Fenix: reversers have no impact in the landing calculations?

[Andreas Stangenes 1,628]

Just wondering why planning for reverse idle or max reverse seemingly has no impact on the landing distance calculations in the EFB?

Edited May 21, 2022 by Andreas Stangenes

[Aamir 2,907]

They do, but only very minutely. It's.. not very useful I'm afraid.

[Cmmcd87 82]

9 minutes ago, Andreas Stangenes said:

Just wondering why planning for reverse idle or max reverse seemingly has no impact on the landing distance calculations in the EFB?

Because in real life with automatic braking selected and good braking conditions they also don’t, it’s mostly to reduce wear and tear on the brakes, the braking distance remains the same the brakes simply don’t apply as hard as they’d have to if the reversers weren’t used.

Edited May 21, 2022 by Carlosmmcd

[chapstick 2,757]

If you change the runway condition you'll see that it makes a difference on contaminated runways. 

[Andreas Stangenes 1,628]

Thanks, guys! Still learning, this padawan is. 

[2reds2whites 827]

The autobrake setting is a deceleration target, not a fixed amount of brake pressure. 

If for example you set autobrake low and full reverse, on landing the aircraft might not apply ANY brakes, because the deceleration target is being met from the thrust reversers alone. It does not 'sum' the autobrake and reverse.

Note that I don't have the Fenix EFB in front of me so it could be a bug, but you could experiment with contaminated runways and it should make a difference.

[Fiorentoni 4,114]

2 minutes ago, 2reds2whites said:

The autobrake setting is a deceleration target, not a fixed amount of brake pressure. 

If for example you set autobrake low and full reverse, on landing the aircraft might not apply ANY brakes, because the deceleration target is being met from the thrust reversers alone. It does not 'sum' the autobrake and reverse.

Note that I don't have the Fenix EFB in front of me so it could be a bug, but you could experiment with contaminated runways and it should make a difference.

Yes, exactly. Very good explanation. On contaminated runways MAX reversers give about 10% less landing distance, so that works too (in the calculations).

[regis9 3,999]

2 hours ago, 2reds2whites said:

The autobrake setting is a deceleration target, not a fixed amount of brake pressure. 

Thank you for that great explanation, I didn’t realize that.