Question Runway landing

[downloaderfan]

Ok,just a day ago i learnt to re-enter and align with the base,since then i have been doing this for mars,titan,earth.Well,mars and titan had pad landings so they werent a problem.

But no matter how many times i try to land the XR2 in the runway at earth,most of the times i fail to align it with the runway or i crash with a very high vertical velocity.Problem arises when i am not lined with the runway while approaching it.
I tried to do HAC but im not able to do it since i dont have a joystick.(I guess?)

So i tried for almost an hour to follow glidescope as it is from a certain scenario,but i succeeded only like 6-7 times out of all those.I dont understand much aerodynamics so i am now wondering if im missing some kind of knowledge or is it just that i need a joystick?

As a lot of u people out there have a very good experience of landing on runways,i thought i should confirm this doubt of mine with u guys.

Thanks for the help.

 

[PhantomCruiser]

In the real world, take-offs are optional, but landings are mandatory...

Take a look at Oceanics reentry tutorial here ->http://orbiter-forum.com/showthread.php?t=8425
It was very helpful for me, it'll get you very near where you need to be. Another thing is knowing the airstrip that you are landing on. For instance, Wideawake's runway runs 120 degrees. If your reentry path is running nW to SE, you are not that far off the runway, a small tweak will put you right along the center. If you are appraoching SW to NE, then you will need to do a HAC turn (or overfield break) to line up.

With the DGIV and XR-fleet you can always just use your engines and do some atmospheric flight to line up on runway heading, with a shuttle you need to be more precise (unless you are using autoFCS, then it's hands-off).

Keep practicing, the skills you need will develop, it just takes time.

 

[worir1]

I made a video on how to land the XR2 using basesync and aerobrake MFD. Hope it helps.

http://youtu.be/pviuLdlyHEA

 

[ADSWNJ]

Use Glideslope 2.2 MFD. It will guide you down the main descent from space to the terminal area energy management zone, then guide you around the HAC turn, and finally the outer and inner glideslope to landing. There's also a full landing walkthrough in the docs too.

 

[edjohnbus]

i too do not have a joy stick, I get my TAS below 250 and autohover from there onto the runway. I know, it's not any help, but I like this thread because I really do need to learn how to actually land.

 

[Cras]

Are you doing this deadstick?

If you are trying a deadstick landing, do not follow the ILS thing that is in Orbiter, that is way to shallow a glideslope for such an approach, you need to come in much much steeper.

I would not recommend landing a spaceplane without a joystick, but maybe you can follow how I do it with numpad anyway.

Use your velocity vector indicator, it will serve you well. I dont know what the default in-client looks like anymore, but in D3D9 there is the approach indicators way forward of the runway. Point your velocity vector at those things, deploying the speedbrake if warranted, target velocity here is about 130-150 m/s.

Upon reaching 800 meters above the ground, flare up and put the velocity vector on the TDZ of the runway, retract the speed break, let the speed fall, target landing speed is 100-120 m/s

at 600 meters drop the gear, keep flaring up, maintain the velocity vector on the TDZ, and you will find your v/s continues to fall and you will fly a positive landing right where you want to be.

This is how I land the Xr-2, grease the thing every time.

 

[PhantomCruiser]

A joystick isn't essential. I went for years without one, then when I started using one I had to learn to fly all over again.

I'd shy away from relying on landing with hover engines, it could cause you some trouble when you are bringing in the shuttle and you want to use engines that are not even there...

I can maybe post a few scenarios for you that have the XR-2 in diffent stages of approach (like short final, base turn, etc) or (even better), just get in the XR-2 on the runway, take off and do racetrack patterns until you can get your visual cues.
Meaning, take off. Climb to maybe 4-5 Km in altitude and make a lazy 180 left (or right) turn and continue a shallow climb. When you are about even with the center of the runway, reduce power for a shallow glide. Coast "downhill" and make your base turn (90 degrees) the hold that to turn onto final. Take this time to practice lining up on runway heading and either glide in, or hold on to power for a go-around. Real pilots do this for practice (in the NAVY we called it DFW for Dedicated Fuel Waste), but they are better known as touch and go's. The more you practice the better you'll be.

Like Cras mentioned, the velocity vector is your friend, put it where you want to be. Airspeed and altitude management will come with practice.

Don't feel bad about missing the runway, if you dig around on the forum's you'll see that there is a virtual pile of crashed spaceplanes off the runway from WideAwake. I didn't learn to bring in the Shuttle until about 2 years ago, but after many years of practice, I can dead stick a DGIV or XR-x onto any runway of my choice. Don't get discouraged, practice instead.

 

[4throck]

One thing that works when going too fast is to do some 90º "s" turns before reaching the runway.
A Joystick will certainly help here.

 

[downloaderfan]

Allright guys,thanks for all the quick replies,after following this thread and after hours of practicing more,i am now able to land the XR-2 successfully 90% of the times on the runway. Here's what i do
I'm in a scenario,approaching wideawake from ksc,at a distance of 100km from the runway and a speed of nearly mach 4.

When i can clearly see the runway from the pilot seat,i bank towards the base and pitch up to turn in the direction of the base.Then i bank in the opposite direction and pitch up to get a better alignment.By doing this 2-3 times i get perfectly aligned with the runway.
When im just a few kilometers away from the base,i pitch down to point my velocity vector just short of the runway(taking care of the altitude) and do some final adjustments.At about 1500 altitude,i deploy gear and begin gradually pitching up to reduce my vertical speed and then finally land.

A few things that i would like other people who are still learning to know(Some of them have already been mentioned here by others)
1)When u are just few kilometers away from the runway,check ur TAS,if its above 200m/s,deploy airbrake till its about 150m/s.Dont let TAS fall too low(<100) before landing otherwise i've found that it reduces the lift and increases the vertical speed during landing and increases the possibility of a gear failure.
2)Its difficult to eyeball if ur perfectly with the runway,mostly i am off lined by a very small amout when im just about to touch the ground,in such cases i use glideslope to actually land on the runway and then make some small changes to stay inside the runway.
3)I tried to do HAC many times using glideslope with no improvements,so i concluded that its not possible to do a clean HAC without a joystick.As long as im able to land on runways using the technique mentioned above,i dont need to bother about it.(i guess?)
4)I found out that keeping the rotational thrusters on gives a better control during landing,reducing the risk of a gear failure.

Thats all from a newbie,thanks to all the people from this thread for giving me encouragement and tips for the landing procedure cuz of which i now enjoy executing the landing procedure.

Special thanks to ADSWNJ for making glideslope MFD,it surely has made things quite a lot easier for me and countless other people who have made other addons which has made things in orbiter quite easy.And of course martin and his team for making orbiter.

Any more suggestions are always welcomed.

And of course

 

[ADSWNJ]

Original credit for Glideslope should all go to Chris Jeppesen (kwan3217). I was working from an awesome base in Glideslope 1, but I added quite a few features in Glideslope 2.x that help with controlling a landing like this.

On the HAC - I have never flown it with a joystick, so I can say for sure it's flyable off the keyboard. I made the size and orientation of the HAC adjustable to allow you to do adjustment according to speed, energy and angle on the final glideslope. It's an interesting balance actually. Too fast and when you hit the HAC you will not be able to turn in (i.e. you skid out of the turn despite being banked at 60 degrees and pulling up hard). To handle this - switch the HAC geometry to the far side, and adjust the HAC radius big enough to roll round the turn without having to pull up too hard.

If you are coming in too slow, and you will need to switch the geometry to straight-in and eke it out to the runway. If you get it just right, you can glide around the HC without bleeding off too much energy, and arrive at the top of outer glideslope at a 20 degree perfect angle.

If you are coming in too high, then you will also have problems turning, as the air is less thick, so the ship doesn't bite enough.

The only interesting one is low and fast, where you have turning authority, so you can do a climb, loop and turn to transfer velocity into potential energy.

Over to the final approach, you have two sighting points - the PAPI and the VASI. If you are used to any flight sim flying (or real Cessnas for that matter), this is a weird concept, but the goal is to come down the outer glideslope at the 20 degree angle, to about 100-200m alt, then pull up smoothly onto the inner glideslope at 1.5 degrees, and kiss the runway really gently (holding the velocity vector just on the target touchdown point).

Find an approach range you are comfortable with (e.g. some of the Glideslope saved scenarios), and run them 20 or 30 times, adjusting by small amounts each time to develop a feel for spotting and correcting deviations from a perfect trajectory. It gets better with practice, I promise!

 

[Cras]

Glideslope was a great addon, but Glideslope 2.0 is just flat out amazing. I always use it for every space plane landing I do, be it Space Shuttle or XR-2 or G42. Even if it is just for the horizontal sit screen and for the HAC, it provides great information, and I cannot get enough information.

 

[worir1]

May i ask what is HAC or rather what does it stand for?

 

[kamaz]

May i ask what is HAC or rather what does it stand for?

See here: http://wiki.ssm-fans.info/landing

 

[garyw]

May i ask what is HAC or rather what does it stand for?

Heading alignment circle.

It's very well described in the glideslope documentation, the whole idea for landing on a runway deadstick is to come in with a bit of excess energy which you can spend on a HAC. If you don't have enough energy you make the HAC small, if you have too much energy you make it large. it's a really nice final bit of energy management.

 

[worir1]

Ah i understand. Thank you, both of you.

 

[Hielor]

I believe it's actually "heading alignment cone", since it describes an imaginary "cone" in space on which the maneuver should take place...

 

[garyw]

I believe it's actually "heading alignment cone",

or cylinder. it does get called a few different things, just have a look at the shuttle landing videos on you tube.

 

[ADSWNJ]

Glideslope was a great addon, but Glideslope 2.0 is just flat out amazing. I always use it for every space plane landing I do, be it Space Shuttle or XR-2 or G42. Even if it is just for the horizontal sit screen and for the HAC, it provides great information, and I cannot get enough information.

If you like Glideslope 2, you'll love my next project. It's in a few pieces right now, but I am building a Rendezvous Orientation MFD for super-precise docking, complete with a true heads-up display (courtesy of Enjo's HUD hooker). Even the rough version is looking sweet right now. I'll release it on a Tuesday sometime soon...

~~~
A couple more details, to whet the appetite:

Three modes ...
1. Orientation to the relative velocity vector, to null out the relative velocity to hold station.
2. Orientation and translation to a docking alignment waypoint a configurable number of meters in front of the port. (Removing the guesswork for when you are in the alignment corridor.)
3. Full 6-axis alignment into docking (left/right, up/down, forward/aft, yaw, pitch, roll), down to amazing precision.


The HUD has color coded arrows with error amount and error rate. Plus same data slaved in digital form to the MFD.

 

[n122vu]

or cylinder. it does get called a few different things, just have a look at the shuttle landing videos on you tube.

I've also heard corridor thrown out there by NASA TV.

---------- Post added at 08:51 PM ---------- Previous post was at 08:19 PM ----------

I'd also recommend practicing the 'On Final Approach to KSC' scenario included with the XR2 for anyone wanting to practice landing the XR2 with the keyboard.

 

[Cras]

Whatever you want to call it, it is actually a cone, it tightens up as your go down in altitude. And the SCOM calls it by Heading Alignment Cone and only by Heading Alignment Cone. So there you go.

Also, ADSWNJ that sounds like a very very useful tool indeed. If you want another tester for the project, that one or any future Glideslope updates you have in mind, don't hesitate to send me a PM. I will be more than happy to help where I can.