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View Full Version : Question for the A109S guys regarding VG 1/2

turbineturkey
22nd Jan 2022, 17:22
Was starting up the other day and noticed when putting both inverters on the VG2 light turns off immediately while the VG1 light does not go out until completely spooled up.
I tried to put the SAS2 on once the VG2 light went out to test and it wouldn't let me until VG2 was fully spooled up. I thought it was strange one side acted differently than the other
but upon looking at the exact VG equipment installed for each side I found they were different. Here are the two installed:
Vertical gyro (No.1) 46060-11 Flight line System
Vertical gyro (No.2) VG-208 JET Electronics

Could it be that they are just designed differently? VG1 warning light will not extinguish until the Flight Line system is spooled up while the VG2 / JET Electronics
system may have the light go out as soon as it gets powered (even though not fully spooled up)?

Any thoughts appreciated. ;-)
noooby
24th Jan 2022, 21:23
What does your local Leonardo Tech Rep say?
turbineturkey
25th Jan 2022, 06:31
Already have an email out to them but wanted to hear if anyone in the field had come across same thing.
VeeAny
25th Jan 2022, 20:45
Haven't got an S nearby to check it, but I seem to recall they take about 50 seconds from initial power on to putting out a "valid" signal.

Sounds like one of them is erroneously putting out the "I am valid" signal , I think there may even be more than one of these signals from each gyro (or it is split, as I've seen EFIS's trying to display VG information when still spinning up before). Perhaps ground power it and turn on all of the EFIS screens and see if you get one that shows attitude before it is erect.

Forgive my use of improper terminology but it's late where I am and IETP does not want to play, so can't look it up.
lelebebbel
26th Jan 2022, 01:36
On the 119, which uses the same system i believe, you can activate SAS as soon as the VG1/2 message disappears and no sooner. On some of them, it takes longer for one or both of the VGs to be ready, but I've never come across one where the message disappears as soon as power is applied