A321 Parking Brake Issue – Aircraft Rolls with No Thrust

1st Official Post

    Hello IPACS Team,

    I would like to report a potential issue regarding the A321.

    After landing and taxiing to the gate, when I set the parking brake, the aircraft continues to roll forward even though both engines are shut down and there is zero thrust. There is no N1/N2 indication or residual thrust, yet the aircraft still moves with the parking brake engaged.

    Interestingly, when I release the parking brake again, the aircraft then remains completely stationary and does not move at all.

    This behavior seems physically incorrect, as the aircraft should remain fully stopped when the parking brake is set, especially with engines off and no external forces applied.

    I am not sure if this issue is specific to the A321 or affects other aircraft as well, but I have observed it on the A321 so far.

    Thank you for your time and support.

    Best regards.

    Quote from Jet-Pack (IPACS)

    Normally you don't even need the parking brake to stay put, that's why a slope is needed to get the plane to roll without thrust.

    I'll investigate, probably has to do with not switching to the alternate braking correctly.

    Do you know what's really strange, Jan? When I activate the parking brake, the wheels move, but when I deactivate it, the wheels stop. This problem occurs after the flight, that is, after landing. And this problem didn't just appear now. I saw this problem 4-5 months ago, but I assumed you were aware of it and didn't feel the need to post about it on the forum. I'd also like to add that this problem doesn't occur at every airport. It happens in places where the plane is moving freely in "idle" mode. So, I think there's a slope involved. But the parking brake should prevent this.

    • Official Post
    Quote from poyraz_tr51

    Do you know what's really strange, Jan? When I activate the parking brake, the wheels move, but when I deactivate it, the wheels stop. This problem occurs after the flight, that is, after landing. And this problem didn't just appear now. I saw this problem 4-5 months ago, but I assumed you were aware of it and didn't feel the need to post about it on the forum. I'd also like to add that this problem doesn't occur at every airport. It happens in places where the plane is moving freely in "idle" mode. So, I think there's a slope involved. But the parking brake should prevent this.

    I also noticed that you have no brakes when you have dual engine failure, so it must be missing something like the accumulator pressure or the logic is inverted... Though I could stop with the parking brake after my 'dead stick' landing without engines.

    Quote from Jet-Pack (IPACS)

    Normally you don't even need the parking brake to stay put, that's why a slope is needed to get the plane to roll without thrust.

    I'll investigate, probably has to do with not switching to the alternate braking correctly.

    Jan, I completely shut down the plane yesterday because SEQM airport doesn't have a "cold and dark" feature. Now I've prepared the plane to continue where I left off. However, even with the APU engaged, the pushback vehicle couldn't move the aircraft. I started the engines, and only then did it push the plane.