Airbus nose gear - Typically how long in air after main gear touchdown?
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ACTUATION LOGIC
Deployment requires :
‐ One FADEC channel, operating with its associated throttle reverse signal ;
‐ Right and left main gear compressed signal from the corresponding LGCIUs ;
‐ A Thrust Lever Angle (TLA) reverse signals from at least one Spoiler Elevator Computer.
Doesn't say a word about nose wheel.
Deployment requires :
‐ One FADEC channel, operating with its associated throttle reverse signal ;
‐ Right and left main gear compressed signal from the corresponding LGCIUs ;
‐ A Thrust Lever Angle (TLA) reverse signals from at least one Spoiler Elevator Computer.
Doesn't say a word about nose wheel.
Only half a speed-brake
Because, vilas, you are quoting the logic of the actual system.
The OP is trying to find a suggestion for a software monitoring routine of that system. At the moment the their setup is
OPEN IN FLIGHT => Failure message generated
OPEN ON GROUND => all good.
Unfortunately, ON GROUND and IN FLIGHT is already coded in that monitoring software via “phase” concept, ON GROUND being triggered by NLG weight-on-wheels. Which create false warnings every landing, because pilots do open REV well before NLG because
- it is the right thing to do
- it is certified as such
- the logic of the actual system (which you described) allows it
The OP is trying to find a suggestion for a software monitoring routine of that system. At the moment the their setup is
OPEN IN FLIGHT => Failure message generated
OPEN ON GROUND => all good.
Unfortunately, ON GROUND and IN FLIGHT is already coded in that monitoring software via “phase” concept, ON GROUND being triggered by NLG weight-on-wheels. Which create false warnings every landing, because pilots do open REV well before NLG because
- it is the right thing to do
- it is certified as such
- the logic of the actual system (which you described) allows it
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Is the answer contained within your first posting?
Why does the alert logic consider the aircraft "in the air" when the MLG are on the ground?
For the purposes of TRU warnings, that's wrong. Are there other systems or circumstances under which MLG on the ground but nosewheel in the air should be counted as "in the air?"
Seems the problem would go away if the TRU alert logic looked for "MLG not on the ground" instead of "aircraft in the air" as a gating condition.
For the purposes of TRU warnings, that's wrong. Are there other systems or circumstances under which MLG on the ground but nosewheel in the air should be counted as "in the air?"
Seems the problem would go away if the TRU alert logic looked for "MLG not on the ground" instead of "aircraft in the air" as a gating condition.
Does this problem affect all aircraft of the type, or just one?
If one, then why only that specific aircraft?
If all of them then 1) why wasn't this fixed already and 2) presumably you work for Airbus so isn't there anyone there you could ask?
If one, then why only that specific aircraft?
If all of them then 1) why wasn't this fixed already and 2) presumably you work for Airbus so isn't there anyone there you could ask?
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A few have asked why this issue hasn’t been fixed already. It was discovered just a few weeks ago. It’s not a safety concern, so I would suggest the fix would be fairly timely. I’m curious what sort of timescales some of you expect.
Thanks for the helpful responses. We have a solution.
Thanks for the helpful responses. We have a solution.
Last edited by Hodd; 29th Jan 2018 at 20:39.
Can the system detect that the TRU is unlocked if the pilot hasn't selected reverse (e.g. because there's a separate mechanical lock that releases on ground even if the reversers haven't been selected)?
If not, it seems like the best chance to detect a fault (before it's too late) might be if the pilot selects reverse a second or two early and the TRU unlocks when it shouldn't. If you delay the alarm a fixed number of seconds, you're likely to also lose coverage for those critical couple of seconds before there's weight on the main gear.
If not, it seems like the best chance to detect a fault (before it's too late) might be if the pilot selects reverse a second or two early and the TRU unlocks when it shouldn't. If you delay the alarm a fixed number of seconds, you're likely to also lose coverage for those critical couple of seconds before there's weight on the main gear.
