Are there any existing (space)plane landing tutorials?

[Wanderfound]

My impression is that spoilers substantially enhance braking on the ground, but I haven't actually run a comparison test on it. I'll do a back-to-back test with spoilers on or off later and report back.

[EdFred]

Flaps are the opposite of spoilers. They increase lift, so make the glide path flatter, and allow planes to remain flying at lower speeds, than their wings alone would allow. High speed planes typically don't have much wing because lift is a function of speed so they get all they need by going fast, and having more wing would created drag and not let them go as fast. But they still have to fly slow at takeoff and landing, so they use flaps to fool the air into thinking they have big wings when flying slow.

The bold part is incorrect. Flaps do increase lift (and drag), but they also increase the ascent/descent path without increasing forward velocity. They do allow planes to fly at lower speeds, but they do not flatten the glide path. There's a reason we use flaps for short field take-offs and landings with obstructions - and it's certainly not to come in flat. You want to come in flat, leave the flaps undeployed.

[Jovus]

So then do both flaps and spoilers steepen the glide angle?

[EdFred]

So then do both flaps and spoilers steepen the glide angle?

Spoilers and flaps both make the airframe "dirty" or increase drag. Increased drag means a steeper approach path for the same forward velocity. Spoilers decrease lift and increase drag, while flaps increase lift and increase drag. Spoilers used in flight are generally used at higher speeds, and flaps at lower speeds. Many, if not all, airplanes have a maximum flap speed which is lower than the maximum spoiler speed - if the plane is equipped with spoilers. Once on the ground spoilers increase the weight on the landing gear, which helps in braking.

Edited August 21, 2014 by EdFred

[Alshain]

Get a plane on the runway and do some pre-flight checks. Watch the spoilers deflect upward, above the wing. The flaps deflect downward below the wing. Deflecting the air above the wing creates downforce. Deflecting the air below the wing will create more upforce or lift.

[Geschosskopf]

The bold part is incorrect. Flaps do increase lift (and drag), but they also increase the ascent/descent path without increasing forward velocity. They do allow planes to fly at lower speeds, but they do not flatten the glide path. There's a reason we use flaps for short field take-offs and landings with obstructions - and it's certainly not to come in flat. You want to come in flat, leave the flaps undeployed.

What I said was correct in the right context . The reason you use flaps for short-field stuff in light aircraft are 1) they're all you've got and 2) due to the plane's relatively low stall speed and low wing-loading even without flaps, the flaps also function as airbrakes. So yes, in light aircraft, they will steeping your glidepath without letting your speed increase. However, I was talking about big, heavy things with high wing-loading, such as your typical spaceplane. Without flaps, their stall speed is so high they have to down steeply just to maintain flying speed. With flaps, they can fly slower, so don't have to descend as steeply to get the same amount of lift, so they end up with a flatter glidepath.

[EdFred]

What I said was correct in the right context . The reason you use flaps for short-field stuff in light aircraft are 1) they're all you've got and 2) due to the plane's relatively low stall speed and low wing-loading even without flaps, the flaps also function as airbrakes. So yes, in light aircraft, they will steeping your glidepath without letting your speed increase. However, I was talking about big, heavy things with high wing-loading, such as your typical spaceplane. Without flaps, their stall speed is so high they have to down steeply just to maintain flying speed. With flaps, they can fly slower, so don't have to descend as steeply to get the same amount of lift, so they end up with a flatter glidepath.

In real life no one (ok, maybe 1 person, somewhere might) uses them in that manner, though.

[NecroBones]

I haven't read all of them, but there are lots of really good answers in this thread. So I'll only say this:

1. Line up with runway as far out as you can, and fly low in the approach.

2. Make sure your vertical (not forward) speed is as low as you can get it.

For point #2, I like to keep the prograde marker on the navball right on the horizon, when I'm only 100-200 meters up (or a little below if I'm higher than that), until I get to the runway, and then let the prograde marker drop slightly. I do this with throttle set low (maybe around 1/3), and cut it shortly before reaching the runway.

See screenshots: (last pic I'm going almost horizontal, as I accidentally slowed my descent more than I meant, with all my fuel mass gone, so I used more runway than needed)

Edited August 21, 2014 by NecroBones

[EdFred]

Bill, keep your eyes on the runway!!!

( I love that in the screen shots, he's looking elsewhere)

[Alshain]

I'll tell you what though, it sure would be nice if the KSC runway had a PAPI system.

[soulreaver1981]

just go as fast as you can and hit the ground

[Wanderfound]

What I said was correct in the right context . The reason you use flaps for short-field stuff in light aircraft are 1) they're all you've got and 2) due to the plane's relatively low stall speed and low wing-loading even without flaps, the flaps also function as airbrakes. So yes, in light aircraft, they will steeping your glidepath without letting your speed increase. However, I was talking about big, heavy things with high wing-loading, such as your typical spaceplane. Without flaps, their stall speed is so high they have to down steeply just to maintain flying speed. With flaps, they can fly slower, so don't have to descend as steeply to get the same amount of lift, so they end up with a flatter glidepath.

Not really my experience.

My spaceplanes aren't small, and I prefer small-wing delta designs. But they'll glide quite happily at speeds only a little over 100m/s, and I usually come into the runway virtually flat from treetop level.

Possibly the SP+ lifting bodies that I tend to use are helping me out here.

[Jovus]

I do-ed it! I do-ed it! From space and everything!

Well, not quite. I overshot by a huge amount (about 1/5th of the the planet) and had to circle back around and cross an ocean, but my final approach was perfect, and I touched down in the first third of the runway, and applied the brakes...and then picked up some strange yaw from them and flipped over sideways and exploded. But! That totally counts. It just means I need to quicksave right before landing. (I don't feel quicksaving with aircraft is verboten, though I avoid it with rockets.)

[Wanderfound]

My impression is that spoilers substantially enhance braking on the ground, but I haven't actually run a comparison test on it. I'll do a back-to-back test with spoilers on or off later and report back.

Okay: ran the test.

Took the same plane out on the runway twice, once with all control surfaces except the advanced canards set as spoilers (which is how I normally have it), once with no spoilers. Fired them up, killed engines and hit brakes at the same spot. The spoilered one stopped about ten metres earlier. FAR in operation.

Not a huge amount, but not totally trivial either.

Edited August 22, 2014 by Wanderfound

[Wanderfound]

I do-ed it! I do-ed it! From space and everything!

Well, not quite. I overshot by a huge amount (about 1/5th of the the planet) and had to circle back around and cross an ocean, but my final approach was perfect, and I touched down in the first third of the runway, and applied the brakes...and then picked up some strange yaw from them and flipped over sideways and exploded. But! That totally counts. It just means I need to quicksave right before landing. (I don't feel quicksaving with aircraft is verboten, though I avoid it with rockets.)

Yay!

Kinda...

For the yaw: had you remembered to unlock the steering on your front gear when you were building it?

If it was the Benchmark, the steering should be unlocked unless you messed with it. Was the SAS on?

Edited August 22, 2014 by Wanderfound

[Jovus]

Yep, I figure it was the SAS trying to maintain a fractional roll angle. It was indeed the Benchmark, because a blind dog can get that thing to space.

[Wanderfound]

Yep, I figure it was the SAS trying to maintain a fractional roll angle. It was indeed the Benchmark, because a blind dog can get that thing to space.

With the spins on reentry, did you quickload or recover? What were you doing with the controls, throttle etc when it happned?

[Jovus]

Spins on re-entry? I haven't yet spun out on re-entry.

As for the controls on touchdown, the only thing I was touching was the brake, but I probably did have a small sideslip angle; SAS likes to fly that thing with a sideslip around 0.6 degrees, I've noticed. The throttle was next best thing to off.

[peadar1987]

I find the yawing and general explodiness is caused by too much weight on the narrow front wheel. Have you tried disabling the front brakes? I found this works much better for me on my few successful landings

[Javster]

Now that you can quicksave while flying (most of the time, if the game is feeling happy when you try) you should fly your approach, get within, say, 1km from the runway, and practice landing. If you crash, just F9.

[Geschosskopf]

I do-ed it! I do-ed it! From space and everything!

Well, not quite. I overshot by a huge amount (about 1/5th of the the planet) and had to circle back around and cross an ocean, but my final approach was perfect, and I touched down in the first third of the runway, and applied the brakes...and then picked up some strange yaw from them and flipped over sideways and exploded. But! That totally counts. It just means I need to quicksave right before landing. (I don't feel quicksaving with aircraft is verboten, though I avoid it with rockets.)

Very good!

Be careful with the brakes. It's really only safe to use them when all wheels are on the ground. If you use them while you're still bouncing, only 1 will be touching the ground usually so you get an asymmetrical force which causes you to get sideways. Also, you need to have the wings be as close to parallel with the ground surface as you can get them. The landing gear themselves and the airframe have some flex in them so even though all wheels are on the ground, the plane can be rolled slightly 1 way or the other, putting more weight on 1 wheel. The more downforce on a wheel, the more effective its brake, so again you can get asymmetrical braking force and potentially deadly yaw.

So all in all, unless you'll surely die unless you stop RIGHT NOW, it's often better to wait to brake until you've quit bouncing and have let any slight amount of roll work itself out (briefly toggling SAS with the F key can do that). Or if you have to act fast, to tap them repeatedly only when it looks like you're level and all wheels touching, until things settle down. Then you can hold them down. Just be sure you don't somersault from using too much nosewheel brake. I usually disable the nosewheel brake in the SPH to avoid this.

[Pecan]

I'll tell you what though, it sure would be nice if the KSC runway had a PAPI system.

There's a mod for that.

Alternatively, Nav Utilities adds HSI and VSI in a popup window or, with RPM, in IVA

[Wanderfound]

Spins on re-entry? I haven't yet spun out on re-entry.

As for the controls on touchdown, the only thing I was touching was the brake, but I probably did have a small sideslip angle; SAS likes to fly that thing with a sideslip around 0.6 degrees, I've noticed. The throttle was next best thing to off.

Sorry, got mixed up with what someone else posted.

Not sure about the landing thing. You do often need to do a bit of (very gentle) steering during touchdown, though.