I was going to call it 2.6.3, but so many changes have been made, updates added, I think it requires a full point. Also, the header file has been streamlined a bit and some defines have changed. The PID gains have not, so if your plane flew well with 2.6 it will fly well, or even better with 2.7. BTW, this is the first release that has only been tested via HIL. I've never flown it for real because of the strong winds in the bay area right now. We'll see, but I think this will be the most stable release yet.
I've included a folder for connecting your ardupilot hardware to X-Plane. There are PNG files showing the configurations to make in the menus.
X-Plane supplies IMU data and airspeed data to Ardupilot so you must select the GPS_IMU option to connect.
New altitude estimation - Thanks to Ryan Beall for this one. This smooths out noisy altitude readings from GPS.
Takeoff and landing are now full features. Their use has been simplified and are assigned full flight modes which can be seen with a ground station.
New Fly by wire throttle command by Christof Schimd.
Updates altitude hold for those with airspeed sensors. Airspeed is now recorded in m/s instead of air pressure value. Since calibration for your particular pitot tube setup could be needed there is now a calibration value in the header file.
Improved stick mixing response for all modes.
Waypoints will be skipped if you miss them after one loop around. The number of degrees can be changed in the code so let me know how many is good.
Loiter hold has been improved.
Cross track gain now on by default.
Numerous bugs are gone.
Old, unused code and vars have been removed. Code has been reformatted and commented.
If you have any issues, please comment here and I'll get them fixed in the final release.