Cannot get the plane trimmed for landing.

[Wildwind]

So, I'm trying to work on my Case 1 recovery, and everyone says that trim is the key to doing it right, and that probably explains why I can't do it with any consistency at all, because I cannot get the plane trimmed anywhere close to level flight.

 

I put the wings in sweep as described, and then I click the trim hat in the nose-up direction as many as 60 times and it still tries to nose dive into the ocean.

 

I can't tell that the trimmer is making any difference at all.

 

I can trim the aircraft at other times. I can trim it while doing air-to-air refueling and get it exactly where I want it.

 

But for some reason, it seems like when I am trying to set up for landing, the trim hat seems to do nothing at all no matter how much I push it! I try clicking it, I try holding it down, I've tried everything. It seems like no amount of trim is sufficient.

 

Similarly, after I have the wings open again, no amount of trim seems sufficient to hold the thing at 15 units of AoA. The nose continually wants to drop.

 

This isn't a matter of not being able to get it precisely right. I'm not getting anywhere close to right. It's a matter of the trim hat just seeming to not DO anything while I'm trying to land the plane.

 

I'm exasperated and confused, and I have no idea why something that seems to work correctly at all other times seems completely useless when I am trying to trim for landing.

[Raven (Elysian Angel)]

and then I click the trim hat in the nose-up direction as many as 60 times and it still tries to nose dive into the ocean.

 

Silly question perhaps, but have you tried holding down your trim key/hat for a bit instead of using single clicks? I usually look at the pitch trim indicator, and move it straight away to 10 degrees for landing, and make small adjustments thereafter when necessary.

I have no problem at all with trimming on landing.

[Wildwind]

 

Silly question perhaps, but have you tried holding down your trim key/hat for a bit instead of using single clicks? I usually look at the pitch trim indicator, and move it straight away to 10 degrees for landing, and make small adjustments thereafter when necessary.

I have no problem at all with trimming on landing.

 

Yeah, I've tried that, too.

 

I'm starting to wonder if something is wrong with my joystick configuration, but it was working last night when I was practicing AAR.

 

After further experimentation, it seems that nose-up trim just doesn't work for me for some reason. Nose-down trim works. Roll trim works. Rudder trim works. Nose-up trim does nothing at all.

 

This explains a lot, but I am somewhat baffled as to the reason for it. if I am in the control bindings menu and push the hat in that direction, it registers, so I know the hat on the joystick is not dead.

 

EDIT: I think I may have fixed it. Looks like it was a problem in the joystick configuration. I'm not sure why it was working in the menu and not in the plane, but it does appear to be working correctly now.

 

I think mostly I am just relieved to find out it was actually a controls problem and not that I'm incompetent or going mad somehow :p

 

EDIT 2; Yes, it's fixed! And this is so much better. Having the plane trimmed correctly really does make a huge difference. Of course, now I need to unlearn a bunch of bad habits I developed when I didn't have it trimmed right, but at least I will be learning it correctly now.

[IronMike]

Glad you could fix it!

 

Here, take a look at this vid, maybe it helps you with the habits a bit. Note it was a super quick recording so I brabbled some nonsense in between, I noted all the mistakes I made in the description, please read it to get the correct impression.

 

[F1GHTS-ON]

As another pilot that struggles with trim for On-Speed, can I highlight my cheat (& probably demonstrate my complete ignorance of F-14 systems). My "cheat" is to temporarily engage the Auto Throttle on the downwind leg, this puts the aircraft "on speed" and seems to trim the aircraft correctly. With a shortcut key mapped on throttle, I can now dis-engage the auto throttle and fly the remainder of the pattern with the F-14 apparently trimmed correctly. (or really lazily fly the rest of the groove using DLC and fore & aft stick movements in auto throttle)....

 

My question is: Does the use of auto throttle cause the aircraft to trim automatically (like altitude hold does)?

[Baz000]

Alot of people just don’t understand how trim works or can even trim any simulated non FBW aircraft properly... Let alone a F-14.

 

Trim itself for people with no background in aviation is a foreign concept entirely. And in general, DCS training missions never covered trimming any aircraft as a concept for the player to learn controlled level flight or climb or dive at a constant rate.

 

Something in the future that should be rectified by some in cockpit training missions.

 

Or for that matter, how changes to the aircraft configuration like speedbrakes, deployment of DLC or flaps changes the trim conditions.

 

This is something that is a general problem in DCS, especially because unless you have force feedback stick, you can’t feel the changes of force control stick that trim removes, so then we are relegated to looking for visual cues to changes which isn’t as instinctual as seat of your pants feel of flying.

 

Just another limitation we need to learn how to contend with.

[Wildwind]

Alot of people just don’t understand how trim works or can even trim any simulated non FBW aircraft properly... Let alone a F-14.

 

Trim itself for people with no background in aviation is a foreign concept entirely. And in general, DCS training missions never covered trimming any aircraft as a concept for the player to learn controlled level flight or climb or dive at a constant rate.

 

Something in the future that should be rectified by some in cockpit training missions.

 

Or for that matter, how changes to the aircraft configuration like speedbrakes, deployment of DLC or flaps changes the trim conditions.

 

This is something that is a general problem in DCS, especially because unless you have force feedback stick, you can’t feel the changes of force control stick that trim removes, so then we are relegated to looking for visual cues to changes which isn’t as instinctual as seat of your pants feel of flying.

 

Just another limitation we need to learn how to contend with.

 

This has a lot to do with why it took me so long to realize it was a controls problem. I couldn't reliably perceive whether the clicking the trim hat (actually an analog stick mapped as a hat, which was where the problem was - I needed to recalibrate the underlying analog axis) was making a difference or not. It was only when I tried it sitting on the ground and realized that when I trimmed nose-down, the stabilators moved, and when I trimmed it nose up, they didn't, that I realized it was actually broken.

 

Of course, now that I have it working correctly, I realize that it should have been obvious it wasn't working, now that I have actually seen it at work and understand better how it affects the aircraft (it's one thing to understand it intellectually, and something rather different to actually experience it).

 

Glad you could fix it!

 

Here, take a look at this vid, maybe it helps you with the habits a bit. Note it was a super quick recording so I brabbled some nonsense in between, I noted all the mistakes I made in the description, please read it to get the correct impression.

 

 

Thanks, this is quite helpful.

 

One thing I realized is that I have no business trying to land on the boat until I can consistently fly the pattern and land correctly at the airfield. So tonight I spent a fair amount of time practicing at the airfield and I am beginning to get a handle on controlling the aircraft on-speed. So much of it is learning how to recognize (and then anticipate) the need for throttle changes.. It was only tonight that I finally put together that if I am experiencing dutch roll, it's because I'm too slow (and therefore my AoA is too high). But this is something I could never have put together until I got the aircraft trimmed right - before that, I was so busy fighting the stick I couldn't properly establish the relationship between AoA and speed in anything beyond an intellectual sense. Now that I see it in practice, I have finally started actually learning.

 

For the first time tonight, I actually landed the aircraft at the correct speed, AoA, and descent rate, several times. And once, I even set her down exactly where I wanted to. Now, I just need to be able to reproduce that consistently, and then I'll be ready to try my hand at the boat again.

 

[Baz000]

There are some good resources on understanding trimming an airplane if you know what to look for but here is an example:

 

 

https://www.cfinotebook.net/notebook...g-the-aircraft

 

F-14 Specifics:

 

1. You have no Trim wheel, the trim is A 4-way momentary China HAT on the top of the stick in the F-14... You have nose up, down, and wing left and right

 

2. If your wings are actively changing sweep, consider this a configuration change and you need to adjust your trim... Generally as the wings sweep back you need more nose up trim, and vice versa when they sweep forward.

 

3. The F-14 has no Trim tabs, the entire stab moves when you fool with the Trim, so don't over do it with the Trim inputs it will have more responsiveness than your Cessna 172 with trim tabs. Give a Trim input and watch for the effect it has, correct as needed.

 

4. Follow this as a basic guide

• Pitch-Power-Configuration-Trim
  
• You are working to trim for an airspeed!
  
• If you are changing your airspeed in any way then your trim will be off
  

Entering/in the downwind:

 

Pitch- this should be level flight in the F-14 at 600 ft AGL (above ground level)

Power- this should be set to maintain level flight at 600 ft AGL

 

The combination of Pitch plus Power = your current AOA, the goal is to manage both of them so you arrive at 600ft AGL in level flight at on speed AOA (yellow donut on AOA indexer)

At a certain point as you reduce speed and approach what is called the power curve, basically your controls become reversed and now you pitch for speed and power for altitude. So, in other words your nose pitch position is controlling your approach speed which the goal is to maintain onspeed AOA of that yellow donut in the AOA indexer. Excursions out of that will primarily be controlled by your nose up or down positioning.

 

next, the power you are giving to your engines in this particular flight regime is going to control your decent rate and rate of climb or if you are level. This is very unusual because normally your nose pitch is controlling this and your power is controlling your airspeed. But in this particular flight regime, these two things basically become reversed.

 

Pitch + Power still in this flight regime will have an input into your AOA, but not as drastically as only lowering or raising your nose will. The power inputs take time to develop to change your AOA compared to the more immediate effect that the pitch inputs provide. So for example if you keep your pitch the same and give it MIL power from a level flight state at onspeed AOA... The first thing you will notice is you will start to rapidly begin a climb and the next thing is you will not be at the same onspeed AOA if you don't change your nose pitch position to compensate for the increased thrust. Your AOA will go past onspeed and you will build speed in the climb showing a Red upside-down V.

 

Configuration- this should be speedbrakes deployed, wings sweep to AUTO, landing gear down and locked, Flaps fully down, DLC deployed

 

each of these points changes the configuration of the jet, my advice is to wait until fully configured before messing with the trim otherwise you will be chasing your own tail with every change... And each of these configuration changes will cause the jet to experience more drag, thus helping it to slow down to onspeed AOA.

 

TRIM- once your pitch and power and configuration are all set... Go ahead and work the trim for holding the nose at onspeed AOA with the yellow donut. More than likely, if you entered the overhead break with your wings swept at 68 degrees, you also trimmed to hold that... So as you get onto downwind, that is the current trim state of the jet, and you will work the nose up trim until you get that yellow donut...

 

While you do that it is a bit of a balancing act that takes some practice because you need to manage your power to hold your jet level at 600ft AGL as well... Give a trim input, see the result... Too much trim input given? Chip some of it away... Too little trim given? Add some more, the key here is you will know your managed everything correctly and trimmed the aircraft when you are fully configured for landing, at onspeed AOA with the yellow donut and holding level flight at 600ft AGL.

 

Just remember if you make any change to your PITCH or POWER or CONFIGURATION then your trim needs adjustment.

 

At a certain point after enough practice and repetition, this will all be instinctual and done by you with little need for the grey matter between your ears having to give it much thought.

 

Oh, and this was only with the Elevator trim in mind... But similar principles apply to the aileron and rudder trim... I think it goes Rudder trim first, then Elevator and then Aileron. In that order primarily in general aviation aircraft IIRC.

 

Trim Procedure:

• Trimming the aircraft allows for the relief of control pressures to stabilize the aircraft
  
• Rudder trim is the most common on general aviation
  
  • Rudder is trimmed right for power increases and slower airspeeds
    
  • Rudder is trimmed left for power reductions and higher airspeeds
    

  [*]Elevator trim:

  • Elevator is trimmed up for power reductions and slower airspeeds
    
  • Elevator is trimmed down for power additions and higher airspeeds
    

  [*]Aileron:

  • Used as required to level an aircraft
    

  [*]Trim Tabs:

  • Servo: trim tab moves opposite of the surface it is trimming
    
  • Anti-Servo: trim tab moves with the surface it is trimming
    

[Wildwind]

Trim Procedure:

• Trimming the aircraft allows for the relief of control pressures to stabilize the aircraft
  
• Rudder trim is the most common on general aviation
  

 

Yeah, rudder trim is heavily needed in warbirds, too. Example, in the P-51 you have to trim something like 6 degrees right rudder on takeoff, and then you'll be adjusting that immediately once you're in a stable climb.

 

I find in the F-14 the only time I ever touch the rudder trim is when I extend the fuel probe (the extra drag from the probe on the right side causes the aircraft to yaw right, so I have to add a fair bit of left rudder trim to compensate). Is there any other time I ought to be using it? The aircraft seems to fly naturally straight without any intervention on my part (possibly this is the effect of twin engines/twin rudders).

 

Actually, logically, it occurs to me that I should probably be trimming rudder after firing a missile from one side or the other (for the same reason, except in this case I've reduced drag on one side), but I am usually too busy in those moments to pay much attention to that.

[Dragon1-1]

When flying in an asymmetric configuration, you trim ailerons, not rudder. In general, jets don't require rudder trim at all in normal flight, because they don't have propeller torque effects. On a jet's HOTAS, there's pitch and roll trim, and yaw, if present at all, is relegated to some knob in the back of the cockpit. If you have an offset fuel probe, or are flying on one engine in a twin engine aircraft, then you may need this knob to trim this out (unless it's EE Lightning, in which you trim pitch instead).