Combat flight sims (esp. IL-2) - how to use flaps well?

Thirith on 6/8/2018 at 07:15

I don't know if there are any big sim experts here - well, there's henke, but I think he's more into things that mainly drive around in the mud. Anyway, I got started on IL-2: Battle of Stalingrad, mainly because I wanted to check out a WW2-era flight sim that works in VR. There's tons of stuff I have to learn, and IL-2 isn't exactly the most beginner-friendly sim, but I've found useful videos on most aspects of the game.

However, what I haven't found is anything on flaps. I get the general physics behind them (I think) - lowering flaps means more lift and more drag - but I don't really know when to use them and to what extent it differs from plane to plane. Are there general rules of thumb with respect to when to use flaps?

I'd also be very receptive for other tips on how to survive IL-2, but it's mainly the flaps issue that I wouldn't mind having resolved. Cheers!

Neb on 6/8/2018 at 08:27

Have your flaps down when taking off so that you can get as much lift as possible, and then flaps down too for landings so that you can come in slow and steady. During mid-flight just keep them level to stop the drag. I can't think of any other time when they're really worth worrying about.

Thirith on 6/8/2018 at 08:49

Cheers. So far I've only done a couple of take-offs in the YAK-1 without touching the flaps at all, but I definitely had the impression that the plane was somewhat sluggish in getting off the ground.

Of course my biggest problem so far is that you barely see any of the runway when seated in the cockpit of one of those planes; you see the propeller and nose and the rest is measly peripheral vision. Makes me wonder how anyone ever got in the air in one of those crates.

Trance on 6/8/2018 at 13:57

While taxiing in one of those long-nosed aircraft, you can zig-zag slightly to see what's directly ahead.

Thirith on 6/8/2018 at 14:06

Would I do that while the tail wheel is locked, using the rudder only?

caffeinatedzombeh on 6/8/2018 at 23:14

You only want it locked when you're trying to go in a straight line, as I understand it you'd steer with the brakes mostly on that sort of thing but it's not something I've any experience of as I prefer to be able to see where I'm going.
The same principle applies to climbing in anything that goes quite nose high, you want to occasionally move the nose out of the way and check you're not going to fly into anything (or in this case that there's not someone unpleasant hiding under it)

All aircraft are different, even two the same. Flaps can have pretty much any effect from being little more than decoration through to 500ft/min changes to climb rate if you leave the nose where it was and 15 degrees of yaw because you were expecting it to stay in a straight line.

Depending on how complicated your flaps are you generally want one stage of flap for landing and takeoff on a sensible length runway, past a certain point all you're doing is adding drag so a lot of modern aircraft allow the flaps to go way past the point of adding useful lift to make it possible to get into a really short field (you need to add a load of power to keep it in the air like that but you can come in slower doing it).

Climbing out retract the flaps once you're at whatever's a sensible speed for the aircraft (somewhere between as soon as practical and before they break off), pull the stick back a little as the flaps come up to keep the climb rate about the same, the airspeed will then build up as you've dumped a whole load of drag and you can put it back where it was.
For landing as you're slowing the aircraft down bring the flaps in as soon as you get down to a sensible speed and they'll help you slow down. Though you'll quite possibly have to push the nose down as you do it to stop you going waaaaaaay up the air.
Ideally the maximum speed for flaps will be marked on the ASI

catbarf on 7/8/2018 at 19:41

Depending on the plane, lowering flaps slightly can also have some application in combat. More lift can be beneficial in a knife-fight to tighten your turn radius, and can help avoid stalling at very low speed. On the flipside, the extra drag further reduces your energy, so you can wind up in a disadvantageous position if your opponent is able to maintain energy better. It's worth experimenting with.

heywood on 7/8/2018 at 21:34

I would think you could achieve a tighter turn radius for the same energy loss by increasing elevator angle versus adding flaps. Can't say I've really tried to use flaps in combat though. They extend and retract slowly, so I've never even tried incorporating them into a tactic.

demagogue on 7/8/2018 at 23:13

As you get to know a plane, you get a feel for its limits in terms of turns, speed, lift, and when you reach the stalling point. The plane will start balking if you push the limits. So the shorthand description is that flaps nudge those limits, you get tighter turns and a lift bump at lower speeds and you won't balk or stall, and it's a speed drain. You should pick a plane that you want to learn and run through a diagram of maneuvers, and then do them with the flaps on. All that said, I've been playing IL-2 since like 2006 and I still get my ass handed to me, so what do I know.

Thirith on 8/8/2018 at 07:27

Thanks, guys. Lots there that is helpful.

From what all of you've written, my impression is that IL-2 doesn't really lend itself to casual players but requires much more of a commitment. Perhaps I'll be pulled in by the game, but seeing how I mainly want to play it in VR, which means I'd play perhaps 4-5 hours a week, I probably won't get to know the planes very well. Perhaps I should just stick to take-offs, landings and shooting down the occasional bomber. :p