When I use V/S for initial climb after engaging the autopilot the autothrottle doesn't work so I end up manually controlling the throttle. Is that normal?

Cheers

I haven't tried yet, I'm away from my rig. Three questions:

• Do you mean the throttles roll back after you press V/S?

• How fast you were flying when that happened?

• And what airspeed did you have selected in the MCP?

I have never used V/S for the climb, always have used VNAV.

I do use it for descent when there’s not so many constraints or just want to manage manually, but no never for the climb.

You definitely have the autothrottle on ?

There isn’t any real use for v/s in climb. VNAV all the way up.

You would never use VS for climb in any airliner. FLC / IAS mode is always used (or VNAV which essentially uses FLC) as it provides speed protection against stall.

VS is used for descent.

2 hours ago, Noel said:

When I use V/S for initial climb after engaging the autopilot the autothrottle doesn't work so I end up manually controlling the throttle. Is that normal?

Cheers

Hand fly a departure with A/T engaged (speed dialed), Gear / flaps up, A/P ON and V/S works good.

A/T speed can be changed as well as V/S.

Edited Tuesday at 04:01 PM1 day by vonmar

21 minutes ago, JYW said:

You would never use VS for climb in any airliner. FLC / IAS mode is always used (or VNAV which essentially uses FLC) as it provides speed protection against stall.

VS is used for descent.

Airbus wise I would assume same for Boeing use v/s before you end up levelling off if you anticipate a further climb better for passenger comfort and to minimise speed, altitude busts. 1000ft before level off v/s 500-1000fpm.

As said above, no SOP will ever have you climbing in V/S mode. FLCH or VNAV as it provides protection and keeps the thrust levers at a consistent position.

Descending in V/S works when you need it.

Just now, carlanthony24 said:

Airbus wise I would assume same for Boeing use v/s before you end up levelling off if you anticipate a further climb better for passenger comfort and to minimise speed, altitude busts. 1000ft before level off v/s 500-1000fpm.

No, I never do that IRL with a climb in IAS and our Boeing pilots definitely do not.

The AP is good enough that it won’t bust an altitude unless you really set it up for failure.

The only time I use VS to climb IRL is if we’re step climbing 1000 feet or so at cruise, I’ll VS +500 and then when the speed rolls back to our SOP climb speed I’ll swap to IAS.

3 hours ago, Noel said:

When I use V/S for initial climb after engaging the autopilot the autothrottle doesn't work so I end up manually controlling the throttle. Is that normal?

Cheers

No, to answer your specific question, it is not normal.

A/T should work in V/S mode.

For example, as I previously mentioned, on a hand flown departure.

3 hours ago, Noel said:

When I use V/S for initial climb after engaging the autopilot the autothrottle doesn't work so I end up manually controlling the throttle. Is that normal?

Cheers

Keep in mind and observe the following:

V/S (Vertical Speed) Mode

V/S is an alternative vertical pitch mode that commands and maintains a selected rate of climb or descent.

When the V/S switch is selected:

• The Vertical Speed window opens and is initialized to the airplane's current vertical speed (ROC/ROD).

• The IAS/MACH window displays the currently active airspeed or Mach value, which becomes the speed target.

• The AFDS changes the active pitch mode to V/S.

The autothrottle (A/T) automatically manages thrust to maintain the selected IAS/MACH target, with the specific thrust behavior depending on the active autothrottle mode (e.g., SPD, THR, THR REF). A/T should work in V/S mode.

The thrust levers may be manually repositioned without disconnecting the autothrottle. After they are released, the autothrottle repositions the thrust levers as necessary to satisfy the active autothrottle mode. The exception is HOLD mode, during which the autothrottle servo is disengaged from the thrust levers and will not reposition them.

Because V/S prioritizes maintaining the selected vertical speed, excessive climb or descent rates can result in significant airspeed deviations if the required performance exceeds the available thrust or drag. Continuous airspeed monitoring is therefore required when operating in V/S mode.

Edited Tuesday at 04:54 PM1 day by LRBS

1 hour ago, ATRguy said:

No, I never do that IRL with a climb in IAS and our Boeing pilots definitely do not.

The AP is good enough that it won’t bust an altitude unless you really set it up for failure.

The only time I use VS to climb IRL is if we’re step climbing 1000 feet or so at cruise, I’ll VS +500 and then when the speed rolls back to our SOP climb speed I’ll swap to IAS.

Fair enough Airbus a little different

2 hours ago, vonmar said:

No, to answer your specific question, it is not normal.

A/T should work in V/S mode.

For example, as I previously mentioned, on a hand flown departure.

I must be in a wrong A/T mode because let's say I set initial climb at 2000'/m and set speed to 220, despite autothrottle being on it just zooms way past 250 at which point I pull the levers down.

Can you post a screenshot of your PFD? That will show what your active autopilot and autothrottle modes are.

10 minutes ago, Noel said:

I must be in a wrong A/T mode because let's say I set initial climb at 2000'/m and set speed to 220, despite autothrottle being on it just zooms way past 250 at which point I pull the levers down.

What was your state initially?

For example: Altitude hold 3000' , 220 kt, A/P On, A/T On and a New alt dialed?