Hi Nigel
I don't normally do much adjusting of flight level once I'm up, so I've just had a test & it worked better than expected.
I'm wondering if you're using a repaint & haven't got the aircraft.cfg settings that the 510ED needs.
Check your aircraft.cfg autopilot section, the red bit is unusual but important to the function of the 510 A/P. There are some other small differences in this section from the regular 1-11, these are for the 510's auto land.
[autopilot]
autopilot_available=1
flight_director_available=1
default_vertical_speed=1.000000
autothrottle_available=1
autothrottle_arming_required=1
autothrottle_takeoff_ga=1
autothrottle_max_rpm=95.000000
pitch_takeoff_ga=8.000000
USE_NO_DEFAULT_PITCH=1
USE_NO_DEFAULT_BANK=1
default_pitch_mode=0
default_bank_mode=0
max_pitch=10.000000
max_pitch_acceleration=1.000000
max_pitch_velocity_lo_alt=2.000000
max_pitch_velocity_hi_alt=1.500000
max_pitch_velocity_lo_alt_breakpoint=20000.000000
max_pitch_velocity_hi_alt_breakpoint=28000.000000
max_bank=25.000000
max_bank_acceleration=1.800000
max_bank_velocity=3.000000
max_throttle_rate=0.100000
nav_proportional_control=15.000000
nav_integrator_control=0.250000
nav_derivative_control=0.000000
nav_integrator_boundary=2.500000
nav_derivative_boundary=0.000000
gs_proportional_control=12.520000
gs_integrator_control=0.260000
gs_derivative_control=0.000000
gs_integrator_boundary=0.700000
gs_derivative_boundary=0.000000
yaw_damper_gain=1.000000
This is how it's supposed to behave.
It holds the current vertical speed when A/P is engaged.
Alt Lock then obviously alters VS to zero & holds current altitude.
With Alt Lock engaged, you can dial in a new target altitude & when you switch to Alt Acquire you then need to use the pitch wheel to adjust VS to get there.
If the altitude difference is only small, FS will usually aquire the new height automatically even though I'm telling it not to in the XML code!
That's why I said the test worked better than expected, in jumps of 1000ft it was correctly waiting for me to set the VS with the pitch wheel. It acquires a 500ft FL difference itself for some reason. :think:
DM