NAV engaged on ground - A320
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Joined: Oct 2015
Posts: 279
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From: 43N
NAV engaged on ground - A320
I had an aircraft where NAV indicated engaged while at the gate. We cycled the FD's. NAV then indicated armed but then immediately indicated engaged. We cycled the NAV data base dumping the FMGC and reinserted the flight plan. After reinserting the flight plan, NAV once again indicated engaged. At that point I was ready to dump the IR's and re align. It just so happened at that time the ground staff wanted external power disconnected. We did so and the power interruption/switch over fixed the NAV engaged problem and the FMA's indicated properly.
What was the reason for this anomaly?
What was the reason for this anomaly?
Joined: Oct 2013
Posts: 70
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From: U.S.
An abnormality in the power quality that is being delivered to a system is often referred to as "dirty power." Abnormalities can include low power factor, frequency variations, voltage variations, and surges/spikes.
Joined: Sep 2003
Posts: 502
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From: Dunnunda
Can happen if you inadvertently delete the departure threshold in the MCDU using a Direct-To or the like. FMS goes into climb mode and can engage NAV on the ground.
I wonder if pushing the EXT PB wokeup the ground logic.
I wonder if pushing the EXT PB wokeup the ground logic.
Last edited by Bula; 2nd March 2017 at 05:34.
Joined: Nov 1999
Aviation Qualifications: ATPL
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From: UK
An abnormality in the power quality that is being delivered to a system is often referred to as "dirty power." Abnormalities can include low power factor, frequency variations, voltage variations, and surges/spikes.
Having said that, I have never known this problem, but I have seen the power transfer from external power to APU, (or vice versa), sometimes cause faults in some systems.
Joined: Jun 2014
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From: Village of Santo Poco
