As I understand it SPEEDBRAKES do display as ARMED in the upper EICAS display when armed but there is no display for them when they are EXTENDED.

You can only see this if you visually check the lever on the pedestal.

Is that correct ?

Hi,

To my knowledge there are only two EICAS messages regarding the speedbrakes:

_ SPEEDBRAKES EXT > Whenever the speedbrakes are extended at inappropriate flight condition

_ SPEEDBRAKE ARMED > When the speedbrakes are armed

No EICAS message for the speedbrakes extended.

Quote

_ SPEEDBRAKES EXT > Whenever the speedbrakes are extended at inappropriate flight condition

 

The logic is:

Speedbrakes beyond ARM detent (some manuals say 15 degrees or more)

and any one of the following:

1) Aircraft between 15 and 800 feet

2) Flaps in landing range (25/30) and Radio Altitude greater than 15 feet

3) Two or more thrust levers are (about) 5 degrees or more above idle and Radio Altitude is greater than 15 feet

3 hours ago, Kyprianos Biris said:

but there is no display for them when they are EXTENDED.

Not unless they are extended less than about 7 degrees.

Cheers

JHW

On 3/22/2017 at 3:55 AM, Kyprianos Biris said:

As I understand it SPEEDBRAKES do display as ARMED in the upper EICAS display when armed but there is no display for them when they are EXTENDED.

You can only see this if you visually check the lever on the pedestal.

Is that correct ?

That is correct and that is why the PM on landing will call "SpeedBrakes UP" as one of his calls. SpeedBrakes,weight on wheels, and braking, are way more important than reverse thrust in stopping the jet.

So, the normal calls on landing by the PM are "SpeedBrakes Up, Reversers Normal, and 60 knots". Some airlines will call 80 and 60, the calls listed are standard Boeing calls.

As you can guess, the PF is focused outside on maintaining directional control and though he can see the SB Lever move, he does not want to swivel his head to verify they are fully up, so it is the PM job to ensure that. If they don't move, the call would be "Speedbrakes NOT Up" and the PF would deploy them manually, before reverse is applied.