Reentries are awesome. It took me a while to master a foolproof reentry procedure for the XR / DG IV. But after sorting out the right combination of MFD's and workflows, I can now land at any base from any orbit of 1000KM or less successfully EVERY TIME.
Here's a fairly detailed outline of the procedure:
First you need the following MFD's:
[ame="http://www.orbithangar.com/searchid.php?ID=2139"]Aerobrake[/ame]
Base Sync
[ame="http://www.orbithangar.com/searchid.php?ID=2763"]Glide Slope[/ame]
If using the XR2/XR5 I also like to edit the Preferences CFG and increase the maximum autopilot bank and pitch angles to 85 degrees (also handy for other atmospheric maneuvers not covered here).
Outline:
1. Starting in a roughly circular orbit of any altitude between ~200 KM and 1000 KM we conduct a burn normal to our orbit while using Base Sync MFD so as to place our flight path directly over our chosen landing site at least one full orbit in the future.
2. Precisely one half orbit (in Base Sync) before passing over the landing site begin a full thrust retrograde burn using main engines until Perapsis altitude equals zero.
3. Activate Aerobrake MFD and target your landing site. Hit PG and PRJ to bring up the reentry map. As you approach entry interface (~90 KM) activate the attitude hold/reentry autopilot and adjust your angle of attack (AOA, not pitch) to place the end of your predicted flight path on your landing site as displayed in Aerobrake MFD (~35-37 degrees ballpark). As you descend, continuously monitor and adjust AOA as necessary to keep the end of your flight path on target. This is the longest phase of the reentry.
4. At around Mach 8-7 activate Glideslope MFD on both screens. Hit NB/PB until desired landing site is displayed. Monitor altitude/speed (Alt/Spd line graph, not the 6 columns of numbers) on one screen and horizontal (HAC) alignment (Az) on the other. The altitude/speed profile is optimized for the space shuttle, but is close enough to be useful with the XR/DG. Now use your vessel's slope indicator to help you stay on the yellow altitude line. Speed (the green line) will take care of itself as long as you maintain the correct altitude profile. Remember increasing AOA will steepen your descent and vice versa.
5. At around Mach 2 you should be approaching the HAC. Reduce your AOA to nearly zero. Replace the Altitude/Speed graph screen with Surface MFD in IAS mode. Adjust your vessel's slope angle to intercept and maintain a 20 degree descent throughout the HAC as displayed by the glideslope indicator on the right side of the HAC alignment screen (Glideslope MFD). Use air brakes to maintain 190-200 M/S IAS.
6. As you approach the end of the HAC the runway should appear in front of you. Disengage autopilot, preflare, dump the gear and land normally.
Do's and Don't's:
- DON'T use time compression after activating the autopilot. YOU HAVE BEEN WARNED. :nono:
- DON'T forget to configure your ship for reentry (IE stow the radiator). Activate your airfoil surfaces.
- DO set up your screens in advance. You can preselect the desired base in Glideslope MFD and Aerobrake MFD well before you need it. This reduces your workload later on. Also, preselect your airspeed mode in Surface MFD (IAS) and tune your navaids. Having the HSI in ILS mode as you roll out of the HAC and line up with the runway is handy.
- DO monitor your AOA, flight path prediction, and descent rates closely. The XR autopilot gives you much more control over your AOA (0.5 degree increments). I highly recommend practicing reentries in that vessel. A little goes a long way, especially up high near entry interface.
- DO practice and have fun!!!:thumbup: