lionel wrote:
And the alignment takes far less that “a few minutes”. I’d say something like 10s to 30s?
On our aircraft it always takes longer than 30 seconds, but not several minutes either.
I have first-hand knowledge that a G500 will realign in flight, in cloud/IMC (somewhat turbulent, but not horribly so) when its power is cycled. However, time certainly feels longer during that time
The G1000 can also realign in flight. It happened to me after a temporary failure and restart of the AHRS.
This is what the manual has to say on the matter:
On the PFD, the AHRS begins to initialize and displays “AHRS ALIGN: Keep Wings Level”. The AHRS should display valid attitude and heading fields typically within the first minute of power-up. The AHRS can align itself both while taxiing and during level flight.
NOTE: In-flight initialization of AHRS, when operating without any valid source of GPS data and at true air speed values greater than approximately 200 knots, is not guaranteed. Under these rare conditions, it is possible for in-flight AHRS initialization to take an indefinite amount of time which would result in an extended period of time where valid AHRS outputs are unavailable.
Okay tried this yesterday and it worked, there is actually a CB just for AHRS so I pulled that one, waited a few seconds and then popped it back in. PFD displayed X and then the usual AHRS alignment message. The process took a bit longer than when it’s done on the ground but the result was a nicely aligned AI. I did it in the air because I forgot when taxiing :-D
I still wonder if maybe there is something wrong with the AHRS in this aircraft though if it is supposed to compensate for wonky ramps?
Deephack wrote:
I still wonder if maybe there is something wrong with the AHRS in this aircraft though if it is supposed to compensate for wonky ramps?
Does the ramp lead to ground position of the aircraft that is more than than 20 degrees of roll or more than 5 degrees of pitch away from the horizontal? 5 degrees is a slope of 8.7% and 20 degrees is 36.4%.
No, I would say that it’s more like 3 degrees so perhaps I need to add a remark to the logbook.
