the tail come around. You would need the brake lever to be actuated faster, not having stronger brakes. Land straight and let it roll, be easy on the brakes. Keep the stick pulled fully back. If it become "complicated", add ~30% throttle and rudder will help you. This works for all aircraft, the Spit just being one where this is very prominent. The narrow landing gear induces little momentum compared to wide tracks. It gives enough twist momentum to start the disaster but not for mending it. The 109 has a relatively effective locked tail wheel, keeping it more straight than the one in the Spit.

[Toots_LeGuerre]

The big problem with aggressive braking on a Spit is it's a nose over waiting to happen.

If I recall right, the Center of the LG main wheel axle, when the plane is leveled, is something like 7 inches ahead of the Center of Gravity.

On a Mustang, it's over 4 feet.

Don't quote these figures, just something I seem to recall reading somewhere.

 

The way to land a Spit, I am told, is land directly into the wind if possible, (it hates crosswinds),

on grass, and let the drag of the grass slow the plane.

Can't always do that these days.

 

Thank you for the replies--all very interesting

[69th_Mobile_BBQ]

Take it into single player QMB. 

Start on an aerodrome (big open field) type runway. 

Taxi the aircraft. 

Find the lowest possible throttle setting that will keep the plane rolling forward. 

 

Apply that throttle setting to the plane the moment it touches down.

With some minor adjustment, you should be able to avoid ground looping as the plane rolls back to the slowest possible taxi speed.  

Carefully apply brakes and rudder as needed. 

Edited May 3, 2019 by =AVG77=Mobile_BBQ

[jaygee485]

On 4/29/2019 at 1:05 AM, vonNutz said:

But at the end of the rollout, at very low speed, just before it should come to a stop, it ground loops.

Differential braking seems to have no effect,. though wheels are still rolling, though slowly.

 

My experience exactly.

I'm very much a novice, and only recently unchecked 'Simplified flight physics' in Custom mode settings.

Since I did that, I now consider it to be a good landing in the Mk IX if the wingtip doesn't contact the ground

in the inevitable groundloop just before it comes to a stop.

Even though I'm anticipating it, and apply full opposite rudder and brake the moment it begins, I still can't prevent it.

I've tried adding some throttle after touchdown, but that hasn't helped.

I know that others have mastered this quirk, and I'm sure it just requires super-anticipation and super-skillful

pedal dancing, so I'll keep practicing! 

[56RAF_Roblex]

I have got used to the Spits quirks and I am usually OK as long as I pay attention on landing but I will admit I have never seen any documentation to say it should be so hard to keep straight on the rollout.  To the contrary,  when the US comprehensively tested the spits handling they specifically commented "The airplane exhibited no dangerous ground-looping tendencies in landing"    The last comment is interesting too.  Some people have questioned how the Spit seems almost unstallable if you lift the nose at low speeds but it would appear that is authentic.

 

 

http://www.wwiiaircraftperformance.org/NACA-Spitfire-V-Stalling.pdf

 

I also remember a spitfire display pilot being asked by a member of the flight sim community if the spit was hard to handle on the roll out and the pilot being a little bemused that anyone would think so.   Sorry I cannot find the reference for that.

Edited May 4, 2019 by 56RAF_Roblex

[Toots_LeGuerre]

Reginald Mitchell designed a very difficult wing to build--all curves and a big D Box leading edge.

He also saved a lot of young pilots lives.

The Spit has a 2.5 degree downward twist that means the wing root stall first, leaving the ailerons till last.

So control is maintained.

The 'judder' the pilot feels in the stick and airframe, tells him he's at the stalling point, so ease off the stick pressure.

This was modeled quite well into the old "Battle of Britain II, Wings of Victory, as I recall from years ago.

It worked beautifully, so it certainly could be modelled into the current Spit's flight physics.

 

Unlike many of these historic aircraft, there are a lot of Spitfires still flying, many are converted to two-seaters.

What The devs need to do, is book a flight, setting up some monitoring instruments.

There is a Spitfire Flight Simulator with a full-sized cockpit at Boultbee Flight Academy at Goodwood in Chichester.

It cost a lot of time and money, I hear.

But Wow . . .