I am new to this bird and Airbus in general, so today made some taxi practice with empty plane and 3T of fuel. 

I know that light plane with idle thrust will move or even accelerate easily, but during taxi i have moved throttles to first reverse detent, and to my surprise plane was still accelerating during taxi.

Is it normal for light Airbus or some bug?

1 minute ago, Beardyman said:

I am new to this bird and Airbus in general, so today made some taxi practice with empty plane and 3T of fuel. 

I know that light plane with idle thrust will move or even accelerate easily, but during taxi i have moved throttles to first reverse detent, and to my surprise plane was still accelerating during taxi.

Is it normal for light Airbus or some bug?

If you were rolling downhill, yes.

EPWA is flat as table 🙂

One of the RW A320 pilots mentioned this in their stream, and is actually accurate. He stated they have to apply brakes quite often in  the A320 during taxi, even on level ground.

1 hour ago, Beardyman said:

 but during taxi i have moved throttles to first reverse detent, and to my surprise plane was still accelerating during taxi.

I think this is probably accurate with how reverse thrust on modern high-bypass engines works.

When reverse is engaged, most air is actually diverted outwards rather than forwards. This creates a huge amount of drag at higher speeds in order to slow down but it doesn't actually create much thrust to move backwards like the older systems which used buckets to divert more air forwards.

Edited May 27, 20224 yr by Tom Wright

Make sure you have calibrated you throttle. You must do that.

As for Taxi, the technique is to corner around 7kts 10 max, straight line on a long taxi let it reach 30 kts brake down to 10-15kts and release. Dont keep riding the brake becasue they will over heat in the Fenix.

 

 

 

2 hours ago, Tom Wright said:

I think this is probably accurate with how reverse thrust on modern high-bypass engines works.

When reverse is engaged, most air is actually diverted outwards rather than forwards. This creates a huge amount of drag at higher speeds in order to slow down but it doesn't actually create much thrust to move backwards like the older systems which used buckets to divert more air forwards.

Tom, most probably u are right - thx

2 hours ago, Tom Wright said:

I think this is probably accurate with how reverse thrust on modern high-bypass engines works.

When reverse is engaged, most air is actually diverted outwards rather than forwards. This creates a huge amount of drag at higher speeds in order to slow down but it doesn't actually create much thrust to move backwards like the older systems which used buckets to divert more air forwards.

I can see how it wouldn't be producing much reverse thrust, but my understanding was always that idle reverse should at least eliminate all forward thrust. The OP is saying that they're still accelerating in idle reverse, which does seem odd to me. Can that really be right?

To the OP: Can you verify that you are in fact in idle reverse when you observe this, i. e. do you see a green "REV" on your N1 gauges? 

The IAE engine variant will roll on idle.

The CFM engine variant needs around 26-28% N1 to "breakaway" - keep this power on until you reach the speed you'd want to be doing, then bring them back to idle. It will happily lazily roll around and maintain (or if light - accelerate very slowly) your speed. 

5 hours ago, martinboehme said:

I can see how it wouldn't be producing much reverse thrust, but my understanding was always that idle reverse should at least eliminate all forward thrust. The OP is saying that they're still accelerating in idle reverse, which does seem odd to me. Can that really be right?

To the OP: Can you verify that you are in fact in idle reverse when you observe this, i. e. do you see a green "REV" on your N1 gauges? 

Yes, confirm that rev is displayed. U can try similar scenario.

Edited May 27, 20224 yr by Beardyman