A320 NAV DES SPD - - - Sometimes no speed fork

FrankLFRS · October 30, 2020 at 7:41 PM

Hi.

Sometimes we lost the limits speed min max in descent mode (all managed).

It may be normal or not!?

Jet-Pack (IPACS) · October 30, 2020 at 7:56 PM Official Post

When a speed constraint is active and the aircraft flies on a geometric descent profile (instead of idle glide) we currently have the managed speed at a fixed value. I'm not 100% sure if this is the same in the real aircraft but it would not make sense to have a speed range when you're not using idle thrust.

FrankLFRS · October 30, 2020 at 9:48 PM

It’s not a problem. I was used to have this range all the way down in the previous version.

However, I believe that under 10000 ft the range disappears. Sometimes we also have 255/230 kts range and sometimes 250 kts.

Thanks for the answer

FrankLFRS · November 1, 2020 at 1:29 PM

Quote from Jet-Pack (IPACS)

but it would not make sense to have a speed range when you're not using idle thrust

I’m not sure it’s a non sense.

With a car there’s a method called pulse and glide to have a very very very low consumption. You accelerate and you set neutral engine idle and let the car slowing down and again you accelerate... and so on.

Ok the other drivers won’t love you but it’s efficient. This is what the Prius does in some kind of ways without slowing down.