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Flying the Shuttle - Final Approach: Difference between revisions
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Flying the Shuttle - Final Approach (view source)
Revision as of 16:47, 19 October 2017
, 19 October 2017→The last five minutes - a tutorial
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== The last five minutes - a tutorial == | == The last five minutes - a tutorial == | ||
(written for the devel version of | (written for the devel version of Oct. 2017) | ||
{{Note|This tutorial is for an | {{Note|This tutorial is for an up to date version of the official [http://www.science-and-fiction.org/bookstore.html Flightgear Space Shuttle Flight Manual].}} | ||
<i>In this tutorial, you'll learn to read the Shuttle avionics to fly from TAEM interface into the final approach on instruments only.</i> | <i>In this tutorial, you'll learn to read the Shuttle avionics to fly from TAEM interface into the final approach on instruments only.</i> | ||
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* Start Flightgear with the commandline options | * Start Flightgear with the commandline options | ||
<code>--aircraft=SpaceShuttle-TAEM --airport= | <code>--aircraft=SpaceShuttle-TAEM --airport=KVBG </code> | ||
* You're about 60 miles away from | * You're about 60 miles away from Vandenberg AFB. We (intentionally) didn't specify winds, so you might be coming in from any direction - the point of TAEM guidance is that it leads you into the proper approach no matter how you come in. Well, first we need to tell the avionics we actually want to land at Vandenberg, so open <b>Space Shuttle -> Entry Guidance</b> and select Vandenberg AFB as the landing site. | ||
[[File: | [[File:TAEM init.jpg|1000px]]<br /> | ||
<br /> | |||
[[File:Visual 111.jpg|1000px]] | |||
* The right displays (VERT SIT and HORIZ SIT) should already be selected, if not, bring them up. With TAEM guidance active, they should come alive and show a yellow Shuttle symbol sliding down from the upper right to the lower left vertically and three small circles extending from the Shuttle forward horizontally. | * The right displays (VERT SIT and HORIZ SIT) should already be selected, if not, bring them up. With TAEM guidance active, they should come alive and show a yellow Shuttle symbol sliding down from the upper right to the lower left vertically and three small circles extending from the Shuttle forward horizontally. | ||
The idea is simple - we aim to keep the Shuttle symbol on the central trajectory vertically by changing pitch (and deploying speedbrake if we need to dissipate additional energy). | The idea is simple - we aim to keep the Shuttle symbol on the central trajectory vertically by changing pitch (and deploying speedbrake if we need to dissipate additional energy). | ||
A couple of things to do if you don't come for the Entry Tutorial. | |||
For that, you can use time compression and decrease it, everything happens fast now, so buy you some time. | |||
We will check on '''SPEC 51 PRO''' the probes value ( Mach, Altitude, Alpha angle) and compared them to those Primary Flight Display fed by the IMU so far. | |||
[[File:SPEC 51 ADTA.jpg|1000px]] | |||
If everything looks good ie. quite close, we can incorporate ADTA to Guidance and Control Software with ''ITEM 28 EXEC''.<br /> | |||
PFD will be fed by Air Data Probes now. | |||
We also incorporate TACAN and Altitude from ADTA (Kalmann Filters) into navigation filter to update the State vector ( SV) by '''ITEM 19 EXEC''' and '''ITEM 25 EXEC''' | |||
[[File:SPEC 50 kalmann.jpg|1000px]] | |||
You can also ask to MCC the last QNH (Atmospherical pressure at sea level) and update it into the Spec 50 display, here '''ITEM 9 +30.00 EXEC''' | |||
[[File:QNH 1.jpg|1000px]] | |||
Finally, MLS Channel presets ( done in Orbit befor entry normally) according to the Landing Runway you chose. | |||
[[File:MLS 1.jpg|800px]] | |||
Horizontally the trajectory predictors tell where we'll be in 20, 40 and 60 seconds if we keep the current state. We can use them to aim for the heading alignment cone (HAC) intercept point as soon as it becomes visible. For the time being, just make sure we're going with about 240 KEAS and stay on the vertical trajectory, don't maneuver much horizontally. | Horizontally the trajectory predictors tell where we'll be in 20, 40 and 60 seconds if we keep the current state. We can use them to aim for the heading alignment cone (HAC) intercept point as soon as it becomes visible. For the time being, just make sure we're going with about 240 KEAS and stay on the vertical trajectory, don't maneuver much horizontally. | ||
[[File: | [[File:TAEM 1.jpg|1000px]] | ||
Expect extremely high descent rates during the whole pattern - in subsonic flight, the Shuttle drops a good 7000 ft/min, in the early supersonic stage it might drop even faster than this to stay on the trajectory. The glide ratio you can expect at best is some 4.5 in the late phases of the approach (a typical airliner might be closer to 20), so you're not flying a very nimble vessel. The only thing that makes TAEM work is that we come in extremely high and fast and thus have plenty of energy to dissipate. | Expect extremely high descent rates during the whole pattern - in subsonic flight, the Shuttle drops a good 7000 ft/min, in the early supersonic stage it might drop even faster than this to stay on the trajectory. The glide ratio you can expect at best is some 4.5 in the late phases of the approach (a typical airliner might be closer to 20), so you're not flying a very nimble vessel. The only thing that makes TAEM work is that we come in extremely high and fast and thus have plenty of energy to dissipate. | ||
Going Subsonic, back to Normal Ariplane speed and you can take manual control of the Orbiter wehn you point by going to '''CSS Pitch and CSS Roll/Yaw''' | |||
[[File: | [[File:Subsonic.jpg|1000px]] | ||
* A minute into the flight or so, you'll see the touchdown point and the HAC come into view. The aim point to intercept the HAC is on the tangent to the circle you're seeing such that when you fly around on the circle, you're led right into the line aiming at the touchdown point. Take a look at the red and blue annotations and their links with the HSI needles ( Center of HAC C, Tangent of HAC H). | |||
[[File:HSI needles.jpg|1000px]] | |||
Also marked are the TACAN azimuth and range readings - if you fly zero relative azimuth, you'll be led reasonably close to the intercept point. Do a gentle turn to change course towards the intercept point now (and always monitor the vertical situation!). | Also marked are the TACAN azimuth and range readings - if you fly zero relative azimuth, you'll be led reasonably close to the intercept point. Do a gentle turn to change course towards the intercept point now (and always monitor the vertical situation!). | ||
* If you have corrected course, you'll eventually reach the aim point. If the weather is good, you can take a peek outside - as we pass the touchdown point, you should be able to see | * If you have corrected course, you'll eventually reach the aim point. If the weather is good, you can take a peek outside - as we pass the touchdown point, you should be able to see Vandenberg AFB left underneath clouds as you pass by some 30.000 ft higher entering the HAC. | ||
[[File: | [[File:HAC visual.jpg|1000px]] | ||
Once you reach the intercept point, turn such that the track predictors fall right onto the circle, then you have the right turn radius. It's easy to lose control of airspeed or vertical situation at this point. Anticipate about a 30 degree bank angle and that you'll lose lift when turning, so if you have the speedbrake deployed, retract it a notch or two to compensate. | Once you reach the intercept point, turn such that the track predictors fall right onto the circle, then you have the right turn radius. It's easy to lose control of airspeed or vertical situation at this point. Anticipate about a 30 degree bank angle and that you'll lose lift when turning, so if you have the speedbrake deployed, retract it a notch or two to compensate. | ||
[[File: | [[File:HAC 1.jpg|1000px]] | ||
Last turn, a view by the Commander window | |||
[[File:HAC window view.jpg|1000px]] | |||
At 15000 feet, MLS becomes active (MLS in Yellow Spec 50). SV is more precise, and flight director in the HUD should give you precise guidance for navigation. | |||
[[File:MLS active.jpg|1000px]] | |||
If you've done well, you should be able to leave the HAC right where the line points to the touchdown point in long final. | |||
You see in the HUD that the virtual runway fed by IMU and Nav filters ( TACAN, MLS, GPS etc) is a bit to the left of the real one, this is due to Nav errors and IMU drift. No big deal, close enough for final guidance and you can adjust now visually the track. | |||
'''OGS''' ( Outer Glide Slope) is also active in the HUD, be prepared to take a 15 to 20 ° glide path | |||
[[File:FINAL OGS after the hac.jpg|1000px]]<br /> | |||
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[[File:Final visual.jpg|1000px]]<br /> | |||
<br /> | |||
Advice if you begin, Select Navigation Perfect to have the virtual runway exactly ot the real runway, it will help you with Final HUD guidance. | |||
[[File:NAv pefect.jpg|800px]]<br /> | |||
End the turn, wait for the Shuttle to stabilize and then push the nose down to get your visual of the runway - if you've done everything well, you should be somewhat high on energy for your final descent, so be prepared for liberal use of speedbrakes to get down to the touchdown point. Good luck for the final where time is going faster than ever. | |||
2000 feet RA, Preflare. '''FLARE''' and then '''IGS''' (Inner Glide Slope) in the HUD and we follow guidance carret to have to good pitch up rate. Also time to arm the Gear. You can declutter the HUD DLCT or Maj+D to have just essential informations in front of you. | |||
[[File:Flare 1.jpg|1000px]]<br /> | |||
Speed will bleed down from 330 kt to 210 kt for the Touch Down in 1 miles, pretty impressive.<br /> | |||
300 feet RA Gear Down, and smooth Final Flare ''FNLFL'' in the HUD with Ground Speed bottom left if you are in the Last Declutter mode. Flare is long, you will fly over at least a good km of the runway before touching at less than 6 ft/s of Vertical Speed Ideally. Look far in front of you and maintain the Flight Path Vector ( Circle) just below the horizon line and wait for the Touch around 200 kt. | |||
[[File:Final flare.jpg|1000px]]<br /> | |||
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[[File:Final flare visual.jpg|1000px]]<br /> | |||
<br /> | |||
Touch and activate the Drag Chute with Maj+C or with cockpit switch. | |||
[[File:Drag.jpg|1000px]]<br /> | |||
<br /> | |||
[[File:Drag visual.jpg|1000px]]<br /> | |||
Slowly brake and derotate and touch the Nose Wheel on the Runway. Below 60 kt, Chute Jetisson | |||
[[File:Chute jett.jpg|1000px]] | |||
Wheel Stopped, Welcome home and congratulations. You landed the most complex glider in the world!! | |||
[[File:Wheel stop.jpg|1000px]] | |||
== Further reading == | == Further reading == | ||