Strange problem with this plane

[jfri]

I have tried out all the training sessions by now. When I started with the missions I discover something weird. I'm unable to take off since the plane just at or after takeoff is impossible to control. I will roll mostly to the left until I crash. I find for example that I need full left rudder and aileron to counteract this for short while (but soon after that the plane crash being so difficult to control). I'm positive about applying 5 deg right rudder trim. Strange thing is that when I directly after this happening goes back to the training take off session I rarely experience any problem in the take off run. I understand nothing. I use CH Flight Yoke and rudders.

I attach a trk file over a session where I encountered this problem.

p51.trk

[Suchacz]

IMHO your crash was causeb by 2 factors

 

1 - you pulled her too hard after the lift off, which caused stall

2 - the crosswind from the left. When your left wing went down, the crosswind blew it down even more

[Konrad Friedrich]

The first thing: You trimmed the plane tail heavy.

The yellow marking on the trim wheel of the elevators only looks like it's trimmed nose heavy. This is apparently a problem of the view point of your 'virtual eyes'.

When you check the position with TrackIR and take a look from the side you can see it's trimmed neutral.

Leave it where it is when you begin your start up procedure.

 

Next fault was to try to hold the tail wheel down for that bit too long.

Let tail wheel rise when it wants to rise and run on the front wheels for a while.

The moment the plane took off, the slightly tail heavy trim and your somewhat startled overcompensation (:joystick:)of the immediate lift, the sudden too high angle of attack, the torque of the engine twisted the plane, you pulled even more to get it off the ground, you pulled to the right to counter the dropping left wing, even more 'aoa', even less lift, left wing stall - and that was the end... :cry:

 

Btw:

- Prime a little bit longer. 3-4 seconds is ok.

- Uncage your flight indicator.

- You shouldn't taxi with 1500 rpm- especially not with an cold engine... 1000 rpm is enough.

Edited May 30, 2013 by Konrad Friedrich

[strikeeagle]

If you roll left and the propeller turns to the right, it's called torque. Also you may want to change your take off technique. Let the tail lift off of the ground first, gently apply back pressure, and let the airplane "fly off" the ground.

[jfri]

IMHO your crash was causeb by 2 factors

 

1 - you pulled her too hard after the lift off, which caused stall

2 - the crosswind from the left. When your left wing went down, the crosswind blew it down even more

 

I tried the suggestions given here and this time it went good. But I still think it strange that I didn't always encounter the same problem when I tried the training session. Does the missions have crosswind but not the training sessions ?

[Napa]

I tried the suggestions given here and this time it went good. But I still think it strange that I didn't always encounter the same problem when I tried the training session. Does the missions have crosswind but not the training sessions ?

 

Fly with no wind and practice your takeoffs.

 

Let the engine to warm up nicely but be aware of your gauges not to burn it, don't trim the elevator, only trim the rudder about 5 degrees to the right.

 

On takeoff - When you increase the throttle do it gently (very gently). The aircraft can lift off very easy (it's a fairly light aircraft with a very powerful engine) and the runway is long so you have plenty of runway to compensate and control the takeoff.

 

As others said, let the tail to rise by it's own and then after a few seconds gently again raise the nose just a bit, the plane will fly off the ground easily.

 

The trick is to increase throttle very gently at takeoff.

[mmaruda]

Ok here is my controversial point of view: the ground handling in the Mustang is still broken. :)

 

Anyway what you cannot do i s apply to much throttle at the start. I am not sure about it, but I heard that it is possible to firewall the throttle on take-off in the real plane. In DCS that is a big NO NO. You need to roll slowly to be able to use rudder to control the roll.

 

The main problem here is once you loose control and start spinning out, there is no countering it.

 

My advice? DITCH THE RUDDER TRIM. I found that the whole 4-5 degrees is just what causes problems on take-off. At a slow speed you will actually be pulled to the right, so you counter that and start going left, you counter that too and there comes a weird pendulum effect and eventually you loose control. Without rudder trim all you need to do is use right rudder only, you will have to work more with the foot, but it is actually possible to take off in a straight line instead of being all over the runway. Another curiosity is that this is actually a lot easier with a twisty-stick than pedals.

[Suchacz]

Does the missions have crosswind but not the training sessions ?

It seems, that the crosswind is pretty strong, you can see it on the smoke above those chimneys. That is quite tricky for take off and landing.

 

...and yes, you should be as gentle as you can and treat her like a baby. Even when you're not enough familiar to each other. She's not some lazy Cessna for civilian tourists, she's real military grade thoroughbred :D

 

Edit: I took control of your track and I found that crosswind really tricky. Those aren't the best conditions on your first date with her :joystick:

You should familiarise with her on some sunny and calm day :smilewink:

Edited May 30, 2013 by Suchacz

[Wolf Rider]

Ok here is my controversial point of view: the ground handling in the Mustang is still broken. :)

 

Anyway what you cannot do i s apply to much throttle at the start. I am not sure about it, but I heard that it is possible to firewall the throttle on take-off in the real plane.

 

torque usually creayes a dire effect if that is done... a heck of a lot of horsepower being released at once could result in the plane ending up on its side, being sent in left-hand circles or just simply being thrown left - depending on plane

 

 

In DCS that is a big NO NO. You need to roll slowly to be able to use rudder to control the roll.

 

Rudder has no authority (effect) until a certain airspeed is met

 

 

 

The main problem here is once you loose control and start spinning out, there is no countering it.

 

 

on the ground, the rudder pedals control the tail wheel - keep back pressure on the stick to keep control of the tail wheel until rudder authority is (almost?) achieved... helps prevent loss of control and spinning out

 

 

 

My advice? DITCH THE RUDDER TRIM. I found that the whole 4-5 degrees is just what causes problems on take-off.

 

 

 

Rudder trim is necessary when authority is achieved to help counter the effect of torque... why? because the tail wheel is now off the ground ( it can be done without trim, but the pilot may find himself needing to be way right foot heavy and having difficulties in compensating)

 

At a slow speed you will actually be pulled to the right, so you counter that and start going left, you counter that too and there comes a weird pendulum effect and eventually you loose control. Without rudder trim all you need to do is use right rudder only, you will have to work more with the foot, but it is actually possible to take off in a straight line instead of being all over the runway. Another curiosity is that this is actually a lot easier with a twisty-stick than pedals.

 

yes, the flyer has to paddle the rudder a bit. its doable, necessary and gets you airborne.... sorta got to learn to pre-empt a little bit what is going to happen

Edited May 31, 2013 by Wolf Rider

[mmaruda]

Wolf Rider, the way you put it seems simple, but it takes me several attempts to get airborne after a flying break and the best way is to forget all the tutorials and do it my way:

-no trimming of rudder

-keep the tail-wheel locked as long as possible

-MP around 20 until I reach 90 MPH, than increase and lift of ASAP, before I crash

 

Another thing are the landings - I made an hour-long flight today over the mountains but when I finally came in to land attempting a 3-point touchdown around 90 MPH, the plane went sideways immediately. I drifted like 100 meters and came to a stop. Nothing broke. I have no idea why I went sideways, probably should have landed normally instead of that 3-point attempt, but how on earth did the wheels hold up?

 

In the Su-25, when you land and try turning at that sort of speed, you immediately blow the front tire. The ones in the Mustang seem to be made of titanium.

 

If this ground handling is realistic, how on earth did they train WWII pilots without crashing thousands of planes?

 

Maybe I'm just doing it wrong, but doing stuff according to tutorials and other people's advice usually gets me crashed.

[fantomk]

If this ground handling is realistic, how on earth did they train WWII pilots without crashing thousands of planes?

 

I think exactly the same. I have been playing other flight simulator games for years but I found that DCS P-51 is extremely difficult to take-off. I forgot how many times I ended up in a fireball beside the runway shortly after I released the parking break and pushed the throttle (I swear I pushed it very gently), so I wonder during WWII how many newbie pilots and instructors lost their life on their first day training on the P-51.

[ophiuchus]

I'd suggest more practice ;) And learn to feel and predict the aircraft behavior, especially during takeoff. Here's how I do it with an old Saitek's Cyborg Evo, without ffb, and no rudder pedals. Well, the throttle quadrant is very helpful, but as you will see, it's not that crucial. Turn on the controls indicator while in cockpit view (RCTRL+Enter) so you can see stick and rudder movements during most demanding parts of flight. (Clear weather, and stuff, but for training at the beginning, that would be useful).

quick_P-51D.trk

[mmaruda]

No pedals is actually easier - I only started having problems when I switched from X-52 to CH.

 

When I used the twisty stick, I had no idea what all those people were talking about in first take-off thread after release. :)

[Merlin-27]

I think exactly the same. I have been playing other flight simulator games for years but I found that DCS P-51 is extremely difficult to take-off. I forgot how many times I ended up in a fireball beside the runway shortly after I released the parking break and pushed the throttle (I swear I pushed it very gently), so I wonder during WWII how many newbie pilots and instructors lost their life on their first day training on the P-51.

 

I think those results are a product of a few disadvantages to the virtual pilot... Firstly most new pilots didn't go near a P-51 until after many hours of flight training on less formidable aircraft. (once a pilot got to a P-51 he was on his own. No instructor along for the ride) The ones who couldn't master the training aircraft did not proceed. Secondly, no matter what time you've spent in "other" sims, DCS is on a different level and there are many new things for us all to learn. And lastly, when it's your actual life on the line you tend to make less stupid mistakes :)

 

I'd say, after becoming very comfortable with the DCS P-51 that a good amount of practice and adjusting your controls to a comfortable config along the way will get you to a point where you will only crash on take-off if you try to rush things or get incredibly careless.

[Pman]

Its perfectly do able to take the stang off with no rudder trim for the take off, its just abit more work as the tail lifts and upon the initial climb out.

 

If you are flying a light and clean aircraft I would try taking off with much lower settings and you will be surprised how smooth if can go up. Even down at say 2400rpm and 35" of pressure.

 

If you want a rough take off try 100% fuel with tanks and some rockets to boot ;)

 

but on a more serious not dont try and force the aircraft into the air, it will head skywards easily if you can control the throttle correctly.

 

Pman

[SharpeXB]

If this ground handling is realistic, how on earth did they train WWII pilots without crashing thousands of planes?

They did crash thousands of planes, there were something like 50,000 accidents and 19,000 pilots killed in the continental US during WWII.

I'm reading a great book "Fighter Pilot" about Robin Olds. He is given a P-51 to fly in WWII with little or no instruction and crashes it the first time he tries to land it. He's used to a P-38 twin engine and the prop torque surprises him when he hits the throttle at low speed.

[mmaruda]

Ok, so I got the proper take-off down. Turns out if you follow the exact instructions of the tutorial (MP at 30 before letting off the brakes), there is less side drift. I never went that way, since it did not work in the early beta and I never replayed the tutorials later. Still, I think that the sideways show need to be fixed somehow, at least the gear or tires should brake before you can go all drift king.

[Pman]

Ok, so I got the proper take-off down. Turns out if you follow the exact instructions of the tutorial (MP at 30 before letting off the brakes), there is less side drift. I never went that way, since it did not work in the early beta and I never replayed the tutorials later. Still, I think that the sideways show need to be fixed somehow, at least the gear or tires should brake before you can go all drift king.

 

why?

 

Thats how the real aircraft is....

[SharpeXB]

I found the real key statement in the manual regarding takeoff is this:

p 130 "It is recommended that 61 in.Hg and 3000 RPM be used for takeoffs and that this power setting is reached as quickly as possible after the takeoff run is started. However, advance the throttle smoothly and never jam it forward."

If this wasn't working for me I found it was because I wasn't following the wording exactly. Do exactly what this says and the plane flies easily right off the ground.

[mmaruda]

Well, the early version of the sim had it all wrong - even the AI crashed on the take-off demonstration mission.

[Pman]

Well, the early version of the sim had it all wrong - even the AI crashed on the take-off demonstration mission.

 

That was because the track that was played in the demo was recorded in a prior version, they changed the FM and so the track was no longer accurate.

 

Had nothing to do with it being "wrong"

[Wolf Rider]

Ok, so I got the proper take-off down. Turns out if you follow the exact instructions of the tutorial (MP at 30 before letting off the brakes), there is less side drift. I never went that way, since it did not work in the early beta and I never replayed the tutorials later. Still, I think that the sideways show need to be fixed somehow, at least the gear or tires should brake before you can go all drift king.

 

Well done :thumbup:

 

Ground looping is part of the side effect of torque

[Weta43]

Robin Olds - triple ace ( WWII / 'Nam )

 

The 479th FG converted to the P-51 Mustang in mid-September. On his second transition flight, at the point of touchdown during landing, Olds learned a lesson in "false confidence" when the powerful torque of the single-engined fighter forced him to ground loop after the Mustang veered off the runway

[PeterP]

:D...to make it understandable/visual for the "average joe" what happens when the torque gets stronger than the plane can take at a current speed/airflow over the wings :

Edited June 1, 2013 by PeterP

[leafer]

HAHAHAHAHAHA. I did not foresee that. Nope. lol