Controllability on the ground

[TimC]

Hello All,

I realise that this topic has been covered in various guises before, however I would be grateful for any advice that you may have. I recently purchased the TBM 900 but have yet to carry out a controlled take off and significantly a landing and roll out without leaving the runway. I use the Thrustmaster Warthog throttle and stick, and have set the throttle friction control for rudder inputs. I have tried various settings using the x plane 11 sensitivity panel but to no avail.  I realise why many people adore this model and it certainly is beautifully modelled, with detailed systems etc but it is very frustrating to have key elements of a flight to be so problematic. Thank you in advance. 

TimC. 

[DwightP980]

4 minutes ago, TimC said:

Hello All,

I realise that this topic has been covered in various guises before, however I would be grateful for any advice that you may have. I recently purchased the TBM 900 but have yet to carry out a controlled take off and significantly a landing and roll out without leaving the runway. I use the Thrustmaster Warthog throttle and stick, and have set the throttle friction control for rudder inputs. I have tried various settings using the x plane 11 sensitivity panel but to no avail.  I realise why many people adore this model and it certainly is beautifully modelled, with detailed systems etc but it is very frustrating to have key elements of a flight to be so problematic. Thank you in advance. 

TimC. 

@TimC Try the following:

1. Power the TBM-900 up.

2. Turn the Auto-Pilot On (switch located the overhead panel righthand side)

3. As soon as the PFD's and MFD have powered up go to the TRIM section of the MFD (lower left corner)  and move the RUD trim to the center (white tick mark) and the ELEV to the T/O white tick mark.

4. Toggle the Beta Prop switch located under the Power lever on the left side to enter Reverse and the Taxi power range.

5. When you have aligned with the runway for Take Off bring the power up to 40% prop torque indicated (or very close) stabilize power and on the takeoff roll easy power to takeoff power.

By playing with the above settings my TBM is very much so controllable for Take Offs and Taxi. My preference for the Control Sensitivity for my controls are set to 50% for both Control Response and Stability Augmentation.

The RUD trim (#3 Step) is likely the biggest culprit as I was lining the tick mark up with the BLUE mark. Mine handles best when trimmed to just touching the right side of the WHITE mark.

Your mileage may very as they say ;-)

Regards!

Dwight

 

[RobW05]

Just like DwightP980 said, I had a hard time too until i figured out not to follow the book and set rudder trim way right. 

A slight right rudder trim works best for me. 

Although it is of course depending on your hardware, I always set sensitivity and stability augmentation to zero and I have set a rudder response curve a little flatter than default in the first quarter. That gives me the fine control needed to stay on the center line easily. 

For landing I think speed is the key, if you're coming in too fast you will more likely have a hard time to stay on the centerline. Also don't forget to center your trims before landing, and never just slam in full reverse. Just take back power into beta mode right after touchdown. When you get your speeds right on final you will notice you need little to no reverse at all to get down to taxi speeds. 

Edited February 20, 2019 by RobW05

[TimC]

Thank you both very much for your quick responses. I have taken snippets from both of you and completed a couple of circuits at KMCO without deviating onto the grass! Definitely helped not trimming the rudder to the right t/o marker and indeed for me just a smidgen to the right of centre works best. I have just tested with Sensitivity and Stab. augmentation at 50% and will try 0% on both later. I also flattened the rudder response curve but would be interested to see a graphic of your (RobW05) rudder response curve. For your info Dwight, I spent many happy hours in RW, flying out of Vero Beach (Flight Safety Int.) not far from you.

[RobW05]

You´re welcome!

Here´s the rudder response curve I use for the TBM900.

[TimC]

Hi Rob, thank you. I'll give it a whirl.

[JYW]

The biggest thing that improved all aspects of ground handling (taxi and t/o roll) in the TBM for me, was setting "stability augmentation" on the yaw axis, completely off.     I'd turned it on, assuming it would settle things down, but now understand the TBM was coded specifically for this value to be off. With it off, and by following these tips, I no longer have any issues; ground control is now perfect (and believe me, when I first tried the plane, it was absolutely awful!)

- Rudder trim MUST be set, but not as far as the green area; about half way between neutral and the green area.

- Calibrate your rudder pedals axis in your controller profile, before EVERY flight.

- Introduce power very steadily on the take off roll (I usually take off with 85-90% torque).

.....another optional tip that can settle the TBM's control sensitivity down, is to carry extra fuel.

Edited February 24, 2019 by JYW

[TimC]

Hi JYW, thank you for your input. Handling is a lot better following the changes I made since taking the advice from Rob and Dwight. I will try the stability augmentation on the yaw axis to off for the next flight.

Kind Regards,

Tim.

[DwightP980]

On ‎2‎/‎20‎/‎2019 at 1:21 PM, TimC said:

Thank you both very much for your quick responses. I have taken snippets from both of you and completed a couple of circuits at KMCO without deviating onto the grass! Definitely helped not trimming the rudder to the right t/o marker and indeed for me just a smidgen to the right of centre works best. I have just tested with Sensitivity and Stab. augmentation at 50% and will try 0% on both later. I also flattened the rudder response curve but would be interested to see a graphic of your (RobW05) rudder response curve. For your info Dwight, I spent many happy hours in RW, flying out of Vero Beach (Flight Safety Int.) not far from you.

@TimC Hello Tim, Glad to hear the tips are working, and with the more time you put into this aircraft, the payoff will be immense.

By the way, I see you are flying circuits at KMCO. This is home base for my TBM (I always park around the Signature ramp area) and I normally fly from KMCO to KLAL, KTPA, KSRQ, KRSW, KMIA. After downloading some custom scenery, and airports, spending some time watching YouTube on how to setup the custom scenery files X-Plane, it is awesome. Blue skies to you!

Regards,

Dwight

[TimC]

Hello Dwight, yes I'm really enjoying this model. I have the KMCO installed and will look at the others you have mentioned. I used the Signature ramp area when I collected my FAA licence.

Regards,

Tim.

[Sims Smith]

On 2/20/2019 at 10:01 AM, DwightP980 said:

4. Toggle the Beta Prop switch located under the Power lever on the left side to enter Reverse and the Taxi power range.

I am not following #4.  Is that an extra procedure? Don't we have to do that anyway to taxi the aircraft at lower speed?

[ChuckO]

Good news on this topic: the V1.1.9 changes to ground model have eliminated directional skittishness on takeoff and landing !

[Jacoba]

4 hours ago, ChuckO said:

Good news on this topic: the V1.1.9 changes to ground model have eliminated directional skittishness on takeoff and landing !

But not during taxi...

[Goran_M]

5 minutes ago, Jacoba said:

But not during taxi...

Can you post a video of what you are experiencing.  I was watching a stream last night, and everything was fine, including taxi.  

[WaarEagle]

I've never had any problems taxiing the TBM.  Even before the latest version, it only became really skittish at higher speeds... now it handles well at all speeds.

[RobW05]

6 hours ago, Jacoba said:

But not during taxi...

You mentioned in another thread that you don't use rudder pedals. I think that's contributing mostly to your problems. 

I would recommend using pedals or at least the twist axis of a flight stick. 

[Jacoba]

22 hours ago, Goran_M said:

Can you post a video of what you are experiencing.  I was watching a stream last night, and everything was fine, including taxi.  

No video but a simple description. First I don't own rudder pedals on my sim set up. 

Most all other planes auto coordinate rudder and ailerons. Turning on the ground is accomplished as if I was banking or turning in the air.

But with the TBM I experience very little turning, so my turning radius is huge, easily 10 times what is should normally be.  

Edited April 29, 2019 by Jacoba

[sqrt(-1)]

34 minutes ago, Jacoba said:

Most all other planes auto coordinate rudder and ailerons. Turning on the ground is accomplished as if I was banking or turning in the air.

The TBM is a study-level model.  As on the real aircraft, steering on the ground is not done by merely turning the yoke like a steering wheel.

[Goran_M]

Yeah, I'm afraid you'll need to, at least, use a couple of keys on the keyboard for steering.  AFAIK, the reason the TBM doesn't auto co-ordinate is because the ground steering is code driven.

[Jacoba]

2 hours ago, sqrt(-1) said:

The TBM is a study-level model.  As on the real aircraft, steering on the ground is not done by merely turning the yoke like a steering wheel.

Yes... I fly a real one, so yeah...

[Jacoba]

1 hour ago, Goran_M said:

Yeah, I'm afraid you'll need to, at least, use a couple of keys on the keyboard for steering.  AFAIK, the reason the TBM doesn't auto co-ordinate is because the ground steering is code driven.

Well, that solves my riddle, guess I'll just have to invest in a good set of pedals. 

[sqrt(-1)]

44 minutes ago, Jacoba said:

Well, that solves my riddle, guess I'll just have to invest in a good set of pedals. 

This was precisely the point I was trying to make.  Since you fly a real one, you'll enjoy this model so much more with a proper set of pedals.

Cheers!