AH precession (not as a result of Gyro toppling) is overdone. AH errorrs after extreme manoeuvering (i.e. Gyro limits excedded) is well done. There are 2 possible AH versions the MKI and the MKII each has slightly differrent limits. the limits as detailed in the AP1257 are:
MKI +-60 degrees in Pitch, +- 90 degree in Roll
MKII +_45 degrees in pitch, +- 360 degrees in roll
Following a a complete topple the AP1257 states that up to 10mins in 1G unaccelerated flight may be required for the AH to erect. In addition these AH also exhibited acceleration errors that required pilot allowance in the pitch axis. Typically on take off acceleration resulted in the AH displaying an artificially higher than correct pitch attitude. To prevent settling back to terra firma in an IF Take off pilots typically added an "extra Bar width" in pitch until the climb IAS was achieved. With no linear acceleration Pitch info was reliable.
There is good video of the degree of precession that occurs in an In cockpit and external cockpit split view of a Hurricane MKI Air display. This aircraft is equipped with original instruments MKII AH it seems. This is a 10 min display that includes many rolling manoeuvres and Pitch manoeuvres. The video is in the hands of the devs.
Last edited by IvanK; 04-17-2011 at 12:00 AM.
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