Maximizing performance in Hurricane.

[Itkovian]

Salutations,

I've recently obtained CloD, along with the Wicks vs Dundas module from Desastersoft, and I've been having something of a bother trying to keep up with my squadron when flying formation while flying a Hurricane (with the 2-speed prop).

Basically, in those missions you fly as a section leader, and I have been trying to stay in formation, but invariably I find myself having to push my throttle to the max to keep up (and so overheat the engine). This is while the squadron is slowly climbing up to 10 000'

Now I assume this is a combination of Complex Engine Management settings and Trim, but I cannot find any guide on how to get the best out of my Hurricane and keep up with the AI without overheating the engine.

Generally, when trying to keep up I fly with prop pitch set to fine, radiator medium, mixture medium or rich (if I try lean, engine starts stuttering). The only way I can keep up is by pushing the engine, and that starts raising my oil and radiator temp too much (if I weren't trying to keep formation, I'd try and maintain 2400 RPM).

So anyway, some assistance on how to maximize my hurri's performance would be appreciated. I assume trim plays a major role, but cannot find a guide on it.

Thank you.

Itkovian

[trademe900]

Sorry, this is a bug that has been around since il2 1946. The ai have perfect trim and engine settings and they can always go faster than you. Also, the AI engines don't even overheat, at least they didn't in il2 1946 until the recent patch.

[SEE]

Jump in your plane and let an AI pilot fly it by pressing A - (AI control must be enabled in Realism settings) you will soon discover why AI pilots are quicker.....:grin:

[Itkovian]

Allright, so they have perfect trim... but what trim is that?

Some general guidelines on how to properly trim the hurri mk 1 would be appreciated.

Thank you.

Itkovian

[Blackdog_kt]

Trim is generally situational, there's no perfect trim for all conditions.

To trim an aircraft, first start with elevator trim and decide on one of two things: the climb rate or the speed you want it to achieve when flying (almost) hands-off.

Because airflow (and thus lift) over the wings is affected by your airspeed (your speed relative to the speed of the air outside), changing one also changes the other.

From here on there's some counter-intuitive stuff happening because for most people elevator trim raises or lowers the nose, but it helps to think of it in the following way.

What elevator trim essentially does is tell an airplane to fly a certain airspeed. If it can't, it will either stall (if you tell it to fly too slow) or raise the nose (if you tell it to fly too fast). Conversely, if your speed changes for whatever reason, the aircraft will raise or drop its nose to compensate and keep at the speed trim tells it to fly.
This might result in your aircraft climbing or losing altitude, but the plane doesn't care. All it cares about is keeping to the airspeed dictated by elevator trim.

So, trim nose up (slower) or nose down (faster) until you achieve the speed you want. Climb is then a byproduct of speed and leftover engine thrust: if you increase power the plane will raise the nose to prevent an increase in speed and you will climb, if you decrease power the plane will lower its nose to prevent a speed decrease and you will descent.

It's pretty similar to how we've been told to think during approach and landing, ie "nose up/down governs your speed and power governs your climb/sink rate".

Various scenarios are then possible and with some experience, you will be doing it so naturally that you will know both the limits of your aircraft and what changes to expect in both airspeed and climb rate due to a trim change.

So, once you have finalized your elevator trim for the power setting, speed and attitude you want to attain (eg, a modest climb of 500 feet per minute at cruise power and a speed of 220mph, or a gradual descend at 500 per minute with low power and a speed of 200 mph), you can focus on the rest of your trim surfaces.

The reason you take care of elevators first is that they tie in with power and power affects sideslip. Without going into too much details, that rotating propeller in the front adds both a rolling and a yawing component to how the plane moves through various phenomena (rotating airflow hitting your vertical stabilizer, gyroscopic torque, yaw affecting roll, etc). So for example, if you trimmed your rudder before finalizing your climb/speed/power trim with your elevators, you would have to redo your rudder trim after adjusting power. That's the reason you first adjust elevator and then rudder.

With the rudder things are pretty simple. Just adjust left/right until the sideslip indicator reads zero.

Of course simple doesn't mean trivial. As soon as you trim your rudder properly your aircraft flies straight, nose-on through the air, whereas before it was flying at an angle that exposed part of the fuselage to oncoming air. You were flying with extra drag before, which you now don't have anymore. As you can guess, lack of resistance means an increase in speed and since our elevator trim wants to keep speed steady, the nose will rise and you will climb.

So, a minor adjustment in power and/or elevator trim might be required to bring it all back to level.


Finally, ailerons are the last to trim. It is often the case that once you trim everything else, you will notice that you are rolling off to one side. This is both due to the propeller effects as well as the rudder being deflected slightly (because you trimmed it and it's now sitting off-center) and causing a bit of roll. So, just trim ailerons left or right until you zero that one out.

Once again, this might change your sideslip a bit and require a touch of rudder trim correction.

Overall this is the process. Don't be daunted however, because it takes much longer to describe and read/understand than it takes to practice and apply it. Good trim is an essential skill that few virtual pilots master to a high extent, but the majority are able to learn to a satisfactory level.

Last but not least, depending on your aircraft choice you might not have all 3 axis of movement equipped with trim controls. Some aircraft lack aileron trim (most if not all of the RAF ones), some lack rudder trim (like the 109), etc.

In that case you do one of the following.

-Compensate with actual control inputs: You can't really fly hands-off.

-Stick to the airspeed for which the missing control is pre-trimmed by the manufacturer: Ailerons in RAF aircraft have a bit of built-in trim that corresponds to their nominal cruise speed, flying that airspeed will require no aileron adjustment. Similarly, the 109 rudder was adjustable by the ground crew before take-off and trimmed for a specific airspeed.

-Fly a bit inefficiently: If you want to fly faster than the built-in trim allows on the non-adjustable surfaces and you still don't want to fight the controls all the time, it might be good to compromise. For example, flying a Blenheim with correct rudder trim induces a bit of roll. If you slightly move your rudder trim away from optimal so that you get a bit of sideslip, it will prevent it from rolling. You lose a bit of speed in the process, but you don't have to fight the stick forces all the time.


Hope it helps. Generally speaking, if you have a bit of an idea on how things work it's easier to test it out for yourself and gain experience. ;)

[McFeckit]

Thanks Blackdog, that was very clear and well written. Certainly a penny dropping moment for me anyhow.

[ATAG_Snapper]

Thanks Blackdog, that was very clear and well written. Certainly a penny dropping moment for me anyhow.

+1

For the RAF fighters I have trim mapped to two of my CH Quadrant axis which work very well. Through trial and error (mostly error, at first) I gradually learned the trimming techniques which Blackdog so clearly explains above. It's good to know WHY the trim works as it does.

Thanks for posting this, BD.

[Blackdog_kt]

Glad to help out.

If any of you guys find such posts useful, feel free to quote them on your own squad/server forums and compile them into guides.

I would sit down and probably collect them myself for a new "how to" sticky, but i'm a bit busy lately and i prefer to spend my free time flying :-P

Another reason is that i'm waiting until a couple patches down the line. I expect that when the graphics patch goes official, they will then probably move to correcting the errors in how certain systems are modeled.

It would be too much work for nothing if i sat down to make a guide that covers everything, including workarounds for bugs that are probably next in line to get fixed.

Once the majority of these issues are sorted out, i'll probably open two sticky threads for how-to stuff like this.
First, one thread to discuss and let the community suggest procedures, post their test results and so on, so that we can find what works and how.
Second, a thread that will be a compilation of what we managed to find out in the first thread. The second thread will be locked and i will be probably updating it once a week or so.

This lets us have a place to discuss things and come up with solutions, while at the same time if anyone just wants the instructions he can go and look them up in the locked thread.

For this to happen though, we first need to see most of the systems modeling errors being corrected.